add GLVertexAttrib struct to distinguish from gl_buffer

src/shader.cpp

@@ -437,33 +437,39 @@ parseUniformBlocks(memory_arena* arena, shader_program* s, GLContext* gl_ctx)
 bool
 parseAttributes(memory_arena* arena, shader_program* s, GLContext* gl_ctx)
 {
-	// TODO: parse buffers (vert, normal, uv), glGetActiveAttrib()
-	///
 	printf("\n---------------------------------\n");
 	printf("%s(), FIXME: dumping attrib info for programe: %s\n",
 			__FUNCTION__, s->name);
 
 
-	GLint active_attribs;
-	glGetProgramiv(s->prog_id, GL_ACTIVE_ATTRIBUTES, &active_attribs);
-	printf("active attributes: %d\n", active_attribs);
+	GLint num_attribs;
+	glGetProgramiv(s->prog_id, GL_ACTIVE_ATTRIBUTES, &num_attribs);
+	printf("active attributes: %d\n", num_attribs);
 
-	GLchar attrib_name[256];
+	s->num_vertex_attribs = num_attribs;
+	s->vertex_attribs = ARENA_ALLOC(arena, GLVertexAttrib, num_attribs);
+
+	GLchar attrib_name[256] = {0} ;
 	GLsizei length;
 	GLint size;
 	GLenum type;
 
-	for (int i = 0; i < active_attribs; i++) {
+	for (int i = 0; i < num_attribs; i++) {
 		glGetActiveAttrib(s->prog_id, i, sizeof(attrib_name),
 							&length, &size, &type, attrib_name);
 		GLint location = glGetAttribLocation(s->prog_id, attrib_name);
 		printf("attrib idx: %d, location: %d, type: %s, name: %s \n",
 				i, location, glEnumToString(type), attrib_name);
 
-		// TODO: create a gl_buffer for each vertex attrib...
-		// TODO: store attrib location on attrib struct
+		GLVertexAttrib* attrib = &s->vertex_attribs[i];
+		attrib->data_type = type;
+		attrib->location = location;
+		attrib->name = arenaCopyCStr(arena, attrib_name, sizeof(attrib_name));
 		// TODO: replace POSITION, NORMAL, UV... etc enums in loadGLMesh()
 		// 	with extra logic to detect mesh to shader mapping
+		// TODO: we still need a way to map the shader attribute name to a
+		// 	vertex buffer object... could maybe pass in an array of mappings to
+		// 	loadGLMesh? ie) [{ "position", gm.vert_buf_id }, ...]
 	}
 
 	printf("---------------------------------\n\n");

src/shader.h

@@ -18,6 +18,17 @@ struct gl_buffer
 	char* name;
 };
 
+// NOTE: we need another struct for vertex attributes that mirrors gl_buffer
+// 	because an attribute is associated with a shader_programe while a buffer is
+// 	associated with the vertex data passed to glBufferData()
+struct GLVertexAttrib
+{
+	GLenum data_type;
+	u32 num_components;
+	GLuint location;
+	char* name;
+};
+
 struct gl_uniform
 {
 	// NOTE: would be nice to use idx as the location parameter because it seems
@@ -53,9 +64,8 @@ struct shader_program
 	u32 num_uniforms;
 	gl_uniform* uniforms;
 
-	// FIXME: better name would be vertex_attribs
-	u32 num_buffers;
-	gl_buffer* buffers;
+	u32 num_vertex_attribs;
+	GLVertexAttrib* vertex_attribs;
 
 	char* name;
 	u64 hash; // NOTE: hash of vs filpath + fs filepath concat