Fix up load_program so it can be used for other programs too.

1 files changed, 41 insertions, 17 deletions

diff --git a/glass.c b/glass.c
index e86d28f..3e9cdd2 100644
--- a/glass.c
+++ b/glass.c
@@ -80,6 +80,7 @@ struct uniform_desc {
 	[UNIFORM_F0] = { "F0" },
 };
 
+static GLuint glass_prog = 0;
 struct revolved_object ring;
 GLuint normalmap_tex, heightmap_tex;
 
@@ -232,10 +233,23 @@ install_transform(int instance)
 }
 
 static void
-draw(void)
+draw_rings(void)
 {
 	int instance;
 
+	if (glass_prog != 0) {
+		glUseProgram(glass_prog);
+		glBindVertexArray(ring.array_obj);
+		for (instance = 0; instance < 27; instance++) {
+			install_transform(instance);
+			do_ring_drawelements();
+		}
+	}
+}
+
+static void
+draw(void)
+{
 	glClearColor(0.0, 0.0, 0.8, 0.0);
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
@@ -244,14 +258,9 @@ draw(void)
 
 	update_light_position();
 
-	glBindVertexArray(ring.array_obj);
-
 	glViewport(0, 0, win_width, win_height);
 
-	for (instance = 0; instance < 27; instance++) {
-		install_transform(instance);
-		do_ring_drawelements();
-	}
+	draw_rings();
 
 	SDL_GL_SwapBuffers();
 	frames++;
@@ -635,14 +644,17 @@ generate_rounded_rect_verts(float w, float h, float top_flat, float side_flat,
 	*out_num_verts = num_verts;
 }
 
-static void
-load_program(void)
+static GLuint
+load_program(char *base_filename)
 {
 	GLint prog, fs, vs, ok;
-	int i;
+	char vert_filename[100];
+	char frag_filename[100];
 
-	vs = compile_program(GL_VERTEX_SHADER, "glass.vert");
-	fs = compile_program(GL_FRAGMENT_SHADER, "glass.frag");
+	sprintf(vert_filename, "%s.vert", base_filename);
+	sprintf(frag_filename, "%s.frag", base_filename);
+	vs = compile_program(GL_VERTEX_SHADER, vert_filename);
+	fs = compile_program(GL_FRAGMENT_SHADER, frag_filename);
 	prog = glCreateProgram();
 	glAttachShader(prog, fs);
 	glAttachShader(prog, vs);
@@ -658,13 +670,25 @@ load_program(void)
 		glGetProgramInfoLog(prog, size, NULL, info);
 		fprintf(stderr, "Failed to link: %s\n", info);
 	}
-	glUseProgram(prog);
+	return prog;
+}
 
+static void
+load_programs(void)
+{
+	int i;
+
+	if (glass_prog != 0) {
+		glDeleteProgram(glass_prog);
+	}
+
+	glass_prog = load_program("glass");
+
+	glUseProgram(glass_prog);
 	for (i = 0; i < ARRAY_SIZE(uniforms); i++) {
-		uniforms[i].location = glGetUniformLocation(prog,
+		uniforms[i].location = glGetUniformLocation(glass_prog,
 							    uniforms[i].name);
 	}
-
 	glUniform1i(uniforms[UNIFORM_NORMAL_SAMPLER].location, 0);
 	glUniform1i(uniforms[UNIFORM_HEIGHTMAP_SAMPLER].location, 1);
 
@@ -739,7 +763,7 @@ init(void)
 
 	free(verts);
 
-	load_program();
+	load_programs();
 
 	glActiveTexture(GL_TEXTURE0);
 	normalmap_tex = load_texture_rgb("normalmap.png");
@@ -787,7 +811,7 @@ key(SDLKey sym)
 {
 	switch (sym) {
 	case 'c':
-		load_program();
+		load_programs();
 		break;
 	case 'f':
 		SDL_WM_ToggleFullScreen(sdl_surf);