add debug shader for vertex normals

src/main.cpp

@@ -1,4 +1,5 @@
 
+#include <cassert>
 #include <cstring>
 #include <iostream>
 
@@ -230,6 +231,42 @@ initGraphics(SDLHandles* handles)
 	return handles->window != nullptr;
 }
 
+bool
+addShaders(RenderState* rs)
+{
+	if (!addShaderProgram(rs->arena,
+			rs->gl_ctx,
+			"../data/shader.vert",
+			"../data/shader.frag",
+			"default"))
+	{
+		LOG(Error) << "error loading default shader\n";
+		return false;
+	}
+
+	if (!addShaderProgram(rs->arena,
+			rs->gl_ctx,
+			"../data/colored_vertices.vert",
+			"../data/colored_vertices.frag",
+			"colored_vertices"))
+	{
+		LOG(Error) << "error loading colored_vertices shader\n";
+		return false;
+	}
+
+	if (!addShaderProgram(rs->arena,
+			rs->gl_ctx,
+			"../data/debug.vert",
+			"../data/debug.frag",
+			"debug"))
+	{
+		LOG(Error) << "error loading debug shader\n";
+		return false;
+	}
+
+	return true;
+}
+
 bool
 loadScene(RenderState* rs)
 {
@@ -242,10 +279,10 @@ loadScene(RenderState* rs)
 		glm::vec3( 10, -10,  0),
 	};
 
-	// TODO: load debug shader from libTangerine for textured_cube
-	shader_program* s = getShaderByName("default", rs->gl_ctx);
+	shader_program* s_default = getShaderByName("default", rs->gl_ctx);
+	shader_program* s_debug = getShaderByName("debug", rs->gl_ctx);
 
-	if (!s)
+	if (!s_default || !s_debug)
 		return false;
 
 	// TODO: full lighting model
@@ -254,7 +291,7 @@ loadScene(RenderState* rs)
 	GLmesh* texmesh = getFreeGLMesh(rs);
 
 	if (texmesh) {
-		*texmesh = loadGLMesh(s, tex_cube->meshes[0],
+		*texmesh = loadGLMesh(s_debug, tex_cube->meshes[0],
 					GL_TRIANGLES, glm::vec3(0, 0, 0));
 		*texmesh->model_xform = glm::mat4(1.f);
 
@@ -271,7 +308,7 @@ loadScene(RenderState* rs)
 		if (!gmesh)
 			return false;
 
-		*gmesh = loadGLMesh(s, cube, GL_TRIANGLES, cube_locs[i]);
+		*gmesh = loadGLMesh(s_default, cube, GL_TRIANGLES, cube_locs[i]);
 
 		if (gmesh->vao_id == 0)
 			return false;
@@ -343,25 +380,13 @@ main()
 		gl_buffer& ubo = rs->gl_ctx->uniform_buffers[rs->gl_ctx->num_ubos++];
 		initTransforms(arena, rs->xforms, &ubo, rs->gl_ctx);
 
-		if (!addShaderProgram(arena,
-				rs->gl_ctx,
-				"../data/shader.vert",
-				"../data/shader.frag",
-				"default"))
-		{
+		if (!addShaders(rs)) {
 			LOG(Error) << "error loading shaders\n";
 			return 1;
 		}
 
-		if (!addShaderProgram(arena,
-				rs->gl_ctx,
-				"../data/colored_vertices.vert",
-				"../data/colored_vertices.frag",
-				"colored_vertices"))
-		{
-			LOG(Error) << "error loading shaders\n";
-			return 1;
-		}
+		shader_program* s_debug = getShaderByName("debug", rs->gl_ctx);
+		dumpShader(s_debug->prog_id);
 
 		if (!loadScene(rs)) {
 			LOG(Error) << "error loading scene\n";

src/shader.cpp

@@ -82,7 +82,9 @@ addShaderProgram(memory_arena* arena,
 			// NOTE: need to set context maximums after at least one shader has
 			// 	been linked
 			initCTXSizes(gl_ctx);
+#if 0
 			dumpShader(s->prog_id);
+#endif
 			s->model_xform_id = glGetUniformLocation(s->prog_id, "model_xform");
 			glDetachShader(s->prog_id, vs_id);
 			glDetachShader(s->prog_id, fs_id);
@@ -376,6 +378,17 @@ loadGLMesh(shader_program* s,
 	glVertexAttribPointer(POSITION, 3, GL_FLOAT, GL_FALSE, 0, 0);
 	glEnableVertexAttribArray(POSITION);
 
+	if (m.normals != nullptr) {
+		glGenBuffers(1, &gm.norm_buf_id);
+		glBindBuffer(GL_ARRAY_BUFFER, gm.norm_buf_id);
+		glBufferData(GL_ARRAY_BUFFER,
+			m.num_vertices * 3 * sizeof(GLfloat),
+			m.normals,
+			GL_STATIC_DRAW);
+		glVertexAttribPointer(NORMAL, 3, GL_FLOAT, GL_FALSE, 0, 0);
+		glEnableVertexAttribArray(NORMAL);
+	}
+
 	glGenBuffers(1, &gm.idx_buf_id);
 	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, gm.idx_buf_id);
 	glBufferData(GL_ELEMENT_ARRAY_BUFFER,