+void EffectChain::execute_phase(Phase *phase, bool last_phase, map<Phase *, GLuint> *output_textures, set<Phase *> *generated_mipmaps)
+{
+ GLuint fbo = 0;
+
+ // Find a texture for this phase.
+ inform_input_sizes(phase);
+ if (!last_phase) {
+ find_output_size(phase);
+
+ GLuint tex_num = resource_pool->create_2d_texture(GL_RGBA16F, phase->output_width, phase->output_height);
+ output_textures->insert(make_pair(phase, tex_num));
+ }
+
+ const GLuint glsl_program_num = phase->glsl_program_num;
+ check_error();
+ glUseProgram(glsl_program_num);
+ check_error();
+
+ // Set up RTT inputs for this phase.
+ for (unsigned sampler = 0; sampler < phase->inputs.size(); ++sampler) {
+ glActiveTexture(GL_TEXTURE0 + sampler);
+ Phase *input = phase->inputs[sampler];
+ input->output_node->bound_sampler_num = sampler;
+ glBindTexture(GL_TEXTURE_2D, (*output_textures)[input]);
+ check_error();
+ if (phase->input_needs_mipmaps && generated_mipmaps->count(input) == 0) {
+ glGenerateMipmap(GL_TEXTURE_2D);
+ check_error();
+ generated_mipmaps->insert(input);
+ }
+ setup_rtt_sampler(glsl_program_num, sampler, phase->effect_ids[input->output_node], phase->input_needs_mipmaps);
+ }
+
+ // And now the output. (Already set up for us if it is the last phase.)
+ if (!last_phase) {
+ void *context = get_gl_context_identifier();
+ fbo = resource_pool->create_fbo(context, (*output_textures)[phase]);
+ glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+ glViewport(0, 0, phase->output_width, phase->output_height);
+ }
+
+ // Give the required parameters to all the effects.
+ unsigned sampler_num = phase->inputs.size();
+ for (unsigned i = 0; i < phase->effects.size(); ++i) {
+ Node *node = phase->effects[i];
+ unsigned old_sampler_num = sampler_num;
+ node->effect->set_gl_state(glsl_program_num, phase->effect_ids[node], &sampler_num);
+ check_error();
+
+ if (node->effect->is_single_texture()) {
+ assert(sampler_num - old_sampler_num == 1);
+ node->bound_sampler_num = old_sampler_num;
+ } else {
+ node->bound_sampler_num = -1;
+ }
+ }
+
+ glBindVertexArray(phase->vao);
+ check_error();
+ glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+ check_error();
+
+ for (unsigned i = 0; i < phase->effects.size(); ++i) {
+ Node *node = phase->effects[i];
+ node->effect->clear_gl_state();
+ }
+
+ if (!last_phase) {
+ resource_pool->release_fbo(fbo);
+ }
+}
+