void draw_scene(App *app)
{
int n = 5;
for (int zi = 0; zi <= n; zi++)
for (int xi = 0; xi <= n; xi++)
{
float x = Centimeter(-100.0f) + 2.0f * Centimeter(100.0f * xi / n);
float z = Centimeter(-100.0f * zi);
int i = zi * n + xi;
mat4 mat_model = translate(x, 0.0f, z) *
scale(Centimeter(5.0f)) *
rotateY(0.3f * app->elapsed_time + i * 1.57f) *
rotateX(0.2f * app->elapsed_time + i * 3.2f);
uniformm4(cube, model, mat_model);
GL_CHECK(glDrawArrays(GL_TRIANGLES, 0, 36));
}
mat4 mat_model = translate(0.0f, Centimeter(70.0f), Centimeter(400.0f)) *
scale(Centimeter(5.0f)) *
rotateY(0.3f * app->elapsed_time) *
rotateX(0.05f * app->elapsed_time);
uniformm4(cube, model, mat_model);
GL_CHECK(glDrawArrays(GL_TRIANGLES, 0, 36));
}
void app_update_and_render(App *app)
{
app->current_scene = (int)(app->elapsed_time / 20.0f) % NUM_SCENES;
Scene scene = app->scenes[app->current_scene];
float model_scale = animate_model_scale(app->elapsed_time);
float aspect_ratio = app->window_width / (float)app->window_height;
mat4 mat_projection = perspective(scene.fov, aspect_ratio, scene.z_near, scene.z_far);
mat4 mat_cube_model = rotateX(PI / 2.0f) * scale(model_scale);
mat4 mat_view = animate_camera(app->elapsed_time);
glEnable(GL_CULL_FACE);
glFrontFace(GL_CCW);
glCullFace(GL_BACK);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glEnable(GL_DEPTH_TEST);
glDepthMask(GL_TRUE);
glDepthRangef(0.0, 1.0);
glClearDepthf(1.0f);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glBlendEquation(GL_FUNC_ADD);
////////////////
// Draw backdrop
glDepthMask(GL_FALSE);
glUseProgram(app->program_backdrop);
glBindBuffer(GL_ARRAY_BUFFER, app->vbo_quad);
attribfv(backdrop, position, 2, 0);
uniform3fv(backdrop, sun_dir, scene.sun_dir);
uniform2f(backdrop, screen_size, app->window_width, app->window_height);
uniform1f(backdrop, inv_tan_fov, 1.0f / (scene.fov / 2.0f));
uniformm4(backdrop, view, mat_view);
glDrawArrays(GL_TRIANGLES, 0, 6);
glDepthMask(GL_TRUE);
//////////////////////////
// Draw tessellated sphere
glUseProgram(app->program_mapping);
glBindBuffer(GL_ARRAY_BUFFER, app->vbo_cube);
attribfv(mapping, position, 3, 0);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_CUBE_MAP, scene.heightmap);
uniform1i(mapping, heightmap, 0);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_CUBE_MAP, scene.diffusemap);
uniform1i(mapping, diffusemap, 1);
uniform1f(mapping, height_scale, scene.height_scale);
uniform1f(mapping, use_mip, scene.use_mip ? 1.0f : 0.0f);
uniform1f(mapping, max_lod_coverage, scene.max_lod_coverage);
uniform2f(mapping, screen_size, app->window_width, app->window_height);
uniformm4(mapping, model, mat_cube_model);
uniformm4(mapping, view, mat_view);
uniformm4(mapping, projection, mat_projection);
glPatchParameteri(GL_PATCH_VERTICES, VERTICES_PER_PATCH);
glDrawArrays(GL_PATCHES, 0, NUM_PATCHES * VERTICES_PER_PATCH);
}