void render_scene(const Camera& cam, bool skybox_enabled, char render_type) {
glClear(GL_DEPTH_BUFFER_BIT);
glViewport(0, 0, cam.width, cam.height);
glm::mat4 view_proj_mat = compute_mvp_matrix(cam);
// Draw the skybox first.
skybox_shader.update_uniform("enabled", (GLuint)skybox_enabled);
skybox_shader.update_uniform("world_to_cam", view_proj_mat);
skybox_shader.update_uniform("cube_texture", skybox_texture_index);
// Skybox should follow the camera.
skybox_scene_object.transformation = glm::translate(cam.position);
glDepthMask(GL_FALSE);
skybox_shader.render_all(render_type);
glDepthMask(GL_TRUE);
phong.update_uniform("cam_pos", cam.position);
phong.update_uniform("world_to_cam", view_proj_mat);
color_direct.update_uniform("world_to_cam", view_proj_mat);
points.update_uniform("world_to_cam", view_proj_mat);
points.render_all(render_type);
color_direct.render_all(render_type);
phong.render_all(render_type);
}
void render_all(const Camera& main_cam) {
phong.update_uniform("shadows_enabled", (GLuint)shadows_enabled);
// Compute shadow maps by rendering to textures from light perspectives.
for (unsigned int i = 0; i < lights.size(); i++) {
std::string ind_s = "[" + std::to_string(i) + "]";
phong.update_uniform("light_pos" + ind_s, lights[i].first->position);
if (shadows_enabled) {
lights[i].second.bind_for_writing();
Camera light_cam;
light_cam.position = lights[i].first->position;
light_cam.direction = glm::vec3(0, 0, 1);
light_cam.fov = 0.35f;
light_cam.width = lights[i].second.width;
light_cam.height = lights[i].second.height;
light_cam.up = glm::vec3(0, 1, 0);
glm::mat4 light_mvp = compute_mvp_matrix(light_cam);
// It's harmless to set these uniforms here.
phong.update_uniform("world_to_light" + ind_s, light_mvp);
phong.update_uniform("shadow_map" + ind_s, lights[i].second.texture_unit - GL_TEXTURE0);
render_scene(light_cam, false, RENDER_SHADOW);
}
}
// Render to the main screen.
glBindFramebuffer(GL_FRAMEBUFFER, 0);
if (shadows_enabled) {
phong.update_uniform("light_count", (GLuint)lights.size());
for (auto& pair : lights) {
pair.second.bind_for_reading();
}
}
render_scene(main_cam, skybox_enabled, RENDER_MAIN);
// Render to any targets, e.g. vision.
if (offscreen_enabled) {
for (auto& target : render_targets) {
void *data = target.render_buffer.get_data();
target.image_callback((unsigned char *)data, &target.acq_time);
target.render_buffer.data_cleanup();
}
for (auto& target : render_targets) {
target.render_buffer.bind_for_writing();
render_scene(*target.cam, skybox_enabled, RENDER_OFFSCREEN);
// Store the time the image was acquired.
clock_gettime(CLOCK_REALTIME, &target.acq_time);
// Initiate GPU to CPU DMA transfer!
target.render_buffer.bind_for_reading();
}
}
}
glm::mat4 compute_mvp_matrix(const Camera& cam) {
return compute_mvp_matrix(cam.position, cam.direction, cam.up,
(float)cam.width / cam.height, cam.fov);
}
