allow entities to have empty diffuse texture

this is needed when we want to programatticaly create meshes for use
with, eg) the colored_vertices shader.

src/entity.cpp

@@ -19,16 +19,19 @@ initEntity(Entity* e,
 	e->model_xform = ARENA_ALLOC(arena, glm::mat4, 1);
 	*e->model_xform = glm::mat4(1.f);
 	e->name = arenaCopyCStr(arena, name);
-	e->diffuse_texture = getGLTexture(gl_ctx, mdl->diffuse_texture);
 
-	if (!e->diffuse_texture)
-		return false;
+	if (mdl->diffuse_texture) {
+		e->diffuse_texture = getGLTexture(gl_ctx, mdl->diffuse_texture);
+
+		if (!e->diffuse_texture)
+			return false;
+	}
 
 	for (u32 i = 0; i< e->num_meshes; i++) {
 		GLMesh* glm = &e->meshes[i];
 		*glm = loadGLMesh(mdl->meshes[i],
 					GL_TRIANGLES,
-					e->diffuse_texture->id,
+					e->diffuse_texture,
 					num_attrib_mappings,
 					attrib_mappings);
 

src/main.cpp

@@ -56,40 +56,7 @@ loadLights(RenderState* rs)
 }
 
 bool
-loadSpaceShip(RenderState* rs)
-{
-	Model* ship = getModelByPath(&rs->assets, "../data/spaceship.gltf");
-	if (!ship)
-		return false;
-
-	ShaderProgram* shader_lit = getShaderByName("full_lighting", rs->gl_ctx);
-	if (!shader_lit)
-		return false;
-
-	// load model into gl
-	RenderGroup* rg = getFreeRenderGroup(rs);
-	assert(rs);
-	initRenderGroup(rg, rs->rg_arena, shader_lit, 256, "ships");
-	Entity* e = getFreeEntity(rg);
-	assert(e);
-
-	if (initEntity(e, rs->gl_ctx,
-					rs->rg_arena,
-					ship,
-					shader_lit->num_vertex_attribs,
-					shader_lit->attrib_mappings,
-					"ship 01"))
-	{
-		setEntityPosition(e, glm::vec3(0, -10, -15));
-	} else {
-		return false;
-	}
-
-	return true;
-}
-
-bool
-loadScene(RenderState* rs)
+loadCubes(RenderState* rs)
 {
 	// NOTE: load model
 	Model* tex_cube = getModelByPath(&rs->assets, "../data/textured_cube.gltf");
@@ -124,7 +91,6 @@ loadScene(RenderState* rs)
 		char cube_name[256] = {0};
 		snprintf(cube_name, 256, "textured_cube%d", i);
 
-		arenaCopyCStr(rs->rg_arena, cube_name);
 		if (!initEntity(e,
 				rs->gl_ctx,
 				rs->rg_arena,
@@ -140,8 +106,115 @@ loadScene(RenderState* rs)
 		scaleEntity(e, 3);
 	}
 
-	// NOTE: testing an entity with multiple meshes
-#if 0
+	return true;
+}
+
+// NOTE: test an entity with multiple meshes
+bool
+loadSpaceShip(RenderState* rs)
+{
+	Model* ship = getModelByPath(&rs->assets, "../data/spaceship.gltf");
+	if (!ship)
+		return false;
+
+	ShaderProgram* shader_lit = getShaderByName("full_lighting", rs->gl_ctx);
+	if (!shader_lit)
+		return false;
+
+	// load model into gl
+	RenderGroup* rg = getFreeRenderGroup(rs);
+	assert(rs);
+	initRenderGroup(rg, rs->rg_arena, shader_lit, 256, "ships");
+	Entity* e = getFreeEntity(rg);
+	assert(e);
+
+	if (initEntity(e, rs->gl_ctx,
+					rs->rg_arena,
+					ship,
+					shader_lit->num_vertex_attribs,
+					shader_lit->attrib_mappings,
+					"ship 01"))
+	{
+		setEntityPosition(e, glm::vec3(0, -10, -15));
+	} else {
+		return false;
+	}
+
+	return true;
+}
+
+bool
+testColoredVertices(RenderState* rs)
+{
+	Mesh m = {0};
+	m.num_vertices = 5;
+	m.num_indices = 12;
+
+	glm::vec3 vertices[m.num_vertices] = {
+		{  0,  1,  0   },
+		{ -1, -1, -1   },
+		{ -1, -1,  1   },
+		{  1, -1,  0.5 },
+	};
+
+	u16 indices[m.num_indices] = {
+		0, 1, 2,
+		0, 2, 3,
+		0, 3, 1,
+		1, 2, 3
+	};
+
+	glm::vec3 colors[m.num_vertices] = {
+		{ 1, 0, 0 },
+		{ 0, 1, 0 },
+		{ 0, 0, 1 },
+		{ 1, 1, 0 }
+	};
+
+	m.vertices = vertices;
+	m.colors = colors;
+	m.indices = indices;
+	glm::mat4 xform = glm::mat4(1);
+	m.xform = &xform;
+	Model mdl = {0};
+	mdl.num_meshes = 1;
+	mdl.meshes = &m;
+
+	ShaderProgram* shader = getShaderByName("colored_vertices", rs->gl_ctx);
+	RenderGroup* rg = getFreeRenderGroup(rs);
+	assert(shader && rg);
+	initRenderGroup(rg, rs->rg_arena, shader, 256, "colored_pyramids");
+	Entity* e = getFreeEntity(rg);
+	assert(e);
+
+	if (initEntity(e, rs->gl_ctx,
+					rs->rg_arena,
+					&mdl,
+					shader->num_vertex_attribs,
+					shader->attrib_mappings,
+					"colored pyramid 01"))
+	{
+		setEntityPosition(e, glm::vec3(0, -10, 15));
+	} else {
+		return false;
+	}
+
+	return true;
+}
+
+bool
+loadScene(RenderState* rs)
+{
+	if (!loadCubes(rs)) {
+		LOGF(Error, "Error loading cubes\n");
+		return false;
+	}
+
+	if (!testColoredVertices(rs)) {
+		LOGF(Error, "Error loading colored vertices\n");
+		return false;
+	}
+#if 1
 	if (!loadSpaceShip(rs))
 		return false;
 #endif

src/shader.cpp

@@ -235,15 +235,15 @@ void
 renderVAO(GLMesh* glmesh,
 	glm::mat4* node_xform,
 	ShaderProgram* shader,
-	GLuint tex_id)
+	GLTexture* gl_tex)
 {
 	glUseProgram(shader->prog_id);
 	glBindVertexArray(glmesh->vao_id);
 	glUniformMatrix4fv(shader->node_xform_id, 1, GL_FALSE,
 		(float*) node_xform);
 
-	if (tex_id > 0) {
-		glBindTexture(GL_TEXTURE_2D, tex_id);
+	if (glmesh->has_texture) {
+		glBindTexture(GL_TEXTURE_2D, gl_tex->id);
 		glUniform1i(shader->sampler_id, 0);
 	}
 
@@ -324,14 +324,19 @@ initGLAttribBuffer(GLBuffer* buf, GLenum target, GLVertexAttrib* attrib)
 GLMesh
 loadGLMesh(const Mesh& m,
 	GLenum draw_mode,
-	GLuint diffuse_texture_id,
+	GLTexture* diffuse_texture,
 	u32 num_mappings,
 	GLBufferToAttribMapping mappings[])
 {
 	// NOTE: need to use freeGLMesh() when freeing because we're not storing
 	// 	the GLBuffers on a memory arean (yet)
 	GLMesh glm = initGLMesh(m, num_mappings, draw_mode);
-	glm.tex_id = diffuse_texture_id;
+
+	if (diffuse_texture) {
+		glm.has_texture = true;
+		glm.tex_id = diffuse_texture->id;
+	}
+
 	glGenVertexArrays(1, &glm.vao_id);
 	glBindVertexArray(glm.vao_id);
 

src/shader.h

@@ -129,6 +129,7 @@ struct GLMesh
 {
 	u32 num_indices;
 	GLuint vao_id;
+	bool has_texture;
 	GLuint tex_id;
 	GLenum draw_mode; // NOTE: GL_LINES, GL_TRIANGLES
 	GLenum usage; // NOTE: GL_STATIC_DRAW, GL_DYNAMIC_DRAW
@@ -188,13 +189,13 @@ void updateGLBuffer(GLBuffer* gl_buf, void* data);
 void renderVAO(GLMesh* glmesh,
 	glm::mat4* node_xform,
 	ShaderProgram* shader,
-	GLuint tex_id = 0);
+	GLTexture* gl_tex);
 
 GLVertexAttrib* getVertexAttribByName(ShaderProgram* shader, const char* name);
 
 GLMesh loadGLMesh(const Mesh& m,
 	GLenum draw_mode,
-	GLuint diffuse_texture_id,
+	GLTexture* diffuse_texture,
 	u32 num_mappings,
 	GLBufferToAttribMapping mappings[]);
 

src/tangerine.cpp

@@ -196,7 +196,7 @@ renderFrame(RenderState* rs, const GLClearColor& clear_col)
 			for (u32 k = 0; k < e->num_meshes; k++) {
 				GLMesh& glm = e->meshes[k];
 				renderVAO(&glm, e->model_xform, rg->shader,
-							e->diffuse_texture->id);
+							e->diffuse_texture);
 			}
 		}
 	}

src/tangerine.h

@@ -57,6 +57,7 @@
 *  - test complex entities
 *  		- need a separate GLBufferToAttribMapping for each mesh on an entity
 *  		- maybe fixed now with MeshBufferType enum and getMeshData()
+*  - allow entities to have an empty diffuse texture (see initEntity())
 */