add option to specify GL usage in initGLFloatBuffer()

src/render_object.cpp

@@ -46,7 +46,10 @@ void drawSimple(render_objects* r_objs,
 	shader_wrapper sw,
 	light_group* lights);
 inline void enableGLFloatBuffer(uint buffer_id, uint location);
-bool initGLFloatBuffer(glm::vec3* buffer, uint count, GLuint& buffer_id);
+bool initGLFloatBuffer(glm::vec3* buffer,
+		uint count,
+		GLuint& buffer_id,
+		GLenum usage = GL_STATIC_DRAW);
 bool initGLIndexBuffer(uint* buffer, uint num_indices, GLuint& buffer_id);
 bool initGLTexture(const util_image image, GLuint& tex_id);
 bool loadMeshIntoGL(default_render_object* ro_out, mesh_info* mi_in);
@@ -93,10 +96,12 @@ roInitSimpleMesh(simple_mesh& mesh_in, GLenum draw_mode)
 
 	if (initGLFloatBuffer(mesh_in.vertices,
 			mesh_in.num_vertices,
-			objects->vertex_buffer_id) &&
+			objects->vertex_buffer_id,
+			GL_DYNAMIC_DRAW) &&
 		initGLFloatBuffer(mesh_in.vert_colors,
 			mesh_in.num_vertices,
-			objects->vertex_color_buffer_id))
+			objects->vertex_color_buffer_id,
+			GL_DYNAMIC_DRAW))
 	{
 		objects->model_transform = mesh_in.model_transform;
 		objects->vertex_count = mesh_in.num_vertices;
@@ -158,13 +163,13 @@ roUpdateSimpleMesh(render_objects* r_objs, simple_mesh* mesh, GLenum draw_mode)
 	glBufferSubData(
 		GL_ARRAY_BUFFER,
 		0,
-		sro->vertex_count * sizeof(GLfloat),
+		3 * sro->vertex_count * sizeof(GLfloat),
 		mesh->vertices);
 	glBindBuffer(GL_ARRAY_BUFFER, sro->vertex_color_buffer_id);
 	glBufferSubData(
 		GL_ARRAY_BUFFER,
 		0,
-		sro->vertex_count * sizeof(GLfloat),
+		3 * sro->vertex_count * sizeof(GLfloat),
 		mesh->vert_colors);
 }
 
@@ -238,14 +243,17 @@ enableGLFloatBuffer(uint buffer_id, uint location)
 }
 
 bool
-initGLFloatBuffer(glm::vec3* buffer, uint count, GLuint& buffer_id)
+initGLFloatBuffer(glm::vec3* buffer,
+	uint count,
+	GLuint& buffer_id,
+	GLenum usage)
 {
 	glGenBuffers(1, &buffer_id);
 	glBindBuffer(GL_ARRAY_BUFFER, buffer_id);
 	glBufferData(GL_ARRAY_BUFFER,
 		count * 3 * sizeof(GLfloat), // NOTE: 3 floats per vertex prop
 		buffer,
-		GL_STATIC_DRAW);
+		usage);
 
 	return (glGetError() == GL_NO_ERROR);
 }