[gtk/path-work-rebased: 114/121] gtk-demo: Add a curve editor demo
- From: Matthias Clasen <matthiasc src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gtk/path-work-rebased: 114/121] gtk-demo: Add a curve editor demo
- Date: Sun, 5 Dec 2021 03:59:05 +0000 (UTC)
commit 21e71c395771589c63080fe481081d0cdfa53660
Author: Matthias Clasen <mclasen redhat com>
Date: Sat Dec 4 22:15:37 2021 -0500
gtk-demo: Add a curve editor demo
demos/gtk-demo/curve-editor.c | 2644 +++++++++++++++++++++++++++++++++++++
demos/gtk-demo/curve-editor.h | 36 +
demos/gtk-demo/curve.c | 272 ++++
demos/gtk-demo/demo.gresource.xml | 5 +
demos/gtk-demo/meson.build | 2 +
5 files changed, 2959 insertions(+)
---
diff --git a/demos/gtk-demo/curve-editor.c b/demos/gtk-demo/curve-editor.c
new file mode 100644
index 0000000000..81e1083e86
--- /dev/null
+++ b/demos/gtk-demo/curve-editor.c
@@ -0,0 +1,2644 @@
+#include "curve-editor.h"
+
+#include <gtk/gtk.h>
+
+#define DRAW_RADIUS 5
+#define CLICK_RADIUS 8
+
+/* {{{ Types and structures */
+
+static const char *
+op_to_string (GskPathOperation op)
+{
+ switch (op)
+ {
+ case GSK_PATH_MOVE:
+ return "move";
+ case GSK_PATH_LINE:
+ return "line";
+ case GSK_PATH_CURVE:
+ return "curve";
+ case GSK_PATH_CONIC:
+ return "conic";
+ case GSK_PATH_CLOSE:
+ return "close";
+ default:
+ g_assert_not_reached ();
+ }
+}
+
+static GskPathOperation
+op_from_string (const char *s)
+{
+ if (strcmp (s, "move") == 0)
+ return GSK_PATH_MOVE;
+ else if (strcmp (s, "line") == 0)
+ return GSK_PATH_LINE;
+ else if (strcmp (s, "curve") == 0)
+ return GSK_PATH_CURVE;
+ else if (strcmp (s, "conic") == 0)
+ return GSK_PATH_CONIC;
+ else if (strcmp (s, "close") == 0)
+ return GSK_PATH_CLOSE;
+ else
+ g_assert_not_reached ();
+}
+
+typedef enum
+{
+ CUSP,
+ SMOOTH,
+ SYMMETRIC,
+ AUTO
+} PointType;
+
+static const char *
+point_type_to_string (PointType type)
+{
+ switch (type)
+ {
+ case CUSP:
+ return "cusp";
+ case SMOOTH:
+ return "smooth";
+ case SYMMETRIC:
+ return "symmetric";
+ case AUTO:
+ return "auto";
+ default:
+ g_assert_not_reached ();
+ }
+}
+
+static PointType
+point_type_from_string (const char *s)
+{
+ if (strcmp (s, "cusp") == 0)
+ return CUSP;
+ else if (strcmp (s, "smooth") == 0)
+ return SMOOTH;
+ else if (strcmp (s, "symmetric") == 0)
+ return SYMMETRIC;
+ else if (strcmp (s, "auto") == 0)
+ return AUTO;
+ else
+ g_assert_not_reached ();
+}
+
+typedef struct
+{
+ GskPathOperation op;
+ graphene_point_t p[4];
+ float weight;
+ PointType type;
+ int dragged;
+ int hovered;
+} Segment;
+
+struct _CurveEditor
+{
+ GtkWidget parent_instance;
+ GArray *segments;
+ int context;
+ float context_pos;
+ gboolean edit;
+ int edited_point;
+ int edited_segment;
+ int molded;
+ int dragged;
+
+ GtkWidget *menu;
+ GActionMap *actions;
+ GskStroke *stroke;
+ GdkRGBA color;
+
+ gboolean show_outline;
+};
+
+struct _CurveEditorClass
+{
+ GtkWidgetClass parent_class;
+};
+
+G_DEFINE_TYPE (CurveEditor, curve_editor, GTK_TYPE_WIDGET)
+
+/* }}} */
+/* {{{ Misc. geometry */
+
+/* Set q to the projection of p onto the line through a and b */
+static void
+closest_point (const graphene_point_t *p,
+ const graphene_point_t *a,
+ const graphene_point_t *b,
+ graphene_point_t *q)
+{
+ graphene_vec2_t n;
+ graphene_vec2_t ap;
+ float t;
+
+ graphene_vec2_init (&n, b->x - a->x, b->y - a->y);
+ graphene_vec2_init (&ap, p->x - a->x, p->y - a->y);
+
+ t = graphene_vec2_dot (&ap, &n) / graphene_vec2_dot (&n, &n);
+
+ q->x = a->x + t * (b->x - a->x);
+ q->y = a->y + t * (b->y - a->y);
+}
+
+static void
+find_point_on_line (const graphene_point_t *p1,
+ const graphene_point_t *p2,
+ const graphene_point_t *q,
+ float *t)
+{
+ float tx = p2->x - p1->x;
+ float ty = p2->y - p1->y;
+ float sx = q->x - p1->x;
+ float sy = q->y - p1->y;
+
+ *t = (tx*sx + ty*sy) / (tx*tx + ty*ty);
+}
+
+/* Determine if p is on the line through a and b */
+static gboolean
+collinear (const graphene_point_t *p,
+ const graphene_point_t *a,
+ const graphene_point_t *b)
+{
+ graphene_point_t q;
+
+ closest_point (p, a, b, &q);
+
+ return graphene_point_near (p, &q, 0.0001);
+}
+
+/* Set q to the point on the line through p and a that is
+ * at a distance of d from p, on the opposite side
+ */
+static void
+opposite_point (const graphene_point_t *p,
+ const graphene_point_t *a,
+ float d,
+ graphene_point_t *q)
+{
+ graphene_vec2_t ap;
+ float t;
+
+ graphene_vec2_init (&ap, p->x - a->x, p->y - a->y);
+ t = - sqrt (d * d / graphene_vec2_dot (&ap, &ap));
+
+ q->x = p->x + t * (a->x - p->x);
+ q->y = p->y + t * (a->y - p->y);
+}
+
+/* Set q to the point on the line through p and a that is
+ * at a distance of d from p, on the same side
+ */
+static void
+scale_point (const graphene_point_t *p,
+ const graphene_point_t *a,
+ float d,
+ graphene_point_t *q)
+{
+ graphene_vec2_t ap;
+ float t;
+
+ graphene_vec2_init (&ap, p->x - a->x, p->y - a->y);
+ t = sqrt (d * d / graphene_vec2_dot (&ap, &ap));
+
+ q->x = p->x + t * (a->x - p->x);
+ q->y = p->y + t * (a->y - p->y);
+}
+
+/* Set p to the intersection of the lines through a, b
+ * and c, d
+ */
+static void
+line_intersection (const graphene_point_t *a,
+ const graphene_point_t *b,
+ const graphene_point_t *c,
+ const graphene_point_t *d,
+ graphene_point_t *p)
+{
+ double a1 = b->y - a->y;
+ double b1 = a->x - b->x;
+ double c1 = a1*a->x + b1*a->y;
+
+ double a2 = d->y - c->y;
+ double b2 = c->x - d->x;
+ double c2 = a2*c->x+ b2*c->y;
+
+ double det = a1*b2 - a2*b1;
+
+ if (det == 0)
+ {
+ p->x = NAN;
+ p->y = NAN;
+ }
+ else
+ {
+ p->x = (b2*c1 - b1*c2) / det;
+ p->y = (a1*c2 - a2*c1) / det;
+ }
+}
+
+/* Given 3 points, determine the center of a circle that
+ * passes through all of them.
+ */
+static void
+circle_through_points (const graphene_point_t *a,
+ const graphene_point_t *b,
+ const graphene_point_t *c,
+ graphene_point_t *center)
+{
+ graphene_point_t ab;
+ graphene_point_t ac;
+ graphene_point_t ab2;
+ graphene_point_t ac2;
+
+ ab.x = (a->x + b->x) / 2;
+ ab.y = (a->y + b->y) / 2;
+ ac.x = (a->x + c->x) / 2;
+ ac.y = (a->y + c->y) / 2;
+
+ ab2.x = ab.x + a->y - b->y;
+ ab2.y = ab.y + b->x - a->x;
+ ac2.x = ac.x + a->y - c->y;
+ ac2.y = ac.y + c->x - a->x;
+
+ line_intersection (&ab, &ab2, &ac, &ac2, center);
+}
+
+/* Return the cosine of the angle between b1 - a and b2 - a */
+static double
+three_point_angle (const graphene_point_t *a,
+ const graphene_point_t *b1,
+ const graphene_point_t *b2)
+{
+ graphene_vec2_t u;
+ graphene_vec2_t v;
+
+ graphene_vec2_init (&u, b1->x - a->x, b1->y - a->y);
+ graphene_vec2_init (&v, b2->x - a->x, b2->y - a->y);
+ graphene_vec2_normalize (&u, &u);
+ graphene_vec2_normalize (&v, &v);
+
+ return graphene_vec2_dot (&u, &v);
+}
+
+/* }}} */
+/* {{{ Misc. Bezier math */
+
+/* Given Bezier control points and a t value between 0 and 1,
+ * return new Bezier control points for two segments in left
+ * and right that are obtained by splitting the curve at the
+ * point for t.
+ *
+ * Note that the points in the right array are in returned in
+ * reverse order.
+ */
+static void
+split_bezier (graphene_point_t *points,
+ int length,
+ float t,
+ graphene_point_t *left,
+ int *left_pos,
+ graphene_point_t *right,
+ int *right_pos)
+{
+ if (length == 1)
+ {
+ left[*left_pos] = points[0];
+ (*left_pos)++;
+ right[*right_pos] = points[0];
+ (*right_pos)++;
+ }
+ else
+ {
+ graphene_point_t *newpoints;
+ int i;
+
+ newpoints = g_alloca (sizeof (graphene_point_t) * (length - 1));
+ for (i = 0; i < length - 1; i++)
+ {
+ if (i == 0)
+ {
+ left[*left_pos] = points[i];
+ (*left_pos)++;
+ }
+ if (i + 1 == length - 1)
+ {
+ right[*right_pos] = points[i + 1];
+ (*right_pos)++;
+ }
+ graphene_point_interpolate (&points[i], &points[i + 1], t, &newpoints[i]);
+ }
+ split_bezier (newpoints, length - 1, t, left, left_pos, right, right_pos);
+ }
+}
+
+static double
+projection_ratio (double t)
+{
+ double top, bottom;
+
+ if (t == 0 || t == 1)
+ return t;
+
+ top = pow (1 - t, 3),
+ bottom = pow (t, 3) + top;
+
+ return top / bottom;
+}
+
+static double
+abc_ratio (double t)
+{
+ double top, bottom;
+
+ if (t == 0 || t == 1)
+ return t;
+
+ bottom = pow (t, 3) + pow (1 - t, 3);
+ top = bottom - 1;
+
+ return fabs (top / bottom);
+}
+
+static void
+find_control_points (double t,
+ const graphene_point_t *A,
+ const graphene_point_t *B,
+ const graphene_point_t *C,
+ const graphene_point_t *S,
+ const graphene_point_t *E,
+ graphene_point_t *C1,
+ graphene_point_t *C2)
+{
+ double angle;
+ double dist;
+ double bc;
+ double de1;
+ double de2;
+ graphene_point_t c;
+ graphene_point_t t0, t1;
+ double tlength;
+ double dx, dy;
+ graphene_point_t e1, e2;
+ graphene_point_t v1, v2;
+
+ dist = graphene_point_distance (S, E, NULL, NULL);
+ angle = atan2 (E->y - S->y, E->x - S->x) - atan2 (B->y - S->y, B->x - S->x);
+ bc = (angle < 0 || angle > M_PI ? -1 : 1) * dist / 3;
+ de1 = t * bc;
+ de2 = (1 - t) * bc;
+
+ circle_through_points (S, B, E, &c);
+
+ t0.x = B->x - (B->y - c.y);
+ t0.y = B->y + (B->x - c.x);
+ t1.x = B->x + (B->y - c.y);
+ t1.y = B->y - (B->x - c.x);
+
+ tlength = graphene_point_distance (&t0, &t1, NULL, NULL);
+ dx = (t1.x - t0.x) / tlength;
+ dy = (t1.y - t0.y) / tlength;
+
+ e1.x = B->x + de1 * dx;
+ e1.y = B->y + de1 * dy;
+ e2.x = B->x - de2 * dx;
+ e2.y = B->y - de2 * dy;
+
+ v1.x = A->x + (e1.x - A->x) / (1 - t);
+ v1.y = A->y + (e1.y - A->y) / (1 - t);
+
+ v2.x = A->x + (e2.x - A->x) / t;
+ v2.y = A->y + (e2.y - A->y) / t;
+
+ C1->x = S->x + (v1.x - S->x) / t;
+ C1->y = S->y + (v1.y - S->y) / t;
+
+ C2->x = E->x + (v2.x - E->x) / (1 - t);
+ C2->y = E->y + (v2.y - E->y) / (1 - t);
+}
+
+/* Given points S, B, E, determine control
+ * points C1, C2 such that B lies on the
+ * Bezier segment given bY S, C1, C2, E.
+ */
+static void
+bezier_through (const graphene_point_t *S,
+ const graphene_point_t *B,
+ const graphene_point_t *E,
+ graphene_point_t *C1,
+ graphene_point_t *C2)
+{
+ double d1, d2, t;
+ double u, um, s;
+ graphene_point_t A, C;
+
+ d1 = graphene_point_distance (S, B, NULL, NULL);
+ d2 = graphene_point_distance (E, B, NULL, NULL);
+ t = d1 / (d1 + d2);
+
+ u = projection_ratio (t);
+ um = 1 - u;
+
+ C.x = u * S->x + um * E->x;
+ C.y = u * S->y + um * E->y;
+
+ s = abc_ratio (t);
+
+ A.x = B->x + (B->x - C.x) / s;
+ A.y = B->y + (B->y - C.y) / s;
+
+ find_control_points (t, &A, B, &C, S, E, C1, C2);
+}
+
+/* conics */
+
+static void
+get_conic_shoulder_point (const graphene_point_t p[3],
+ float w,
+ graphene_point_t *q)
+{
+ graphene_point_t m;
+
+ graphene_point_interpolate (&p[0], &p[2], 0.5, &m);
+ graphene_point_interpolate (&m, &p[1], w / (1 + w), q);
+}
+
+static void
+split_bezier3d_recurse (const graphene_point3d_t *p,
+ int l,
+ float t,
+ graphene_point3d_t *left,
+ graphene_point3d_t *right,
+ int *lpos,
+ int *rpos)
+{
+ if (l == 1)
+ {
+ left[*lpos] = p[0];
+ right[*rpos] = p[0];
+ }
+ else
+ {
+ graphene_point3d_t *np;
+ int i;
+
+ np = g_alloca (sizeof (graphene_point3d_t) * (l - 1));
+ for (i = 0; i < l - 1; i++)
+ {
+ if (i == 0)
+ {
+ left[*lpos] = p[i];
+ (*lpos)++;
+ }
+ if (i + 1 == l - 1)
+ {
+ right[*rpos] = p[i + 1];
+ (*rpos)--;
+ }
+ graphene_point3d_interpolate (&p[i], &p[i + 1], t, &np[i]);
+ }
+ split_bezier3d_recurse (np, l - 1, t, left, right, lpos, rpos);
+ }
+}
+
+static void
+split_bezier3d (const graphene_point3d_t *p,
+ int l,
+ float t,
+ graphene_point3d_t *left,
+ graphene_point3d_t *right)
+{
+ int lpos = 0;
+ int rpos = l - 1;
+ split_bezier3d_recurse (p, l, t, left, right, &lpos, &rpos);
+}
+
+static void
+split_conic (const graphene_point_t points[3], float weight,
+ float t,
+ graphene_point_t lp[3], float *lw,
+ graphene_point_t rp[3], float *rw)
+{
+ /* Given control points and weight for a rational quadratic
+ * Bezier and t, create two sets of the same that give the
+ * same curve as the original and split the curve at t.
+ */
+ graphene_point3d_t p[3];
+ graphene_point3d_t l[3], r[3];
+ int i;
+
+ /* do de Casteljau in homogeneous coordinates... */
+ for (i = 0; i < 3; i++)
+ {
+ p[i].x = points[i].x;
+ p[i].y = points[i].y;
+ p[i].z = 1;
+ }
+
+ p[1].x *= weight;
+ p[1].y *= weight;
+ p[1].z *= weight;
+
+ split_bezier3d (p, 3, t, l, r);
+
+ /* then project the control points down */
+ for (i = 0; i < 3; i++)
+ {
+ lp[i].x = l[i].x / l[i].z;
+ lp[i].y = l[i].y / l[i].z;
+ rp[i].x = r[i].x / r[i].z;
+ rp[i].y = r[i].y / r[i].z;
+ }
+
+ /* normalize the outer weights to be 1 by using
+ * the fact that weights w_i and c*w_i are equivalent
+ * for any nonzero constant c
+ */
+ for (i = 0; i < 3; i++)
+ {
+ l[i].z /= l[0].z;
+ r[i].z /= r[2].z;
+ }
+
+ /* normalize the inner weight to be 1 by using
+ * the fact that w_0*w_2/w_1^2 is a constant for
+ * all equivalent weights.
+ */
+ *lw = l[1].z / sqrt (l[2].z);
+ *rw = r[1].z / sqrt (r[0].z);
+}
+
+/* }}} */
+/* {{{ Utilities */
+
+static Segment *
+get_segment (CurveEditor *self,
+ int idx)
+{
+ idx = idx % (int)self->segments->len;
+ if (idx < 0)
+ idx += (int)self->segments->len;
+ return &g_array_index (self->segments, Segment, idx);
+}
+
+static void
+set_segment_start (CurveEditor *self,
+ int idx,
+ graphene_point_t *p)
+{
+ Segment *seg = get_segment (self, idx);
+ Segment *seg1 = get_segment (self, idx - 1);
+
+ seg->p[0] = *p;
+ seg1->p[3] = *p;
+}
+
+static const graphene_point_t *
+get_line_point (CurveEditor *self,
+ int idx)
+{
+ Segment *seg = get_segment (self, idx);
+ return &seg->p[0];
+}
+
+static graphene_point_t *
+get_left_control_point (CurveEditor *self,
+ int idx)
+{
+ Segment *seg = get_segment (self, idx - 1);
+ return &seg->p[2];
+}
+
+static graphene_point_t *
+get_right_control_point (CurveEditor *self,
+ int idx)
+{
+ Segment *seg = get_segment (self, idx);
+ return &seg->p[1];
+}
+
+static gboolean
+point_is_visible (CurveEditor *self,
+ int point,
+ int point1)
+{
+ Segment *seg;
+
+ if (!self->edit)
+ return FALSE;
+
+ seg = get_segment (self, point);
+ switch (point1)
+ {
+ case 0: /* point on curve */
+ return TRUE;
+
+ case 1:
+ if (self->edited_segment == point &&
+ seg->op != GSK_PATH_LINE)
+ return TRUE;
+ if (seg->op == GSK_PATH_CONIC &&
+ (self->edited_point == point + 1 ||
+ (self->edited_point == 0 && point + 1 == self->segments->len)))
+ return TRUE;
+ if (self->edited_point == point &&
+ (seg->op == GSK_PATH_CURVE || seg->op == GSK_PATH_CONIC))
+ return TRUE;
+ break;
+
+ case 2:
+ if (self->edited_segment == point &&
+ seg->op != GSK_PATH_LINE)
+ return TRUE;
+ if (seg->op == GSK_PATH_CURVE &&
+ (self->edited_point == point + 1 ||
+ (self->edited_point == 0 && point + 1 == self->segments->len)))
+ return TRUE;
+ break;
+
+ default:
+ g_assert_not_reached ();
+ }
+
+ return FALSE;
+}
+
+static void
+maintain_smoothness (CurveEditor *self,
+ int point)
+{
+ Segment *seg, *seg1;
+ const graphene_point_t *p, *p2;
+ graphene_point_t *c, *c2;
+ float d;
+
+ seg = get_segment (self, point);
+ seg1 = get_segment (self, point - 1);
+
+ if (seg->type == CUSP)
+ return;
+
+ if (seg->op == GSK_PATH_LINE && seg1->op == GSK_PATH_LINE)
+ return;
+
+ p = &seg->p[0];
+ c = &seg1->p[2];
+ c2 = &seg->p[1];
+
+ if (seg->op == GSK_PATH_CURVE && seg1->op == GSK_PATH_CURVE)
+ {
+ d = graphene_point_distance (c, p, NULL, NULL);
+ opposite_point (p, c2, d, c);
+ }
+ else if (seg->op == GSK_PATH_CURVE)
+ {
+ if (seg1->op == GSK_PATH_LINE)
+ p2 = &seg1->p[0];
+ else if (seg1->op == GSK_PATH_CONIC)
+ p2 = &seg1->p[1];
+ else
+ g_assert_not_reached ();
+ d = graphene_point_distance (c2, p, NULL, NULL);
+ opposite_point (p, p2, d, c2);
+ }
+ else if (seg1->op == GSK_PATH_CURVE)
+ {
+ if (seg->op == GSK_PATH_LINE)
+ p2 = &seg->p[3];
+ else if (seg->op == GSK_PATH_CONIC)
+ p2 = &seg->p[1];
+ else
+ g_assert_not_reached ();
+ d = graphene_point_distance (c, p, NULL, NULL);
+ opposite_point (p, p2, d, c);
+ }
+ else if (seg->op == GSK_PATH_CONIC && seg1->op == GSK_PATH_CONIC)
+ {
+ graphene_point_t h, a, b;
+
+ h.x = seg->p[0].x + seg->p[1].x - seg1->p[1].x;
+ h.y = seg->p[0].y + seg->p[1].y - seg1->p[1].y;
+ line_intersection (&seg->p[0], &h, &seg1->p[0], &seg1->p[1], &a);
+ line_intersection (&seg->p[0], &h, &seg->p[1], &seg->p[3], &b);
+
+ seg1->p[1] = a;
+ seg->p[1] = b;
+ }
+}
+
+static void
+maintain_symmetry (CurveEditor *self,
+ int point)
+{
+ Segment *seg, *seg1;
+ const graphene_point_t *p;
+ graphene_point_t *c, *c2;
+ double l1, l2, l;
+
+ seg = get_segment (self, point);
+ seg1 = get_segment (self, point - 1);
+
+ if (seg->type != SYMMETRIC)
+ return;
+
+ if (seg->op != GSK_PATH_CURVE || seg1->op != GSK_PATH_CURVE)
+ return;
+
+ p = &seg->p[0];
+ c = &seg1->p[2];
+ c2 = &seg->p[1];
+
+ l1 = graphene_point_distance (p, c, NULL, NULL);
+ l2 = graphene_point_distance (p, c2, NULL, NULL);
+
+ if (l1 != l2)
+ {
+ l = (l1 + l2) / 2;
+
+ scale_point (p, c, l, c);
+ scale_point (p, c2, l, c2);
+ }
+}
+
+/* Make the line through the control points perpendicular
+ * to the line bisecting the angle between neighboring
+ * points, and make the lengths 1/3 of the distance to
+ * the corresponding neighboring points.
+ */
+static void
+update_automatic (CurveEditor *self,
+ int point)
+{
+ Segment *seg;
+ const graphene_point_t *p, *p1, *p2;
+ double l1, l2;
+ graphene_point_t a;
+ graphene_point_t *c1, *c2;
+
+ seg = get_segment (self, point);
+
+ if (seg->type != AUTO)
+ return;
+
+ if (seg->op != GSK_PATH_CURVE || get_segment (self, point - 1)->op != GSK_PATH_CURVE)
+ return;
+
+ p = get_line_point (self, point);
+ c1 = get_left_control_point (self, point);
+ c2 = get_right_control_point (self, point);
+
+ p1 = get_line_point (self, point - 1);
+ p2 = get_line_point (self, point + 1);
+
+ l1 = graphene_point_distance (p, p1, NULL, NULL);
+ l2 = graphene_point_distance (p, p2, NULL, NULL);
+
+ a.x = p2->x + (p->x - p1->x);
+ a.y = p2->y + (p->y - p1->y);
+
+ scale_point (p, &a, l2/3, c2);
+ opposite_point (p, &a, l1/3, c1);
+}
+
+static void
+maintain_automatic (CurveEditor *self,
+ int point)
+{
+ if (get_segment (self, point)->op != GSK_PATH_CURVE ||
+ get_segment (self, point - 1)->op != GSK_PATH_CURVE)
+ return;
+
+ update_automatic (self, point);
+ update_automatic (self, point - 1);
+ update_automatic (self, point + 1);
+}
+
+static void
+maintain_conic (CurveEditor *self,
+ int idx)
+{
+ Segment *seg = get_segment (self, idx);
+ graphene_point_t p[3];
+
+ if (seg->op != GSK_PATH_CONIC)
+ return;
+
+ p[0] = seg->p[0];
+ p[1] = seg->p[1];
+ p[2] = seg->p[3];
+
+ get_conic_shoulder_point (p, seg->weight, &seg->p[2]);
+}
+
+/* Check if the points arount point currently satisfy
+ * smoothness conditions. Set PointData.type accordingly.
+ */
+static void
+check_smoothness (CurveEditor *self,
+ int point)
+{
+ GskPathOperation op, op1;
+ const graphene_point_t *p, *p1, *p2;
+ Segment *seg, *seg1;
+
+ seg = get_segment (self, point);
+ seg1 = get_segment (self, point - 1);
+ p = get_line_point (self, point);
+
+ op = seg->op;
+ op1 = seg1->op;
+
+ if (op == GSK_PATH_CURVE)
+ p2 = get_right_control_point (self, point);
+ else if (op == GSK_PATH_LINE)
+ p2 = get_line_point (self, point + 1);
+ else
+ p2 = NULL;
+
+ if (op1 == GSK_PATH_CURVE)
+ p1 = get_left_control_point (self, point);
+ else if (op1 == GSK_PATH_LINE)
+ p1 = get_line_point (self, point - 1);
+ else
+ p1 = NULL;
+
+ if (!p1 || !p2 || !collinear (p, p1, p2))
+ seg->type = CUSP;
+ else
+ seg->type = SMOOTH;
+}
+
+static void
+insert_point (CurveEditor *self,
+ int point,
+ double pos)
+{
+ Segment *seg, *seg1, *seg2;
+ Segment ns = { 0, };;
+
+ seg = get_segment (self, point);
+ if (seg->op == GSK_PATH_MOVE)
+ return;
+
+ g_array_insert_val (self->segments, point + 1, ns);
+
+ seg = get_segment (self, point);
+ seg1 = get_segment (self, point + 1);
+ seg2 = get_segment (self, point + 2);
+
+ seg1->type = SMOOTH;
+ seg1->hovered = -1;
+ seg1->dragged = -1;
+
+ switch (seg->op)
+ {
+ case GSK_PATH_LINE:
+ seg1->op = GSK_PATH_LINE;
+
+ graphene_point_interpolate (&seg->p[0], &seg->p[3], pos, &seg1->p[0]);
+ seg->p[3] = seg->p[0];
+ seg1->p[3] = seg2->p[0];
+ break;
+
+ case GSK_PATH_CURVE:
+ {
+ graphene_point_t left[4];
+ graphene_point_t right[4];
+ int left_pos = 0;
+ int right_pos = 0;
+
+ seg1->op = GSK_PATH_CURVE;
+
+ split_bezier (seg->p, 4, pos, left, &left_pos, right, &right_pos);
+
+ seg->p[0] = left[0];
+ seg->p[1] = left[1];
+ seg->p[2] = left[2];
+ seg->p[3] = left[3];
+ seg1->p[0] = right[3];
+ seg1->p[1] = right[2];
+ seg1->p[2] = right[1];
+ seg1->p[3] = right[0];
+ }
+ break;
+
+ case GSK_PATH_CONIC:
+ {
+ graphene_point_t points[3];
+ graphene_point_t left[3];
+ graphene_point_t right[3];
+ float lw, rw;
+
+ seg1->op = GSK_PATH_CONIC;
+
+ points[0] = seg->p[0];
+ points[1] = seg->p[1];
+ points[2] = seg->p[3];
+ split_conic (points, seg->weight, pos, left, &lw, right, &rw);
+
+ seg->p[0] = left[0];
+ seg->p[1] = left[1];
+ seg->p[3] = left[2];
+ seg1->p[0] = right[0];
+ seg1->p[1] = right[1];
+ seg1->p[3] = right[2];
+
+ seg->weight = lw;
+ seg1->weight = rw;
+
+ get_conic_shoulder_point (seg->p, seg->weight, &seg->p[2]);
+ get_conic_shoulder_point (seg1->p, seg1->weight, &seg1->p[2]);
+ }
+ break;
+
+ case GSK_PATH_MOVE:
+ case GSK_PATH_CLOSE:
+ default:
+ g_assert_not_reached ();
+ break;
+ }
+
+ maintain_smoothness (self, point + 1);
+ maintain_automatic (self, point + 1);
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+remove_point (CurveEditor *self,
+ int point)
+{
+ Segment *seg;
+ graphene_point_t c, p;
+
+ seg = get_segment (self, point);
+ c = seg->p[2];
+ p = seg->p[3];
+
+ g_array_remove_index (self->segments, point);
+
+ seg = get_segment (self, point - 1);
+ seg->p[2] = c;
+ seg->p[3] = p;
+
+ maintain_smoothness (self, point);
+ maintain_automatic (self, point);
+}
+
+/* }}} */
+/* {{{ GskPath helpers */
+
+static void
+curve_editor_add_segment (CurveEditor *self,
+ GskPathBuilder *builder,
+ int point)
+{
+ Segment *seg;
+
+ seg = get_segment (self, point);
+
+ gsk_path_builder_move_to (builder, seg->p[0].x, seg->p[0].y);
+
+ switch (seg->op)
+ {
+ case GSK_PATH_LINE:
+ gsk_path_builder_line_to (builder, seg->p[3].x, seg->p[3].y);
+ break;
+
+ case GSK_PATH_CURVE:
+ gsk_path_builder_curve_to (builder,
+ seg->p[1].x, seg->p[1].y,
+ seg->p[2].x, seg->p[2].y,
+ seg->p[3].x, seg->p[3].y);
+ break;
+
+ case GSK_PATH_CONIC:
+ gsk_path_builder_conic_to (builder,
+ seg->p[1].x, seg->p[1].y,
+ seg->p[3].x, seg->p[3].y,
+ seg->weight);
+ break;
+
+ case GSK_PATH_MOVE:
+ case GSK_PATH_CLOSE:
+ default:
+ break;
+ }
+}
+
+static void
+curve_editor_add_path (CurveEditor *self,
+ GskPathBuilder *builder)
+{
+ int i;
+
+ for (i = 0; i < self->segments->len; i++)
+ {
+ Segment *seg = get_segment (self, i);
+
+ if (i == 0)
+ gsk_path_builder_move_to (builder, seg->p[0].x, seg->p[0].y);
+
+ switch (seg->op)
+ {
+ case GSK_PATH_MOVE:
+ gsk_path_builder_move_to (builder, seg->p[3].x, seg->p[3].y);
+ break;
+
+ case GSK_PATH_LINE:
+ gsk_path_builder_line_to (builder, seg->p[3].x, seg->p[3].y);
+ break;
+
+ case GSK_PATH_CURVE:
+ gsk_path_builder_curve_to (builder,
+ seg->p[1].x, seg->p[1].y,
+ seg->p[2].x, seg->p[2].y,
+ seg->p[3].x, seg->p[3].y);
+ break;
+
+ case GSK_PATH_CONIC:
+ gsk_path_builder_conic_to (builder,
+ seg->p[1].x, seg->p[1].y,
+ seg->p[3].x, seg->p[3].y,
+ seg->weight);
+ break;
+
+ case GSK_PATH_CLOSE:
+ default:
+ g_assert_not_reached ();
+ }
+ }
+
+ gsk_path_builder_close (builder);
+}
+
+static gboolean
+find_closest_segment (CurveEditor *self,
+ graphene_point_t *point,
+ float threshold,
+ graphene_point_t *p,
+ int *segment,
+ float *pos)
+{
+ graphene_point_t pp;
+ float t;
+ int seg;
+ gboolean found = FALSE;
+ int i;
+
+ for (i = 0; i < self->segments->len; i++)
+ {
+ GskPathBuilder *builder;
+ GskPath *path;
+ GskPathMeasure *measure;
+ float t1;
+ graphene_point_t pp1;
+
+ builder = gsk_path_builder_new ();
+ curve_editor_add_segment (self, builder, i);
+ path = gsk_path_builder_free_to_path (builder);
+ measure = gsk_path_measure_new (path);
+
+ if (gsk_path_measure_get_closest_point_full (measure, point, threshold, &threshold, &pp1, &t1, NULL))
+ {
+ seg = i;
+ t = t1 / gsk_path_measure_get_length (measure);
+ pp = pp1;
+ found = TRUE;
+ }
+
+ gsk_path_measure_unref (measure);
+ gsk_path_unref (path);
+ }
+
+ if (found)
+ {
+ if (segment)
+ *segment = seg;
+ if (pos)
+ *pos = t;
+ if (p)
+ *p = pp;
+ }
+
+ return found;
+}
+
+/* }}} */
+/* {{{ Drag implementation */
+
+static void
+drag_begin (GtkGestureDrag *gesture,
+ double start_x,
+ double start_y,
+ CurveEditor *self)
+{
+ int i, j;
+ graphene_point_t p = GRAPHENE_POINT_INIT (start_x, start_y);
+ float t;
+ int idx;
+
+ if (!self->edit)
+ return;
+
+ for (i = 0; i < self->segments->len; i++)
+ {
+ Segment *seg = get_segment (self, i);
+
+ for (j = 0; j < 3; j++)
+ {
+ if (graphene_point_distance (&seg->p[j], &p, NULL, NULL) < CLICK_RADIUS)
+ {
+ if (point_is_visible (self, i, j))
+ {
+ self->dragged = i;
+ seg->dragged = j;
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+ }
+ return;
+ }
+ }
+ }
+
+ if (find_closest_segment (self, &p, CLICK_RADIUS, NULL, &idx, &t))
+ {
+ /* Can't bend a straight line */
+ get_segment (self, idx)->op = GSK_PATH_CURVE;
+ self->molded = idx;
+ return;
+ }
+
+ gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_DENIED);
+}
+
+static void
+drag_line_point (CurveEditor *self,
+ double x,
+ double y)
+{
+ /* dragged point is on curve */
+ Segment *seg, *seg1, *seg2, *seg11;
+ const graphene_point_t *d, *p;
+ graphene_point_t *c;
+ float l1, l2, dx, dy;
+
+ seg = get_segment (self, self->dragged);
+ d = get_line_point (self, self->dragged);
+
+ /* before moving the point, record the distances to its neighbors, since
+ * we may want to preserve those
+ */
+ l1 = graphene_point_distance (d, get_left_control_point (self, self->dragged), NULL, NULL);
+ l2 = graphene_point_distance (d, get_right_control_point (self, self->dragged), NULL, NULL);
+
+ dx = x - d->x;
+ dy = y - d->y;
+
+ /* first move the point itself */
+ set_segment_start (self, self->dragged, &GRAPHENE_POINT_INIT (x, y));
+
+ /* adjust control points as needed */
+ seg1 = get_segment (self, self->dragged - 1);
+ seg2 = get_segment (self, self->dragged + 1);
+
+ if (seg1->op == GSK_PATH_LINE)
+ {
+ /* the other endpoint of the line */
+ p = get_line_point (self, self->dragged - 1);
+ c = get_right_control_point (self, self->dragged);
+
+ if (seg->op == GSK_PATH_CURVE && seg->type != CUSP)
+ {
+ opposite_point (d, p, l2, c);
+ }
+ else if (seg->op == GSK_PATH_CONIC && seg->type != CUSP)
+ {
+ graphene_point_t u;
+ line_intersection (&seg1->p[0], &seg1->p[3], &seg->p[3], &seg->p[1], &u);
+ if (u.x != NAN)
+ seg->p[1] = u;
+ else
+ {
+ seg->p[1].x += dx;
+ seg->p[1].y += dy;
+ }
+
+ maintain_conic (self, self->dragged);
+ }
+ else
+ {
+ c->x += dx;
+ c->y += dy;
+ }
+
+ /* always move the other control point along */
+ c = get_left_control_point (self, self->dragged);
+ c->x += dx;
+ c->y += dy;
+
+ /* handle the far end of the line */
+ seg11 = get_segment (self, self->dragged - 2);
+
+ if (seg11->op == GSK_PATH_CURVE && seg1->type != CUSP)
+ {
+ double l;
+ const graphene_point_t *p2;
+ graphene_point_t *c2;
+
+ p2 = get_line_point (self, self->dragged - 1);
+ c2 = get_left_control_point (self, self->dragged - 1);
+ /* adjust the control point before the line segment */
+ l = graphene_point_distance (c2, p2, NULL, NULL);
+ opposite_point (p2, d, l, c2);
+ }
+ else if (seg11->op == GSK_PATH_CONIC && seg1->type != CUSP)
+ {
+ graphene_point_t u;
+ line_intersection (&seg11->p[0], &seg11->p[1], &seg1->p[3], &seg1->p[0], &u);
+ if (u.x != NAN)
+ seg11->p[1] = u;
+
+ maintain_conic (self, self->dragged - 2);
+ }
+ }
+
+ if (seg->op == GSK_PATH_LINE)
+ {
+ /* the other endpoint of the line */
+ p = get_line_point (self, self->dragged + 1);
+ c = get_left_control_point (self, self->dragged);
+
+ if (seg1->op == GSK_PATH_CURVE && seg->type != CUSP)
+ {
+ /* adjust the control point before the line segment */
+ opposite_point (d, p, l1, c);
+ }
+ else if (seg1->op == GSK_PATH_CONIC && seg->type != CUSP)
+ {
+ graphene_point_t u;
+ line_intersection (&seg1->p[0], &seg1->p[1], &seg->p[0], &seg->p[3], &u);
+ if (u.x != NAN)
+ seg1->p[1] = u;
+ else
+ {
+ seg1->p[1].x += dx;
+ seg1->p[1].y += dy;
+ }
+
+ maintain_conic (self, self->dragged);
+ }
+ else if (seg1->op == GSK_PATH_CURVE)
+ {
+ c->x += dx;
+ c->y += dy;
+ }
+
+ /* always move the other control point along */
+ c = get_right_control_point (self, self->dragged);
+ c->x += dx;
+ c->x += dy;
+
+ /* handle the other end of the line */
+ if (seg2->op == GSK_PATH_CURVE && seg2->type != CUSP)
+ {
+ double l;
+
+ /* adjust the control point after the line segment */
+ c = get_right_control_point (self, self->dragged + 1);
+ l = graphene_point_distance (c, p, NULL, NULL);
+ opposite_point (p, d, l, c);
+ }
+ else if (seg2->op == GSK_PATH_CONIC && seg2->type != CUSP)
+ {
+ graphene_point_t u;
+ line_intersection (&seg->p[0], &seg->p[3], &seg2->p[1], &seg2->p[3], &u);
+ if (u.x != NAN)
+ seg2->p[1] = u;
+
+ maintain_conic (self, self->dragged + 1);
+ }
+ }
+
+ if (seg1->op != GSK_PATH_LINE && seg->op != GSK_PATH_LINE)
+ {
+ if (seg1->op == GSK_PATH_CURVE)
+ {
+ c = &seg1->p[2];
+ c->x += dx;
+ c->y += dy;
+ }
+ else if (seg1->op == GSK_PATH_CONIC && seg->type != CUSP)
+ {
+ graphene_point_t a, b;
+
+ a.x = seg1->p[1].x + dx;
+ a.y = seg1->p[1].y + dy;
+ line_intersection (&seg->p[0], &a, &seg1->p[0], &seg1->p[1], &b);
+ seg1->p[1] = b;
+ }
+
+ if (seg->op == GSK_PATH_CURVE)
+ {
+ c = &seg->p[1];
+ c->x += dx;
+ c->y += dy;
+ }
+ else if (seg->op == GSK_PATH_CONIC && seg->type != CUSP)
+ {
+ graphene_point_t a, b;
+
+ a.x = seg->p[1].x + dx;
+ a.y = seg->p[1].y + dy;
+ line_intersection (&seg->p[3], &seg->p[1], &a, &seg->p[0], &b);
+ seg->p[1] = b;
+ }
+ }
+
+ maintain_smoothness (self, self->dragged);
+ maintain_automatic (self, self->dragged);
+ maintain_conic (self, self->dragged);
+ maintain_conic (self, self->dragged - 1);
+}
+
+static void
+drag_conic_point (CurveEditor *self,
+ float x,
+ float y)
+{
+ Segment *seg, *seg1, *seg2;
+ graphene_point_t *d, *c1;
+ float l;
+
+ seg = get_segment (self, self->dragged);
+ g_assert (seg->op == GSK_PATH_CONIC);
+ d = &seg->p[seg->dragged];
+
+ seg1 = get_segment (self, self->dragged + 1);
+ seg2 = get_segment (self, self->dragged - 1);
+
+ if (seg->dragged == 1)
+ {
+ if (seg->type != CUSP && seg2->op == GSK_PATH_LINE)
+ {
+ /* control point must be on the line of seg2 */
+
+ if (seg1->type != CUSP && seg1->op == GSK_PATH_LINE)
+ {
+ graphene_point_t c;
+
+ line_intersection (&seg1->p[0], &seg1->p[3], &seg2->p[3], &seg2->p[0], &c);
+ if (c.x != NAN)
+ *d = c; /* unmoveable */
+ else
+ {
+ closest_point (&GRAPHENE_POINT_INIT (x, y), &seg1->p[0], &seg1->p[3], &c);
+ *d = c;
+ }
+ }
+ else
+ {
+ graphene_point_t c;
+
+ closest_point (&GRAPHENE_POINT_INIT (x, y), &seg2->p[0], &seg2->p[3], &c);
+ *d = c;
+
+ if (seg1->type != CUSP)
+ {
+ l = graphene_point_distance (&seg1->p[0], &seg1->p[1], NULL, NULL);
+ opposite_point (&seg1->p[0], d, l, &seg1->p[1]);
+ }
+ }
+ }
+ else if (seg1->type != CUSP && seg1->op == GSK_PATH_LINE)
+ {
+ graphene_point_t c;
+
+ closest_point (&GRAPHENE_POINT_INIT (x, y), &seg1->p[0], &seg1->p[3], &c);
+ *d = c;
+
+ if (seg2->type != CUSP)
+ {
+ if (seg2->op == GSK_PATH_CURVE)
+ c1 = &seg2->p[2];
+ else if (seg2->op == GSK_PATH_CONIC)
+ c1 = &seg2->p[1];
+ else
+ g_assert_not_reached ();
+ l = graphene_point_distance (&seg2->p[3], c1, NULL, NULL);
+ opposite_point (&seg2->p[3], d, l, c1);
+ }
+ }
+ else
+ {
+ /* unconstrained */
+ d->x = x;
+ d->y = y;
+
+ if (seg1->type != CUSP)
+ {
+ l = graphene_point_distance (&seg1->p[0], &seg1->p[1], NULL, NULL);
+ opposite_point (&seg1->p[0], d, l, &seg1->p[1]);
+ }
+
+ if (seg2->type != CUSP)
+ {
+ if (seg2->op == GSK_PATH_CURVE)
+ c1 = &seg2->p[2];
+ else if (seg2->op == GSK_PATH_CONIC)
+ c1 = &seg2->p[1];
+ else
+ g_assert_not_reached ();
+ l = graphene_point_distance (&seg2->p[3], c1, NULL, NULL);
+ opposite_point (&seg2->p[3], d, l, c1);
+ }
+ }
+ }
+ else if (seg->dragged == 2)
+ {
+ /* dragging the shoulder point */
+ graphene_point_t m;
+ float t;
+
+ graphene_point_interpolate (&seg->p[0], &seg->p[3], 0.5, &m);
+ find_point_on_line (&m, &seg->p[1], &GRAPHENE_POINT_INIT (x, y), &t);
+ t = CLAMP (t, 0, 0.9);
+ seg->weight = - t / (t - 1);
+ }
+
+ maintain_conic (self, self->dragged);
+}
+
+static void
+drag_control_point (CurveEditor *self,
+ float x,
+ float y)
+{
+ /* dragged point is a control point */
+ Segment *seg, *seg1;
+ const graphene_point_t *p, *p1;
+ graphene_point_t *c, *d;
+ PointType type;
+
+ seg = get_segment (self, self->dragged);
+ g_assert (seg->op == GSK_PATH_CURVE);
+ d = &seg->p[seg->dragged];
+
+ if (seg->dragged == 2)
+ {
+ seg1 = get_segment (self, self->dragged + 1);
+ p = &seg1->p[0];
+ c = &seg1->p[1];
+ type = seg1->type;
+ p1 = get_line_point (self, self->dragged + 2);
+ }
+ else if (seg->dragged == 1)
+ {
+ seg1 = get_segment (self, self->dragged - 1);
+ if (seg1->op == GSK_PATH_CONIC)
+ c = &seg1->p[1];
+ else
+ c = &seg1->p[2];
+ p = &seg->p[0];
+ type = seg->type;
+ p1 = &seg1->p[0];
+ }
+ else
+ g_assert_not_reached ();
+
+ if (type != CUSP)
+ {
+ if (seg1->op == GSK_PATH_CURVE)
+ {
+ double l;
+
+ /* first move the point itself */
+ d->x = x;
+ d->y = y;
+
+ /* then adjust the other control point */
+ if (type == SYMMETRIC)
+ l = graphene_point_distance (d, p, NULL, NULL);
+ else
+ l = graphene_point_distance (c, p, NULL, NULL);
+
+ opposite_point (p, d, l, c);
+ }
+ else if (seg1->op == GSK_PATH_CONIC)
+ {
+ graphene_point_t u;
+
+ d->x = x;
+ d->y = y;
+ line_intersection (p1, c, p, d, &u);
+ *c = u;
+
+ maintain_conic (self, self->dragged - 1);
+ maintain_conic (self, self->dragged + 1);
+ }
+ else if (seg1->op == GSK_PATH_LINE)
+ {
+ graphene_point_t m = GRAPHENE_POINT_INIT (x, y);
+ closest_point (&m, p, p1, d);
+ }
+ else
+ {
+ d->x = x;
+ d->y = y;
+ }
+ }
+ else
+ {
+ d->x = x;
+ d->y = y;
+ }
+}
+
+static void
+drag_point (CurveEditor *self,
+ double x,
+ double y)
+{
+ Segment *seg = get_segment (self, self->dragged);
+
+ if (seg->dragged == 0)
+ drag_line_point (self, x, y);
+ else if (seg->op == GSK_PATH_CONIC)
+ drag_conic_point (self, x, y);
+ else
+ drag_control_point (self, x, y);
+}
+
+static void
+drag_curve (CurveEditor *self,
+ double x,
+ double y)
+{
+ graphene_point_t *S, *E;
+ graphene_point_t B, C1, C2;
+ double l;
+ Segment *seg, *seg1, *seg2;
+
+ seg = get_segment (self, self->molded);
+ seg1 = get_segment (self, self->molded + 1);
+ seg2 = get_segment (self, self->molded - 1);
+
+ if (seg->op == GSK_PATH_CONIC)
+ {
+ /* FIXME */
+ return;
+ }
+
+ S = &seg->p[0];
+ B = GRAPHENE_POINT_INIT (x, y);
+ E = &seg->p[3];
+
+ bezier_through (S, &B, E, &C1, &C2);
+
+ seg->p[1] = C1;
+ seg->p[2] = C2;
+
+ /* When the neighboring segments are lines, we can't actually
+ * use C1 and C2 as-is, since we need control points to lie
+ * on the line. So we just use their distance. This makes our
+ * point B not quite match anymore, but we're overconstrained.
+ */
+ if (seg2->op == GSK_PATH_LINE)
+ {
+ l = graphene_point_distance (&seg->p[3], &C1, NULL, NULL);
+ if (three_point_angle (&seg2->p[3], &seg2->p[0], &B) > 0)
+ scale_point (&seg2->p[3], &seg2->p[0], l, &seg->p[1]);
+ else
+ opposite_point (&seg2->p[3], &seg2->p[0], l, &seg->p[1]);
+ }
+
+ if (seg1->op == GSK_PATH_LINE)
+ {
+ l = graphene_point_distance (&seg->p[0], &C2, NULL, NULL);
+ if (three_point_angle (&seg1->p[0], &seg1->p[3], &B) > 0)
+ scale_point (&seg1->p[0], &seg1->p[3], l, &seg->p[2]);
+ else
+ opposite_point (&seg1->p[0], &seg1->p[3], l, &seg->p[2]);
+ }
+
+ /* Maintain smoothness and symmetry */
+ if (seg->type != CUSP)
+ {
+ if (seg->type == SYMMETRIC)
+ l = graphene_point_distance (&seg->p[0], &seg->p[1], NULL, NULL);
+ else
+ l = graphene_point_distance (&seg->p[0], &seg2->p[2], NULL, NULL);
+ opposite_point (&seg->p[0], &seg->p[1], l, &seg2->p[2]);
+ }
+
+ if (seg1->type != CUSP)
+ {
+ if (seg1->type == SYMMETRIC)
+ l = graphene_point_distance (&seg->p[3], &seg->p[2], NULL, NULL);
+ else
+ l = graphene_point_distance (&seg->p[3], &seg1->p[1], NULL, NULL);
+ opposite_point (&seg->p[3], &seg->p[2], l, &seg1->p[1]);
+ }
+}
+
+static void
+drag_update (GtkGestureDrag *gesture,
+ double offset_x,
+ double offset_y,
+ CurveEditor *self)
+{
+ double x, y;
+
+ gtk_gesture_drag_get_start_point (gesture, &x, &y);
+
+ x += offset_x;
+ y += offset_y;
+
+ if (self->dragged != -1)
+ {
+ gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_CLAIMED);
+ drag_point (self, x, y);
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+ }
+ else if (self->molded != -1)
+ {
+ gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_CLAIMED);
+ drag_curve (self, x, y);
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+ }
+}
+
+static void
+drag_end (GtkGestureDrag *gesture,
+ double offset_x,
+ double offset_y,
+ CurveEditor *self)
+{
+ drag_update (gesture, offset_x, offset_y, self);
+ self->dragged = -1;
+ self->molded = -1;
+}
+
+/* }}} */
+/* {{{ Action callbacks */
+
+static void
+set_point_type (GSimpleAction *action,
+ GVariant *value,
+ gpointer data)
+{
+ CurveEditor *self = CURVE_EDITOR (data);
+
+ get_segment (self, self->context)->type = point_type_from_string (g_variant_get_string (value, NULL));
+
+ maintain_smoothness (self, self->context);
+ maintain_symmetry (self, self->context);
+ maintain_automatic (self, self->context);
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+set_operation (GSimpleAction *action,
+ GVariant *value,
+ gpointer data)
+{
+ CurveEditor *self = CURVE_EDITOR (data);
+ Segment *seg = get_segment (self, self->context);
+
+ seg->op = op_from_string (g_variant_get_string (value, NULL));
+
+ if (seg->op == GSK_PATH_CONIC && seg->weight == 0)
+ seg->weight = 1;
+
+ maintain_conic (self, self->context);
+
+ maintain_smoothness (self, self->context);
+ maintain_smoothness (self, self->context + 1);
+ maintain_symmetry (self, self->context);
+ maintain_symmetry (self, self->context + 1);
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+insert_new_point (GSimpleAction *action,
+ GVariant *value,
+ gpointer data)
+{
+ CurveEditor *self = CURVE_EDITOR (data);
+
+ insert_point (self, self->context, self->context_pos);
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+remove_current_point (GSimpleAction *action,
+ GVariant *value,
+ gpointer data)
+{
+ CurveEditor *self = CURVE_EDITOR (data);
+
+ remove_point (self, self->context);
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+toggle_edit_point (GSimpleAction *action,
+ GVariant *value,
+ gpointer data)
+{
+ CurveEditor *self = CURVE_EDITOR (data);
+
+ if (self->edited_point == self->context)
+ self->edited_point = -1;
+ else
+ {
+ self->edited_point = self->context;
+ self->edited_segment = -1;
+ }
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+toggle_edit_segment (GSimpleAction *action,
+ GVariant *value,
+ gpointer data)
+{
+ CurveEditor *self = CURVE_EDITOR (data);
+
+ if (self->edited_segment == self->context)
+ self->edited_segment = -1;
+ else
+ {
+ self->edited_segment = self->context;
+ self->edited_point = -1;
+ }
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+reset_weight (GSimpleAction *action,
+ GVariant *value,
+ gpointer data)
+{
+ CurveEditor *self = CURVE_EDITOR (data);
+ Segment *seg = get_segment (self, self->context);
+
+ seg->weight = 1;
+ maintain_conic (self, self->context);
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+/* }}} */
+/* {{{ Event handlers */
+
+static void
+pressed (GtkGestureClick *gesture,
+ int n_press,
+ double x,
+ double y,
+ CurveEditor *self)
+{
+ graphene_point_t m = GRAPHENE_POINT_INIT (x, y);
+ int i;
+ int button = gtk_gesture_single_get_current_button (GTK_GESTURE_SINGLE (gesture));
+ float t;
+
+ if (!self->edit)
+ return;
+
+ if (button == GDK_BUTTON_SECONDARY)
+ {
+ for (i = 0; i < self->segments->len; i++)
+ {
+ Segment *seg = get_segment (self, i);
+ const graphene_point_t *p = get_line_point (self, i);
+
+ if (graphene_point_distance (p, &m, NULL, NULL) < CLICK_RADIUS)
+ {
+ GAction *action;
+
+ self->context = i;
+
+ action = g_action_map_lookup_action (self->actions, "set-segment-type");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), FALSE);
+
+ action = g_action_map_lookup_action (self->actions, "add-point");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), FALSE);
+
+ action = g_action_map_lookup_action (self->actions, "remove-point");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), TRUE);
+
+ action = g_action_map_lookup_action (self->actions, "reset-weight");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), FALSE);
+
+ action = g_action_map_lookup_action (self->actions, "set-point-type");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), TRUE);
+ g_simple_action_set_state (G_SIMPLE_ACTION (action), g_variant_new_string
(point_type_to_string (seg->type)));
+
+ action = g_action_map_lookup_action (self->actions, "edit-point");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), TRUE);
+ g_simple_action_set_state (G_SIMPLE_ACTION (action), g_variant_new_boolean (self->edited_point
== i));
+
+ action = g_action_map_lookup_action (self->actions, "edit-segment");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), FALSE);
+
+ gtk_popover_set_pointing_to (GTK_POPOVER (self->menu),
+ &(const GdkRectangle){ x, y, 1, 1 });
+ gtk_popover_popup (GTK_POPOVER (self->menu));
+ return;
+ }
+ }
+
+ if (find_closest_segment (self, &m, CLICK_RADIUS, NULL, &i, &t))
+ {
+ GAction *action;
+
+ self->context = i;
+ self->context_pos = t;
+
+ action = g_action_map_lookup_action (self->actions, "set-point-type");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), FALSE);
+
+ action = g_action_map_lookup_action (self->actions, "edit-point");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), FALSE);
+
+ action = g_action_map_lookup_action (self->actions, "remove-point");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), FALSE);
+
+ action = g_action_map_lookup_action (self->actions, "add-point");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), TRUE);
+
+ action = g_action_map_lookup_action (self->actions, "edit-segment");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), TRUE);
+ g_simple_action_set_state (G_SIMPLE_ACTION (action), g_variant_new_boolean (self->edited_segment
== i));
+
+ action = g_action_map_lookup_action (self->actions, "reset-weight");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action),
+ get_segment (self, i)->op == GSK_PATH_CONIC);
+
+ action = g_action_map_lookup_action (self->actions, "set-segment-type");
+ g_simple_action_set_enabled (G_SIMPLE_ACTION (action), TRUE);
+ g_simple_action_set_state (G_SIMPLE_ACTION (action), g_variant_new_string (op_to_string
(get_segment (self, i)->op)));
+
+ gtk_popover_set_pointing_to (GTK_POPOVER (self->menu),
+ &(const GdkRectangle){ x, y, 1, 1 });
+ gtk_popover_popup (GTK_POPOVER (self->menu));
+ return;
+ }
+ }
+}
+
+static void
+released (GtkGestureClick *gesture,
+ int n_press,
+ double x,
+ double y,
+ CurveEditor *self)
+{
+ graphene_point_t m = GRAPHENE_POINT_INIT (x, y);
+ int button = gtk_gesture_single_get_current_button (GTK_GESTURE_SINGLE (gesture));
+ int i;
+
+ if (!self->edit)
+ return;
+
+ for (i = 0; i < self->segments->len; i++)
+ {
+ const graphene_point_t *p = get_line_point (self, i);
+
+ if (graphene_point_distance (p, &m, NULL, NULL) < CLICK_RADIUS)
+ {
+ if (button == GDK_BUTTON_PRIMARY)
+ {
+ if (self->edited_point == i)
+ self->edited_point = -1;
+ else
+ {
+ self->edited_point = i;
+ self->edited_segment = -1;
+ }
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+ return;
+ }
+ }
+ }
+
+ if (button == GDK_BUTTON_PRIMARY)
+ {
+ float t;
+ int point;
+
+ if (find_closest_segment (self, &m, CLICK_RADIUS, NULL, &point, &t))
+ {
+ self->dragged = -1;
+ self->molded = -1;
+ insert_point (self, point, t);
+ }
+ }
+}
+
+static void
+motion (GtkEventControllerMotion *controller,
+ double x,
+ double y,
+ CurveEditor *self)
+{
+ graphene_point_t m = GRAPHENE_POINT_INIT (x, y);
+ int i, j;
+ gboolean changed = FALSE;
+
+ if (self->edit)
+ {
+ for (i = 0; i < self->segments->len; i++)
+ {
+ Segment *seg = get_segment (self, i);
+ int hovered = -1;
+
+ for (j = 0; j < 3; j++)
+ {
+ const graphene_point_t *q = &seg->p[j];
+
+ if (!point_is_visible (self, i, j))
+ continue;
+
+ if (graphene_point_distance (q, &m, NULL, NULL) < CLICK_RADIUS)
+ {
+ hovered = j;
+ break;
+ }
+ }
+ if (seg->hovered != hovered)
+ {
+ seg->hovered = hovered;
+ changed = TRUE;
+ }
+ }
+ }
+
+ if (changed)
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+leave (GtkEventController *controller,
+ CurveEditor *self)
+{
+ int i;
+ gboolean changed = FALSE;
+
+ for (i = 0; i < self->segments->len; i++)
+ {
+ Segment *seg = get_segment (self, i);
+ if (seg->hovered != -1)
+ {
+ seg->hovered = -1;
+ changed = TRUE;
+ }
+ }
+
+ if (changed)
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+/* }}} */
+/* {{{ Snapshot */
+
+static void
+add_diamond (GskPathBuilder *builder,
+ graphene_point_t *center,
+ float radius)
+{
+ float r = radius * 2 / (1 + M_SQRT2);
+
+ gsk_path_builder_move_to (builder, center->x, center->y - r * M_SQRT2);
+ gsk_path_builder_line_to (builder, center->x + r * M_SQRT2, center->y);
+ gsk_path_builder_line_to (builder, center->x, center->y + r * M_SQRT2);
+ gsk_path_builder_line_to (builder, center->x - r * M_SQRT2, center->y);
+ gsk_path_builder_close (builder);
+}
+
+static void
+add_square (GskPathBuilder *builder,
+ graphene_point_t *center,
+ float radius)
+{
+ float r = radius * 2 / (1 + M_SQRT2);
+
+ gsk_path_builder_move_to (builder, center->x - r, center->y - r);
+ gsk_path_builder_line_to (builder, center->x + r, center->y - r);
+ gsk_path_builder_line_to (builder, center->x + r, center->y + r);
+ gsk_path_builder_line_to (builder, center->x - r, center->y + r);
+ gsk_path_builder_close (builder);
+}
+
+static void
+curve_editor_snapshot (GtkWidget *widget,
+ GtkSnapshot *snapshot)
+{
+ CurveEditor *self = (CurveEditor *)widget;
+ GskPathBuilder *builder;
+ GskPath *path;
+ GskStroke *stroke;
+ int i, j, k;
+ float width;
+ float height;
+
+ if (self->segments->len == 0)
+ return;
+
+ width = gtk_widget_get_width (widget);
+ height = gtk_widget_get_width (widget);
+
+ /* Add the curve itself */
+
+ builder = gsk_path_builder_new ();
+
+ curve_editor_add_path (self, builder);
+
+ path = gsk_path_builder_free_to_path (builder);
+
+ stroke = gsk_stroke_copy (self->stroke);
+ if (self->show_outline)
+ gsk_stroke_set_line_width (stroke, 1.0);
+ gtk_snapshot_push_stroke (snapshot, path, stroke);
+ gsk_stroke_free (stroke);
+
+ gtk_snapshot_append_color (snapshot,
+ &self->color,
+ &GRAPHENE_RECT_INIT (0, 0, width, height ));
+
+ gtk_snapshot_pop (snapshot);
+
+ if (self->show_outline)
+ {
+ GskPath *path2;
+
+ path2 = gsk_path_stroke (path, self->stroke);
+
+ stroke = gsk_stroke_copy (self->stroke);
+ gsk_stroke_set_line_width (stroke, 1.0);
+ gsk_stroke_set_dash (stroke, NULL, 0);
+ gtk_snapshot_push_stroke (snapshot, path2, stroke);
+ gsk_stroke_free (stroke);
+
+ gtk_snapshot_append_color (snapshot,
+ &(GdkRGBA){ 0, 0, 0, 1 },
+ &GRAPHENE_RECT_INIT (0, 0, width, height ));
+
+ gtk_snapshot_pop (snapshot);
+
+ gsk_path_unref (path2);
+ }
+
+ gsk_path_unref (path);
+
+ if (self->edit)
+ {
+ builder = gsk_path_builder_new ();
+
+ if (self->edited_point != -1)
+ {
+ /* Add the skeleton */
+ Segment *seg = get_segment (self, self->edited_point);
+ Segment *seg1 = get_segment (self, self->edited_point - 1);
+ const graphene_point_t *p = get_line_point (self, self->edited_point);
+
+ if (seg1->op == GSK_PATH_CURVE)
+ {
+ graphene_point_t *c = &seg1->p[2];
+ gsk_path_builder_move_to (builder, c->x, c->y);
+ gsk_path_builder_line_to (builder, p->x, p->y);
+ }
+ else if (seg1->op == GSK_PATH_CONIC)
+ {
+ graphene_point_t *c = &seg1->p[1];
+ gsk_path_builder_move_to (builder, c->x, c->y);
+ gsk_path_builder_line_to (builder, p->x, p->y);
+ }
+
+ if (seg->op == GSK_PATH_CURVE)
+ {
+ graphene_point_t *c = &seg->p[1];
+ gsk_path_builder_move_to (builder, c->x, c->y);
+ gsk_path_builder_line_to (builder, p->x, p->y);
+ }
+ else if (seg->op == GSK_PATH_CONIC)
+ {
+ graphene_point_t *c = &seg->p[1];
+ gsk_path_builder_move_to (builder, p->x, p->y);
+ gsk_path_builder_line_to (builder, c->x, c->y);
+ }
+ }
+
+ if (self->edited_segment != -1)
+ {
+ Segment *seg = get_segment (self, self->edited_segment);
+
+ if (seg->op == GSK_PATH_CURVE)
+ {
+ gsk_path_builder_move_to (builder, seg->p[0].x, seg->p[0].y);
+ gsk_path_builder_line_to (builder, seg->p[1].x, seg->p[1].y);
+ gsk_path_builder_line_to (builder, seg->p[2].x, seg->p[2].y);
+ gsk_path_builder_line_to (builder, seg->p[3].x, seg->p[3].y);
+ }
+ else if (seg->op == GSK_PATH_CONIC)
+ {
+ gsk_path_builder_move_to (builder, seg->p[0].x, seg->p[0].y);
+ gsk_path_builder_line_to (builder, seg->p[1].x, seg->p[1].y);
+ gsk_path_builder_line_to (builder, seg->p[3].x, seg->p[3].y);
+ }
+ }
+
+ path = gsk_path_builder_free_to_path (builder);
+
+ if (self->edited_point != -1 || self->edited_segment != -1)
+ {
+ stroke = gsk_stroke_new (1);
+ gtk_snapshot_push_stroke (snapshot, path, stroke);
+ gsk_stroke_free (stroke);
+
+ gtk_snapshot_append_color (snapshot,
+ &(GdkRGBA){ 0, 0, 0, 1 },
+ &GRAPHENE_RECT_INIT (0, 0, width, height ));
+
+ gtk_snapshot_pop (snapshot);
+ }
+
+ gsk_path_unref (path);
+
+ /* Draw the circles, in several passes, one for each color */
+
+ const char *colors[] = {
+ "red", /* hovered */
+ "white" /* smooth curve points */
+ };
+ GdkRGBA color;
+
+ for (k = 0; k < 2; k++)
+ {
+ builder = gsk_path_builder_new ();
+
+ for (i = 0; i < self->segments->len; i++)
+ {
+ Segment *seg = get_segment (self, i);
+
+ for (j = 0; j < 3; j++)
+ {
+ graphene_point_t *p = &seg->p[j];
+
+ if (!point_is_visible (self, i, j))
+ continue;
+
+ if ((k == 0 && j != seg->hovered) ||
+ (k == 1 && j == seg->hovered))
+ continue;
+
+ if (j != 0)
+ {
+ gsk_path_builder_add_circle (builder, p, DRAW_RADIUS);
+ }
+ else
+ {
+ switch (seg->type)
+ {
+ case CUSP:
+ add_diamond (builder, p, DRAW_RADIUS);
+ break;
+
+ case SMOOTH:
+ add_square (builder, p, DRAW_RADIUS);
+ break;
+ case SYMMETRIC:
+ case AUTO:
+ gsk_path_builder_add_circle (builder, p, DRAW_RADIUS);
+ break;
+ default:
+ g_assert_not_reached ();
+ }
+ }
+ }
+ }
+
+ path = gsk_path_builder_free_to_path (builder);
+
+ gtk_snapshot_push_fill (snapshot, path, GSK_FILL_RULE_WINDING);
+ gdk_rgba_parse (&color, colors[k]);
+ gtk_snapshot_append_color (snapshot,
+ &color,
+ &GRAPHENE_RECT_INIT (0, 0, width, height));
+ gtk_snapshot_pop (snapshot);
+
+ stroke = gsk_stroke_new (1.0);
+ gtk_snapshot_push_stroke (snapshot, path, stroke);
+ gsk_stroke_free (stroke);
+
+ gtk_snapshot_append_color (snapshot,
+ &(GdkRGBA){ 0, 0, 0, 1 },
+ &GRAPHENE_RECT_INIT (0, 0, width, height));
+ gtk_snapshot_pop (snapshot);
+
+ gsk_path_unref (path);
+ }
+ }
+}
+
+/* }}} */
+/* {{{ GtkWidget boilerplate */
+
+static void
+curve_editor_measure (GtkWidget *widget,
+ GtkOrientation orientation,
+ int for_size,
+ int *minimum_size,
+ int *natural_size,
+ int *minimum_baseline,
+ int *natural_baseline)
+{
+ *minimum_size = 100;
+ *natural_size = 200;
+}
+
+static void
+curve_editor_size_allocate (GtkWidget *widget,
+ int width,
+ int height,
+ int baseline)
+{
+ CurveEditor *self = CURVE_EDITOR (widget);
+
+ gtk_popover_present (GTK_POPOVER (self->menu));
+}
+
+/* }}} */
+/* {{{ GObject boilerplate */
+
+static void
+curve_editor_dispose (GObject *object)
+{
+ CurveEditor *self = CURVE_EDITOR (object);
+
+ g_clear_pointer (&self->segments, g_array_unref);
+ g_clear_pointer (&self->menu, gtk_widget_unparent);
+ g_clear_object (&self->actions);
+
+ G_OBJECT_CLASS (curve_editor_parent_class)->dispose (object);
+}
+
+static void
+curve_editor_class_init (CurveEditorClass *class)
+{
+ GObjectClass *object_class = G_OBJECT_CLASS (class);
+ GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+
+ object_class->dispose = curve_editor_dispose;
+
+ widget_class->snapshot = curve_editor_snapshot;
+ widget_class->measure = curve_editor_measure;
+ widget_class->size_allocate = curve_editor_size_allocate;
+}
+
+/* }}} */
+/* {{{ Setup */
+
+static void
+curve_editor_init (CurveEditor *self)
+{
+ GtkEventController *controller;
+ GMenu *menu;
+ GMenu *section;
+ GMenuItem *item;
+ GSimpleAction *action;
+
+ self->segments = g_array_new (FALSE, FALSE, sizeof (Segment));
+ self->dragged = -1;
+ self->molded = -1;
+ self->edited_point = -1;
+ self->edited_segment = -1;
+ self->edit = FALSE;
+ self->stroke = gsk_stroke_new (1.0);
+ self->color = (GdkRGBA){ 0, 0, 0, 1 };
+
+ controller = GTK_EVENT_CONTROLLER (gtk_gesture_drag_new ());
+ gtk_gesture_single_set_button (GTK_GESTURE_SINGLE (controller), GDK_BUTTON_PRIMARY);
+ g_signal_connect (controller, "drag-begin", G_CALLBACK (drag_begin), self);
+ g_signal_connect (controller, "drag-update", G_CALLBACK (drag_update), self);
+ g_signal_connect (controller, "drag-end", G_CALLBACK (drag_end), self);
+ gtk_widget_add_controller (GTK_WIDGET (self), controller);
+
+ controller = GTK_EVENT_CONTROLLER (gtk_gesture_click_new ());
+ gtk_gesture_single_set_button (GTK_GESTURE_SINGLE (controller), 0);
+ g_signal_connect (controller, "pressed", G_CALLBACK (pressed), self);
+ g_signal_connect (controller, "released", G_CALLBACK (released), self);
+ gtk_widget_add_controller (GTK_WIDGET (self), controller);
+
+ controller = gtk_event_controller_motion_new ();
+ g_signal_connect (controller, "motion", G_CALLBACK (motion), self);
+ g_signal_connect (controller, "leave", G_CALLBACK (leave), self);
+ gtk_widget_add_controller (GTK_WIDGET (self), controller);
+
+ self->actions = G_ACTION_MAP (g_simple_action_group_new ());
+
+ action = g_simple_action_new_stateful ("set-point-type", G_VARIANT_TYPE_STRING, g_variant_new_string
("smooth"));
+ g_signal_connect (action, "change-state", G_CALLBACK (set_point_type), self);
+ g_action_map_add_action (G_ACTION_MAP (self->actions), G_ACTION (action));
+ gtk_widget_insert_action_group (GTK_WIDGET (self), "point", G_ACTION_GROUP (self->actions));
+
+ action = g_simple_action_new_stateful ("set-segment-type", G_VARIANT_TYPE_STRING, g_variant_new_string
("curve"));
+ g_signal_connect (action, "change-state", G_CALLBACK (set_operation), self);
+ g_action_map_add_action (G_ACTION_MAP (self->actions), G_ACTION (action));
+
+ action = g_simple_action_new_stateful ("edit-point", NULL, g_variant_new_boolean (FALSE));
+ g_signal_connect (action, "change-state", G_CALLBACK (toggle_edit_point), self);
+ g_action_map_add_action (G_ACTION_MAP (self->actions), G_ACTION (action));
+
+ action = g_simple_action_new_stateful ("edit-segment", NULL, g_variant_new_boolean (FALSE));
+ g_signal_connect (action, "change-state", G_CALLBACK (toggle_edit_segment), self);
+ g_action_map_add_action (G_ACTION_MAP (self->actions), G_ACTION (action));
+
+ action = g_simple_action_new ("add-point", NULL);
+ g_signal_connect (action, "activate", G_CALLBACK (insert_new_point), self);
+ g_action_map_add_action (G_ACTION_MAP (self->actions), G_ACTION (action));
+
+ action = g_simple_action_new ("remove-point", NULL);
+ g_signal_connect (action, "activate", G_CALLBACK (remove_current_point), self);
+ g_action_map_add_action (G_ACTION_MAP (self->actions), G_ACTION (action));
+
+ action = g_simple_action_new ("reset-weight", NULL);
+ g_signal_connect (action, "activate", G_CALLBACK (reset_weight), self);
+ g_action_map_add_action (G_ACTION_MAP (self->actions), G_ACTION (action));
+
+ gtk_widget_insert_action_group (GTK_WIDGET (self), "path", G_ACTION_GROUP (self->actions));
+
+ menu = g_menu_new ();
+
+ section = g_menu_new ();
+
+ item = g_menu_item_new ("Cusp", "path.set-point-type::cusp");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ item = g_menu_item_new ("Smooth", "path.set-point-type::smooth");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ item = g_menu_item_new ("Symmetric", "path.set-point-type::symmetric");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ item = g_menu_item_new ("Automatic", "path.set-point-type::auto");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ g_menu_append_section (menu, NULL, G_MENU_MODEL (section));
+ g_object_unref (section);
+
+ section = g_menu_new ();
+
+ item = g_menu_item_new ("Line", "path.set-segment-type::line");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ item = g_menu_item_new ("Curve", "path.set-segment-type::curve");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ item = g_menu_item_new ("Conic", "path.set-segment-type::conic");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ g_menu_append_section (menu, NULL, G_MENU_MODEL (section));
+ g_object_unref (section);
+
+ section = g_menu_new ();
+
+ item = g_menu_item_new ("Edit", "path.edit-point");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ item = g_menu_item_new ("Edit", "path.edit-segment");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ g_menu_append_section (menu, NULL, G_MENU_MODEL (section));
+ g_object_unref (section);
+
+ section = g_menu_new ();
+
+ item = g_menu_item_new ("Add", "path.add-point");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ item = g_menu_item_new ("Remove", "path.remove-point");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ item = g_menu_item_new ("Reset", "path.reset-weight");
+ g_menu_item_set_attribute_value (item, "hidden-when", g_variant_new_string ("action-disabled"));
+ g_menu_append_item (section, item);
+ g_object_unref (item);
+
+ g_menu_append_section (menu, NULL, G_MENU_MODEL (section));
+ g_object_unref (section);
+
+ self->menu = gtk_popover_menu_new_from_model (G_MENU_MODEL (menu));
+ g_object_unref (menu);
+
+ gtk_widget_set_parent (self->menu, GTK_WIDGET (self));
+}
+
+/* }}} */
+/* {{{ API */
+
+GtkWidget *
+curve_editor_new (void)
+{
+ return g_object_new (curve_editor_get_type (), NULL);
+}
+
+void
+curve_editor_set_edit (CurveEditor *self,
+ gboolean edit)
+{
+ self->edit = edit;
+ self->edited_point = -1;
+ self->edited_segment = -1;
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static gboolean
+copy_segments (GskPathOperation op,
+ const graphene_point_t *pts,
+ gsize n_pts,
+ float weight,
+ gpointer data)
+{
+ CurveEditor *self = data;
+ Segment seg;
+
+ seg.op = op;
+ seg.hovered = -1;
+ seg.dragged = -1;
+
+ switch (op)
+ {
+ case GSK_PATH_MOVE:
+ break;
+
+ case GSK_PATH_CLOSE:
+ seg.p[0] = pts[0];
+ seg.p[3] = pts[1];
+ g_array_append_val (self->segments, seg);
+ break;
+
+ case GSK_PATH_LINE:
+ seg.p[0] = pts[0];
+ seg.p[3] = pts[1];
+ g_array_append_val (self->segments, seg);
+ break;
+
+ case GSK_PATH_CURVE:
+ seg.p[0] = pts[0];
+ seg.p[1] = pts[1];
+ seg.p[2] = pts[2];
+ seg.p[3] = pts[3];
+ g_array_append_val (self->segments, seg);
+ break;
+
+ case GSK_PATH_CONIC:
+ {
+ seg.p[0] = pts[0];
+ seg.p[1] = pts[1];
+ seg.p[3] = pts[2];
+ seg.weight = weight;
+
+ get_conic_shoulder_point (pts, weight, &seg.p[2]);
+
+ g_array_append_val (self->segments, seg);
+ }
+ break;
+
+ default:
+ g_assert_not_reached ();
+ }
+
+ return TRUE;
+}
+void
+curve_editor_set_path (CurveEditor *self,
+ GskPath *path)
+{
+ int i;
+ Segment *first, *last;
+
+ g_array_set_size (self->segments, 0);
+
+ gsk_path_foreach (path, GSK_PATH_FOREACH_ALLOW_CURVE | GSK_PATH_FOREACH_ALLOW_CONIC, copy_segments, self);
+
+ first = get_segment (self, 0);
+ last = get_segment (self, self->segments->len - 1);
+ if (last->op == GSK_PATH_CLOSE)
+ {
+ if (graphene_point_near (&last->p[0], &last->p[3], 0.001))
+ g_array_remove_index (self->segments, self->segments->len - 1);
+ else
+ last->op = GSK_PATH_LINE;
+ }
+ else
+ {
+ Segment seg;
+
+ seg.op = GSK_PATH_MOVE;
+ seg.p[0] = last->p[3];
+ seg.p[3] = first->p[0];
+ g_array_append_val (self->segments, seg);
+ }
+
+ for (i = 0; i < self->segments->len; i++)
+ check_smoothness (self, i);
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+GskPath *
+curve_editor_get_path (CurveEditor *self)
+{
+ GskPathBuilder *builder;
+
+ builder = gsk_path_builder_new ();
+
+ curve_editor_add_path (self, builder);
+
+ return gsk_path_builder_free_to_path (builder);
+}
+
+void
+curve_editor_set_stroke (CurveEditor *self,
+ GskStroke *stroke)
+{
+ gsk_stroke_free (self->stroke);
+ self->stroke = gsk_stroke_copy (stroke);
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+const GskStroke *
+curve_editor_get_stroke (CurveEditor *self)
+{
+ return self->stroke;
+}
+
+void
+curve_editor_set_color (CurveEditor *self,
+ GdkRGBA *color)
+{
+ self->color = *color;
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+const GdkRGBA *
+curve_editor_get_color (CurveEditor *self)
+{
+ return &self->color;
+}
+
+void
+curve_editor_set_show_outline (CurveEditor *self,
+ gboolean show_outline)
+{
+ self->show_outline = show_outline;
+
+ gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+gboolean
+curve_editor_get_show_outline (CurveEditor *self)
+{
+ return self->show_outline;
+}
+
+/* }}} */
+
+/* vim:set foldmethod=marker expandtab: */
diff --git a/demos/gtk-demo/curve-editor.h b/demos/gtk-demo/curve-editor.h
new file mode 100644
index 0000000000..e62738ccbc
--- /dev/null
+++ b/demos/gtk-demo/curve-editor.h
@@ -0,0 +1,36 @@
+#pragma once
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define CURVE_TYPE_EDITOR (curve_editor_get_type ())
+G_DECLARE_FINAL_TYPE (CurveEditor, curve_editor, CURVE, EDITOR, GtkWidget)
+
+GtkWidget * curve_editor_new (void);
+
+void curve_editor_set_edit (CurveEditor *self,
+ gboolean edit);
+
+void curve_editor_set_path (CurveEditor *self,
+ GskPath *path);
+
+GskPath * curve_editor_get_path (CurveEditor *self);
+
+void curve_editor_set_stroke (CurveEditor *self,
+ GskStroke *stroke);
+
+const GskStroke * curve_editor_get_stroke (CurveEditor *self);
+
+
+void curve_editor_set_color (CurveEditor *self,
+ GdkRGBA *color);
+
+const GdkRGBA * curve_editor_get_color (CurveEditor *self);
+
+gboolean curve_editor_get_show_outline (CurveEditor *self);
+
+void curve_editor_set_show_outline (CurveEditor *self,
+ gboolean show_outline);
+
+G_END_DECLS
diff --git a/demos/gtk-demo/curve.c b/demos/gtk-demo/curve.c
new file mode 100644
index 0000000000..5974838b88
--- /dev/null
+++ b/demos/gtk-demo/curve.c
@@ -0,0 +1,272 @@
+/* Path/Curve Editor
+ *
+ * This demo shows an elaborate curve editor that you would expect to find
+ * in a vector graphics editor. It is built on top of GTK's path APIs.
+ */
+
+#include <gtk/gtk.h>
+#include "curve-editor.h"
+
+
+static GskPath *
+make_circle_path (void)
+{
+ float w = 310;
+ float h = 310;
+ float cx = w / 2;
+ float cy = h / 2;
+ float pad = 20;
+ float r = (w - 2 * pad) / 2;
+ float k = 0.55228;
+ float kr = k * r;
+ GskPathBuilder *builder;
+
+ builder = gsk_path_builder_new ();
+
+ gsk_path_builder_move_to (builder, cx, pad);
+ gsk_path_builder_curve_to (builder, cx + kr, pad,
+ w - pad, cy - kr,
+ w - pad, cy);
+ gsk_path_builder_curve_to (builder, w - pad, cy + kr,
+ cx + kr, h - pad,
+ cx, h - pad);
+ gsk_path_builder_curve_to (builder, cx - kr, h - pad,
+ pad, cy + kr,
+ pad, cy);
+ gsk_path_builder_curve_to (builder, pad, cy - kr,
+ cx - kr, pad,
+ cx, pad);
+ gsk_path_builder_close (builder);
+
+ return gsk_path_builder_free_to_path (builder);
+}
+
+static void
+edit_changed (GtkToggleButton *button,
+ GParamSpec *pspec,
+ CurveEditor *editor)
+{
+ curve_editor_set_edit (editor, gtk_toggle_button_get_active (button));
+}
+
+static void
+reset (GtkButton *button,
+ CurveEditor *editor)
+{
+ GskPath *path;
+
+ path = make_circle_path ();
+ curve_editor_set_path (editor, path);
+ gsk_path_unref (path);
+}
+
+static void
+line_width_changed (GtkSpinButton *spin,
+ CurveEditor *editor)
+{
+ GskStroke *stroke;
+
+ stroke = gsk_stroke_copy (curve_editor_get_stroke (editor));
+ gsk_stroke_set_line_width (stroke, gtk_spin_button_get_value (spin));
+ curve_editor_set_stroke (editor, stroke);
+ gsk_stroke_free (stroke);
+}
+
+static void
+cap_changed (GtkDropDown *combo,
+ GParamSpec *pspec,
+ CurveEditor *editor)
+{
+ GskStroke *stroke;
+
+ stroke = gsk_stroke_copy (curve_editor_get_stroke (editor));
+ gsk_stroke_set_line_cap (stroke, (GskLineCap)gtk_drop_down_get_selected (combo));
+ curve_editor_set_stroke (editor, stroke);
+ gsk_stroke_free (stroke);
+}
+
+static void
+join_changed (GtkDropDown *combo,
+ GParamSpec *pspec,
+ CurveEditor *editor)
+{
+ GskStroke *stroke;
+
+ stroke = gsk_stroke_copy (curve_editor_get_stroke (editor));
+ gsk_stroke_set_line_join (stroke, (GskLineJoin)gtk_drop_down_get_selected (combo));
+ curve_editor_set_stroke (editor, stroke);
+ gsk_stroke_free (stroke);
+}
+
+static void
+color_changed (GtkColorChooser *chooser,
+ GParamSpec *pspec,
+ CurveEditor *editor)
+{
+ GdkRGBA color;
+
+ gtk_color_chooser_get_rgba (chooser, &color);
+ curve_editor_set_color (editor, &color);
+}
+
+static void
+stroke_toggled (GtkCheckButton *button,
+ CurveEditor *editor)
+{
+ curve_editor_set_show_outline (editor, gtk_check_button_get_active (button));
+ gtk_widget_queue_draw (GTK_WIDGET (editor));
+}
+
+static void
+limit_changed (GtkSpinButton *spin,
+ CurveEditor *editor)
+{
+ GskStroke *stroke;
+
+ stroke = gsk_stroke_copy (curve_editor_get_stroke (editor));
+ gsk_stroke_set_miter_limit (stroke, gtk_spin_button_get_value (spin));
+ curve_editor_set_stroke (editor, stroke);
+ gsk_stroke_free (stroke);
+}
+
+static void
+dashes_changed (GtkEntry *entry,
+ GParamSpec *spec,
+ CurveEditor *editor)
+{
+ const char *text;
+ char **split;
+ GArray *dash;
+ GskStroke *stroke;
+
+ text = gtk_editable_get_text (GTK_EDITABLE (entry));
+ split = g_strsplit (text, " ", 0);
+
+ dash = g_array_new (FALSE, FALSE, sizeof (float));
+ for (int i = 0; split[i] != NULL; i++)
+ {
+ double d;
+ char *endp = 0;
+
+ d = g_strtod (split[i], &endp);
+ if (*endp == '\0')
+ g_array_append_vals (dash, (float[1]) { d }, 1);
+ }
+
+ g_strfreev (split);
+
+ stroke = gsk_stroke_copy (curve_editor_get_stroke (editor));
+ gsk_stroke_set_dash (stroke, (const float *)dash->data, dash->len);
+ curve_editor_set_stroke (editor, stroke);
+ gsk_stroke_free (stroke);
+
+ g_array_free (dash, TRUE);
+}
+
+GtkWidget *
+do_curve (GtkWidget *do_widget)
+{
+ static GtkWidget *window = NULL;
+ GtkWidget *demo;
+ GtkWidget *edit_toggle;
+ GtkWidget *reset_button;
+ GtkWidget *titlebar;
+ GtkWidget *stroke_toggle;
+ GtkWidget *line_width_spin;
+ GtkWidget *stroke_button;
+ GtkWidget *popover;
+ GtkWidget *grid;
+ GtkWidget *cap_combo;
+ GtkWidget *join_combo;
+ GtkWidget *color_button;
+ GtkWidget *limit_spin;
+ GtkWidget *dash_entry;
+
+ if (!window)
+ {
+ window = gtk_window_new ();
+ gtk_window_set_title (GTK_WINDOW (window), "Curve Editor");
+ g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
+ gtk_window_set_default_size (GTK_WINDOW (window), 310, 350);
+
+ edit_toggle = gtk_toggle_button_new ();
+ gtk_button_set_icon_name (GTK_BUTTON (edit_toggle), "document-edit-symbolic");
+
+ reset_button = gtk_button_new_from_icon_name ("edit-undo-symbolic");
+
+ stroke_button = gtk_menu_button_new ();
+ gtk_menu_button_set_icon_name (GTK_MENU_BUTTON (stroke_button), "open-menu-symbolic");
+ popover = gtk_popover_new ();
+ gtk_menu_button_set_popover (GTK_MENU_BUTTON (stroke_button), popover);
+
+ grid = gtk_grid_new ();
+ gtk_grid_set_row_spacing (GTK_GRID (grid), 6);
+ gtk_grid_set_column_spacing (GTK_GRID (grid), 6);
+ gtk_popover_set_child (GTK_POPOVER (popover), grid);
+
+ gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Color:"), 0, 0, 1, 1);
+ color_button = gtk_color_button_new_with_rgba (&(GdkRGBA){ 0., 0., 0., 1.});
+ gtk_grid_attach (GTK_GRID (grid), color_button, 1, 0, 1, 1);
+
+ gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Line width:"), 0, 1, 1, 1);
+ line_width_spin = gtk_spin_button_new_with_range (1, 20, 1);
+ gtk_spin_button_set_value (GTK_SPIN_BUTTON (line_width_spin), 1);
+ gtk_grid_attach (GTK_GRID (grid), line_width_spin, 1, 1, 1, 1);
+
+ gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Line cap:"), 0, 2, 1, 1);
+ cap_combo = gtk_drop_down_new_from_strings ((const char *[]){"Butt", "Round", "Square", NULL});
+ gtk_grid_attach (GTK_GRID (grid), cap_combo, 1, 2, 1, 1);
+
+ gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Line join:"), 0, 3, 1, 1);
+ join_combo = gtk_drop_down_new_from_strings ((const char *[]){"Miter", "Miter-clip", "Round", "Bevel",
"Arcs", NULL});
+ gtk_grid_attach (GTK_GRID (grid), join_combo, 1, 3, 1, 1);
+
+ gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Miter limit:"), 0, 4, 1, 1);
+ limit_spin = gtk_spin_button_new_with_range (0, 10, 1);
+ gtk_spin_button_set_digits (GTK_SPIN_BUTTON (limit_spin), 1);
+ gtk_spin_button_set_value (GTK_SPIN_BUTTON (limit_spin), 4);
+ gtk_grid_attach (GTK_GRID (grid), limit_spin, 1, 4, 1, 1);
+
+ gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Dashes:"), 0, 5, 1, 1);
+ dash_entry = gtk_entry_new ();
+ gtk_grid_attach (GTK_GRID (grid), dash_entry, 1, 5, 1, 1);
+
+ stroke_toggle = gtk_check_button_new_with_label ("Show outline");
+ gtk_grid_attach (GTK_GRID (grid), stroke_toggle, 1, 6, 1, 1);
+
+ titlebar = gtk_header_bar_new ();
+ gtk_header_bar_pack_start (GTK_HEADER_BAR (titlebar), edit_toggle);
+ gtk_header_bar_pack_start (GTK_HEADER_BAR (titlebar), reset_button);
+ gtk_header_bar_pack_start (GTK_HEADER_BAR (titlebar), stroke_button);
+
+ gtk_window_set_titlebar (GTK_WINDOW (window), titlebar);
+
+ demo = curve_editor_new ();
+
+ g_signal_connect (stroke_toggle, "toggled", G_CALLBACK (stroke_toggled), demo);
+ g_signal_connect (edit_toggle, "notify::active", G_CALLBACK (edit_changed), demo);
+ g_signal_connect (reset_button, "clicked", G_CALLBACK (reset), demo);
+ g_signal_connect (cap_combo, "notify::selected", G_CALLBACK (cap_changed), demo);
+ g_signal_connect (join_combo, "notify::selected", G_CALLBACK (join_changed), demo);
+ g_signal_connect (color_button, "notify::rgba", G_CALLBACK (color_changed), demo);
+ g_signal_connect (line_width_spin, "value-changed", G_CALLBACK (line_width_changed), demo);
+ g_signal_connect (limit_spin, "value-changed", G_CALLBACK (limit_changed), demo);
+ g_signal_connect (dash_entry, "notify::text", G_CALLBACK (dashes_changed), demo);
+
+ reset (NULL, CURVE_EDITOR (demo));
+
+ gtk_spin_button_set_value (GTK_SPIN_BUTTON (line_width_spin), 6);
+ gtk_color_chooser_set_rgba (GTK_COLOR_CHOOSER (color_button), &(GdkRGBA) { 1, 0, 0, 1 });
+ gtk_drop_down_set_selected (GTK_DROP_DOWN (cap_combo), GSK_LINE_CAP_ROUND);
+ gtk_editable_set_text (GTK_EDITABLE (dash_entry), "0 8");
+
+ gtk_window_set_child (GTK_WINDOW (window), demo);
+ }
+
+ if (!gtk_widget_get_visible (window))
+ gtk_widget_show (window);
+ else
+ gtk_window_destroy (GTK_WINDOW (window));
+
+ return window;
+}
diff --git a/demos/gtk-demo/demo.gresource.xml b/demos/gtk-demo/demo.gresource.xml
index 5492aed444..be87cbcef3 100644
--- a/demos/gtk-demo/demo.gresource.xml
+++ b/demos/gtk-demo/demo.gresource.xml
@@ -249,6 +249,10 @@
<gresource prefix="/video-player">
<file>bbb.png</file>
</gresource>
+ <gresource prefix="/curve">
+ <file>curve-editor.c</file>
+ <file>curve-editor.h</file>
+ </gresource>
<gresource prefix="/sources">
<file>application_demo.c</file>
<file>assistant.c</file>
@@ -266,6 +270,7 @@
<file>css_pixbufs.c</file>
<file>css_shadows.c</file>
<file>cursors.c</file>
+ <file>curve.c</file>
<file>dialog.c</file>
<file>drawingarea.c</file>
<file>dropdown.c</file>
diff --git a/demos/gtk-demo/meson.build b/demos/gtk-demo/meson.build
index 8b7eb3ef64..98d4fd0f39 100644
--- a/demos/gtk-demo/meson.build
+++ b/demos/gtk-demo/meson.build
@@ -17,6 +17,7 @@ demos = files([
'css_pixbufs.c',
'css_shadows.c',
'cursors.c',
+ 'curve.c',
'dialog.c',
'drawingarea.c',
'dnd.c',
@@ -131,6 +132,7 @@ extra_demo_sources = files([
'script-names.c',
'unicode-names.c',
'suggestionentry.c',
+ 'curve-editor.c',
])
if harfbuzz_dep.found() and pangoft_dep.found()
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