[gimp] app: change segment drawing to using pixel centers and CAP_SQUARE line ends

[Michael Natterer <mitch src gnome org>]

commit 612aee9f334e19ce5fae9d0b50d479702b53d3ef
Author: Michael Natterer <mitch gimp org>
Date:   Thu Sep 23 14:26:52 2010 +0200

    app: change segment drawing to using pixel centers and CAP_SQUARE line ends
    
    This looks exactly the same for the selection, but is needed like that
    for segment drawing in tools.

 app/display/gimpdisplayshell-selection.c |    1 +
 app/display/gimpdisplayshell-style.c     |    8 ++++++--
 app/widgets/gimpcairo.c                  |    8 ++++----
 3 files changed, 11 insertions(+), 6 deletions(-)
---
diff --git a/app/display/gimpdisplayshell-selection.c b/app/display/gimpdisplayshell-selection.c
index 8e54ed3..cbbfe49 100644
--- a/app/display/gimpdisplayshell-selection.c
+++ b/app/display/gimpdisplayshell-selection.c
@@ -385,6 +385,7 @@ selection_render_mask (Selection *selection)
 
   cairo_push_group_with_content (cr, CAIRO_CONTENT_ALPHA);
 
+  cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
   cairo_set_line_width (cr, 1.0);
 
   gimp_cairo_add_segments (cr,
diff --git a/app/display/gimpdisplayshell-style.c b/app/display/gimpdisplayshell-style.c
index bcb19d1..e0f2146 100644
--- a/app/display/gimpdisplayshell-style.c
+++ b/app/display/gimpdisplayshell-style.c
@@ -224,6 +224,7 @@ gimp_display_shell_set_layer_style (GimpDisplayShell *shell,
   g_return_if_fail (GIMP_IS_DRAWABLE (drawable));
 
   cairo_set_line_width (cr, 1.0);
+  cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
 
   if (GIMP_IS_LAYER_MASK (drawable))
     {
@@ -258,6 +259,7 @@ gimp_display_shell_set_selection_out_style (GimpDisplayShell *shell,
   g_return_if_fail (cr != NULL);
 
   cairo_set_line_width (cr, 1.0);
+  cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
 
   pattern = gimp_cairo_stipple_pattern_create (&selection_out_fg,
                                                &selection_out_bg,
@@ -326,9 +328,10 @@ gimp_display_shell_set_tool_bg_style (GimpDisplayShell *shell,
   g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
   g_return_if_fail (cr != NULL);
 
+  cairo_set_line_width (cr, 3.0);
   cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
   cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
-  cairo_set_line_width (cr, 3.0);
+
   gimp_cairo_set_source_rgba (cr, &tool_bg);
 }
 
@@ -339,8 +342,9 @@ gimp_display_shell_set_tool_fg_style (GimpDisplayShell *shell,
   g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
   g_return_if_fail (cr != NULL);
 
+  cairo_set_line_width (cr, 1.0);
   cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
   cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
-  cairo_set_line_width (cr, 1.0);
+
   gimp_cairo_set_source_rgba (cr, &tool_fg);
 }
diff --git a/app/widgets/gimpcairo.c b/app/widgets/gimpcairo.c
index c115f74..86738ba 100644
--- a/app/widgets/gimpcairo.c
+++ b/app/widgets/gimpcairo.c
@@ -101,13 +101,13 @@ gimp_cairo_add_segments (cairo_t    *cr,
     {
       if (segs[i].x1 == segs[i].x2)
         {
-          cairo_move_to (cr, segs[i].x1 + 0.5, segs[i].y1);
-          cairo_line_to (cr, segs[i].x2 + 0.5, segs[i].y2);
+          cairo_move_to (cr, segs[i].x1 + 0.5, segs[i].y1 + 0.5);
+          cairo_line_to (cr, segs[i].x2 + 0.5, segs[i].y2 - 1.0);
         }
       else
         {
-          cairo_move_to (cr, segs[i].x1, segs[i].y1 + 0.5);
-          cairo_line_to (cr, segs[i].x2, segs[i].y2 + 0.5);
+          cairo_move_to (cr, segs[i].x1 + 0.5, segs[i].y1 + 0.5);
+          cairo_line_to (cr, segs[i].x2 - 1.0, segs[i].y2 + 0.5);
         }
     }
 }