1 files changed, 92 insertions, 0 deletions
diff --git a/draw.h b/draw.h
new file mode 100644
index 0000000..bb67639
--- /dev/null
+++ b/draw.h
@@ -0,0 +1,92 @@
+void clear_window(v3 color)
+{
+	glClearColor(color.x, color.y, color.z, 1.0f);
+	glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
+}
+
+void begin3d(prge_window_t window, shader_t shader, camera_t camera)
+{
+	f32 aspect_ratio = (f32)window.width/(f32)window.height;
+	mat4 projection = perspective(camera, aspect_ratio);
+	mat4 view = camera_get_view_mat(camera);
+
+	glUseProgram(shader.id);
+	shader_set_mat4(shader, SHADER_PROJECTION_MATRIX, projection);
+	shader_set_mat4(shader, SHADER_VIEW_MATRIX, view);
+}
+
+void end3d(void)
+{
+	glUseProgram(0);
+}
+
+void begin3d_alpha(prge_window_t window, shader_t shader, camera_t camera)
+{
+	glEnable(GL_BLEND);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+	begin3d(window, shader, camera);
+}
+
+void end3d_alpha(void)
+{
+	end3d();
+	glDisable(GL_BLEND);
+}
+
+void draw_mesh(mesh_t mesh)
+{
+	if (!mesh.vao) {
+		printf("warning: trying to draw mesh that doesn't have vao\n");
+		return;
+	}
+
+	glBindVertexArray(mesh.vao);
+
+	for (i32 i = 0; i < mesh.ntextures; i++) {
+		glActiveTexture(GL_TEXTURE0+i);
+		glBindTexture(GL_TEXTURE_2D, mesh.textures[i].id);
+	}
+
+	if (mesh.ebo)
+		glDrawElements(GL_TRIANGLES, mesh.nindices, GL_UNSIGNED_INT, 0);
+	else
+		glDrawArrays(GL_TRIANGLES, 0, mesh.nvertices);
+
+	glBindTexture(GL_TEXTURE_2D, 0);
+
+	glBindVertexArray(0);
+} 
+
+void draw_model(shader_t shader, model_t model)
+{
+	mat4 modelmat = apply_transform(model.transform);
+	for (i32 i = 0; i < model.nmeshes; ++i) {
+		mat4 meshmat = apply_transform(model.meshes[i].transform);
+		mat4 resultmat = mat4_mul(modelmat, meshmat);
+
+		shader_set_mat4(shader, SHADER_MODEL_MATRIX, resultmat);
+		draw_mesh(model.meshes[i]);
+	}
+}
+
+void draw_entity(shader_t shader, entity_t entity)
+{
+	v3 position = entity.model.transform.position;
+	position = v3_add(position, entity.position);
+	entity.model.transform.position = position;
+	draw_model(shader, entity.model);
+}
+
+void draw_entities(elist_t entities, shader_t shader)
+{
+	for (enode_t *node = entities.first; node; node = node->next)
+		if (!(node->entity.flags & ENTITY_ALPHA))
+			draw_entity(shader, node->entity);
+}
+
+void draw_entities_alpha(elist_t entities, shader_t shader)
+{
+	for (enode_t *node = entities.first; node; node = node->next)
+		if (node->entity.flags & ENTITY_ALPHA)
+			draw_entity(shader, node->entity);
+}