Consistent naming pattern for shader variables.

data/shaders/default.frag

@@ -1,12 +1,13 @@
 #version 120
 
-varying vec4 color_mod;
-varying vec4 color_draw;
-varying vec2 pos;
-varying float submerge_amount;
+varying vec4 frag_color_mod;
+varying vec4 frag_draw_color;
+varying vec2 frag_texture_pos;
+varying float frag_submerge;
 uniform sampler2D tex;
 
 void main()
 {
-	gl_FragColor = texture2D(tex, pos) + color_draw + color_mod;
+	gl_FragColor = texture2D(tex, frag_texture_pos)
+					+ frag_draw_color + frag_color_mod;
 }

data/shaders/default.vert

@@ -1,24 +1,24 @@
 #version 120
 
 // Required by SDL_gpu
-attribute vec4 draw_color;
-attribute vec3 vertex;
-attribute vec2 texture_pos;
-attribute vec4 color;
-attribute float submerge;
+attribute vec4 vert_draw_color;
+attribute vec3 vert_vertex;
+attribute vec2 vert_texture_pos;
+attribute vec4 vert_color_mod;
+attribute float vert_submerge;
 
 uniform mat4 model_view_proj;
 
-varying vec4 color_mod;
-varying vec2 pos;
-varying float submerge_amount;
-varying vec4 color_draw;
+varying vec4 frag_color_mod;
+varying vec2 frag_texture_pos;
+varying float frag_submerge;
+varying vec4 frag_draw_color;
 
 void main()
 {
-	pos = vec2(texture_pos);
-	color_mod = color;
-	color_draw = draw_color;
-	submerge_amount = submerge;
-	gl_Position = model_view_proj * vec4(vertex, 1.0);
+	frag_texture_pos = vert_texture_pos;
+	frag_color_mod = vert_color_mod;
+	frag_draw_color = vert_draw_color;
+	frag_submerge = vert_submerge;
+	gl_Position = model_view_proj * vec4(vert_vertex, 1.0);
 }

src/sdl/shader.cpp

@@ -42,7 +42,8 @@ shader_program::shader_program(const std::string &vsrc, const std::string &fsrc)
 		//TODO: report error
 	}
 
-	attr_color_mod_ = GPU_GetAttributeLocation(program_object_, "color");
+	attr_color_mod_ = GPU_GetAttributeLocation(program_object_,
+											   "vert_color_mod");
 	set_color_mod(0, 0, 0, 0);
 	set_submerge(0);
 }
@@ -92,8 +93,9 @@ const shader_program &shader_program::operator =(const shader_program &prog)
 
 void shader_program::activate()
 {
-	block_ = GPU_LoadShaderBlock(program_object_, "vertex", "texture_pos",
-								 "draw_color", "model_view_proj");
+	block_ = GPU_LoadShaderBlock(program_object_, "vert_vertex",
+								 "vert_texture_pos", "vert_draw_color",
+								 "model_view_proj");
 	GPU_ActivateShaderProgram(program_object_, &block_);
 }