[gtk+/wip/ebassi/gsk-renderer: 52/65] gsk: Don't store the uniform and attribute location twice

[Emmanuele Bassi <ebassi src gnome org>]

commit e4da7fea0777132c6097d6995afb94049d435fc6
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Sun Jul 3 22:54:30 2016 +0100

    gsk: Don't store the uniform and attribute location twice
    
    We should keep the ShaderBuilder around and use it to query the various
    uniform and attribute locations when needed, instead of storing those
    offsets into the Renderer instance, and copying them. This allows a bit
    more flexibility, once we have more than one program built into the
    renderer.

 gsk/gskglrenderer.c |  119 +++++++++++++++++++++++++--------------------------
 1 files changed, 59 insertions(+), 60 deletions(-)
---
diff --git a/gsk/gskglrenderer.c b/gsk/gskglrenderer.c
index fd8ee8d..3f2a213 100644
--- a/gsk/gskglrenderer.c
+++ b/gsk/gskglrenderer.c
@@ -13,6 +13,10 @@
 
 #include <epoxy/gl.h>
 
+#define SHADER_VERSION_GLES             110
+#define SHADER_VERSION_GL_LEGACY        120
+#define SHADER_VERSION_GL3              150
+
 typedef struct {
   guint vao_id;
   guint buffer_id;
@@ -51,6 +55,21 @@ typedef struct {
   RenderData *parent_data;
 } RenderItem;
 
+enum {
+  MVP,
+  MAP,
+  PARENT_MAP,
+  ALPHA,
+  BLEND_MODE,
+  N_UNIFORMS
+};
+
+enum {
+  POSITION,
+  UV,
+  N_ATTRIBUTES
+};
+
 struct _GskGLRenderer
 {
   GskRenderer parent_instance;
@@ -65,14 +84,10 @@ struct _GskGLRenderer
   guint depth_stencil_buffer;
   guint texture_id;
 
-  guint program_id;
-  guint mvp_location;
-  guint map_location;
-  guint parentMap_location;
-  guint uv_location;
-  guint position_location;
-  guint alpha_location;
-  guint blendMode_location;
+  GQuark uniforms[N_UNIFORMS];
+  GQuark attributes[N_ATTRIBUTES];
+
+  GskShaderBuilder *blend_program;
 
   guint vao_id;
 
@@ -283,41 +298,21 @@ gsk_gl_renderer_create_programs (GskGLRenderer *self)
   const char *vertex_preamble;
   const char *fragment_preamble;
   int vertex_id = -1, fragment_id = -1;
-  int program_id = -1;
   GError *error = NULL;
   gboolean res = FALSE;
-  enum {
-    MVP,
-    MAP,
-    PARENT_MAP,
-    ALPHA,
-    BLEND_MODE,
-    N_UNIFORMS
-  };
-  enum {
-    POSITION,
-    UV,
-    N_ATTRIBUTES
-  };
-  GQuark uniforms[N_UNIFORMS];
-  GQuark attributes[N_ATTRIBUTES];
-  
+
   builder = gsk_shader_builder_new ();
 
   gsk_shader_builder_set_resource_base_path (builder, "/org/gtk/libgsk/glsl");
 
-  uniforms[MVP] = gsk_shader_builder_add_uniform (builder, "mvp");
-  uniforms[MAP] = gsk_shader_builder_add_uniform (builder, "map");
-  uniforms[PARENT_MAP] = gsk_shader_builder_add_uniform (builder, "parentMap");
-  uniforms[ALPHA] = gsk_shader_builder_add_uniform (builder, "alpha");
-  uniforms[BLEND_MODE] = gsk_shader_builder_add_uniform (builder, "blendMode");
+  self->uniforms[MVP] = gsk_shader_builder_add_uniform (builder, "mvp");
+  self->uniforms[MAP] = gsk_shader_builder_add_uniform (builder, "map");
+  self->uniforms[PARENT_MAP] = gsk_shader_builder_add_uniform (builder, "parentMap");
+  self->uniforms[ALPHA] = gsk_shader_builder_add_uniform (builder, "alpha");
+  self->uniforms[BLEND_MODE] = gsk_shader_builder_add_uniform (builder, "blendMode");
   
-  attributes[POSITION] = gsk_shader_builder_add_attribute (builder, "position");
-  attributes[UV] = gsk_shader_builder_add_attribute (builder, "uv");
-
-#define SHADER_VERSION_GLES             110
-#define SHADER_VERSION_GL_LEGACY        120
-#define SHADER_VERSION_GL3              150
+  self->attributes[POSITION] = gsk_shader_builder_add_attribute (builder, "position");
+  self->attributes[UV] = gsk_shader_builder_add_attribute (builder, "uv");
 
   if (gdk_gl_context_get_use_es (self->context))
     {
@@ -371,9 +366,7 @@ gsk_gl_renderer_create_programs (GskGLRenderer *self)
       goto out;
     }
 
-  program_id = gsk_shader_builder_create_program (builder,
-                                                  vertex_id, fragment_id,
-                                                  &error);
+  gsk_shader_builder_create_program (builder, vertex_id, fragment_id, &error);
   if (error != NULL)
     {
       g_critical ("Unable to create program: %s", error->message);
@@ -381,35 +374,31 @@ gsk_gl_renderer_create_programs (GskGLRenderer *self)
       goto out;
     }
 
-  self->program_id = program_id;
-  self->mvp_location = gsk_shader_builder_get_uniform_location (builder, uniforms[MVP]);
-  self->map_location = gsk_shader_builder_get_uniform_location (builder, uniforms[MAP]);
-  self->parentMap_location = gsk_shader_builder_get_uniform_location (builder, uniforms[PARENT_MAP]);
-  self->alpha_location = gsk_shader_builder_get_uniform_location (builder, uniforms[ALPHA]);
-  self->blendMode_location = gsk_shader_builder_get_uniform_location (builder, uniforms[BLEND_MODE]);
-  self->position_location = gsk_shader_builder_get_attribute_location (builder, attributes[POSITION]);
-  self->uv_location = gsk_shader_builder_get_attribute_location (builder, attributes[UV]);
+  self->blend_program = g_object_ref (builder);
 
   res = TRUE;
 
 out:
+  g_object_unref (builder);
+
   if (vertex_id > 0)
     glDeleteShader (vertex_id);
   if (fragment_id > 0)
     glDeleteShader (fragment_id);
 
-  g_object_unref (builder);
-
   return res;
 }
 
 static void
 gsk_gl_renderer_destroy_programs (GskGLRenderer *self)
 {
-  if (self->program_id != 0)
+  if (self->blend_program != NULL)
     {
-      glDeleteProgram (self->program_id);
-      self->program_id = 0;
+      int program_id = gsk_shader_builder_get_program (self->blend_program);
+
+      glDeleteProgram (program_id);
+
+      g_clear_object (&self->blend_program);
     }
 }
 
@@ -777,14 +766,24 @@ gsk_gl_renderer_add_render_item (GskGLRenderer *self,
   /* GL objects */
   item.render_data.vao_id = self->vao_id;
   item.render_data.buffer_id = 0;
-  item.render_data.program_id = self->program_id;
-  item.render_data.map_location = self->map_location;
-  item.render_data.parentMap_location = self->parentMap_location;
-  item.render_data.mvp_location = self->mvp_location;
-  item.render_data.uv_location = self->uv_location;
-  item.render_data.position_location = self->position_location;
-  item.render_data.alpha_location = self->alpha_location;
-  item.render_data.blendMode_location = self->blendMode_location;
+
+  item.render_data.program_id = gsk_shader_builder_get_program (self->blend_program);
+
+  item.render_data.map_location =
+    gsk_shader_builder_get_uniform_location (self->blend_program, self->uniforms[MAP]);
+  item.render_data.parentMap_location =
+    gsk_shader_builder_get_uniform_location (self->blend_program, self->uniforms[PARENT_MAP]);
+  item.render_data.mvp_location =
+    gsk_shader_builder_get_uniform_location (self->blend_program, self->uniforms[MVP]);
+  item.render_data.alpha_location =
+    gsk_shader_builder_get_uniform_location (self->blend_program, self->uniforms[ALPHA]);
+  item.render_data.blendMode_location =
+    gsk_shader_builder_get_uniform_location (self->blend_program, self->uniforms[BLEND_MODE]);
+
+  item.render_data.position_location =
+    gsk_shader_builder_get_attribute_location (self->blend_program, self->attributes[POSITION]);
+  item.render_data.uv_location =
+    gsk_shader_builder_get_attribute_location (self->blend_program, self->attributes[UV]);
 
   if (parent != NULL)
     item.parent_data = &(parent->render_data);