+// GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
+std::string replace_prefix(const std::string &text, const std::string &prefix)
+{
+ std::string output;
+ size_t start = 0;
+
+ while (start < text.size()) {
+ size_t pos = text.find("PREFIX(", start);
+ if (pos == std::string::npos) {
+ output.append(text.substr(start, std::string::npos));
+ break;
+ }
+
+ output.append(text.substr(start, pos - start));
+ output.append(prefix);
+ output.append("_");
+
+ pos += strlen("PREFIX(");
+
+ // Output stuff until we find the matching ), which we then eat.
+ int depth = 1;
+ size_t end_arg_pos = pos;
+ while (end_arg_pos < text.size()) {
+ if (text[end_arg_pos] == '(') {
+ ++depth;
+ } else if (text[end_arg_pos] == ')') {
+ --depth;
+ if (depth == 0) {
+ break;
+ }
+ }
+ ++end_arg_pos;
+ }
+ output.append(text.substr(pos, end_arg_pos - pos));
+ ++end_arg_pos;
+ assert(depth == 0);
+ start = end_arg_pos;
+ }
+ return output;
+}
+
+void EffectChain::finalize()
+{
+ // TODO: If we want a non-sRGB output color space, convert.
+
+ if (current_gamma_curve != output_format.gamma_curve) {
+ if (current_gamma_curve != GAMMA_LINEAR) {
+ normalize_to_linear_gamma();
+ }
+ assert(current_gamma_curve == GAMMA_LINEAR);
+ GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
+ gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
+ effects.push_back(gamma_conversion);
+ current_gamma_curve = output_format.gamma_curve;
+ }
+
+ std::string frag_shader = read_file("header.glsl");
+
+ for (unsigned i = 0; i < effects.size(); ++i) {
+ char effect_id[256];
+ sprintf(effect_id, "eff%d", i);
+
+ frag_shader += "\n";
+ frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
+ frag_shader += replace_prefix(effects[i]->output_convenience_uniforms(), effect_id);
+ frag_shader += replace_prefix(effects[i]->output_glsl(), effect_id);
+ frag_shader += "#undef PREFIX\n";
+ frag_shader += "#undef FUNCNAME\n";
+ frag_shader += "#undef LAST_INPUT\n";
+ frag_shader += std::string("#define LAST_INPUT ") + effect_id + "\n";
+ frag_shader += "\n";
+ }
+ frag_shader.append(read_file("footer.glsl"));
+ printf("%s\n", frag_shader.c_str());
+
+ glsl_program_num = glCreateProgram();
+ GLhandleARB vs_obj = compile_shader(read_file("vs.glsl"), GL_VERTEX_SHADER);
+ GLhandleARB fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
+ glAttachShader(glsl_program_num, vs_obj);
+ check_error();
+ glAttachShader(glsl_program_num, fs_obj);
+ check_error();
+ glLinkProgram(glsl_program_num);
+ check_error();
+
+ finalized = true;
+}
+
+void EffectChain::render_to_screen(unsigned char *src)
+{
+ assert(finalized);
+
+ check_error();
+ glUseProgram(glsl_program_num);
+ check_error();
+
+ glActiveTexture(GL_TEXTURE0);
+ glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
+
+ GLenum internal_format = GL_RGBA8;
+ if (use_srgb_texture_format) {
+ internal_format = GL_SRGB8;
+ }
+
+ if (input_format.pixel_format == FORMAT_RGB) {
+ glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, src);
+ } else if (input_format.pixel_format == FORMAT_RGBA) {
+ glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, src);
+ } else {
+ assert(false);
+ }
+ check_error();
+ glUniform1i(glGetUniformLocation(glsl_program_num, "input_tex"), 0);
+
+ for (unsigned i = 0; i < effects.size(); ++i) {
+ char effect_id[256];
+ sprintf(effect_id, "eff%d", i);
+ effects[i]->set_uniforms(glsl_program_num, effect_id);
+ }
+
+ glDisable(GL_BLEND);
+ check_error();
+ glDisable(GL_DEPTH_TEST);
+ check_error();
+ glDepthMask(GL_FALSE);
+ check_error();
+
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
+
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+
+ glBegin(GL_QUADS);
+
+ glTexCoord2f(0.0f, 1.0f);
+ glVertex2f(0.0f, 0.0f);
+
+ glTexCoord2f(1.0f, 1.0f);
+ glVertex2f(1.0f, 0.0f);
+
+ glTexCoord2f(1.0f, 0.0f);
+ glVertex2f(1.0f, 1.0f);
+
+ glTexCoord2f(0.0f, 0.0f);
+ glVertex2f(0.0f, 1.0f);
+
+ glEnd();
+ check_error();
+}