+ struct Phase;
+
+ // A node in the graph; basically an effect and some associated information.
+ struct Node {
+ Effect *effect;
+
+ // Identifier used to create unique variables in GLSL.
+ std::string effect_id;
+
+ // Edges in the graph (forward and backward).
+ std::vector<Node *> outgoing_links;
+ std::vector<Node *> incoming_links;
+
+ // If output goes to RTT (otherwise, none of these are set).
+ // The Phsae pointer is a but ugly; we should probably fix so
+ // that Phase takes other phases as inputs, instead of Node.
+ GLuint output_texture;
+ unsigned output_texture_width, output_texture_height;
+ Phase *phase;
+
+ // Used during the building of the effect chain.
+ ColorSpace output_color_space;
+ GammaCurve output_gamma_curve;
+ };
+
+ // A rendering phase; a single GLSL program rendering a single quad.
+ struct Phase {
+ GLint glsl_program_num;
+ bool input_needs_mipmaps;
+
+ // Inputs are only inputs from other phases (ie., those that come from RTT);
+ // input textures are not counted here.
+ std::vector<Node *> inputs;
+
+ std::vector<Node *> effects; // In order.
+ unsigned output_width, output_height;
+ };
+
+ // Determine the preferred output size of a given phase.
+ // Requires that all input phases (if any) already have output sizes set.
+ void find_output_size(Phase *phase);
+
+ void find_all_nonlinear_inputs(Node *effect,
+ std::vector<Node *> *nonlinear_inputs,
+ std::vector<Node *> *intermediates);
+ Node *normalize_to_linear_gamma(Node *input);
+ Node *normalize_to_srgb(Node *input);
+
+ void draw_vertex(float x, float y, const std::vector<Effect *> &inputs);
+
+ // Create a GLSL program computing the given effects in order.
+ Phase *compile_glsl_program(const std::vector<Node *> &inputs,
+ const std::vector<Node *> &effects);
+
+ // Create all GLSL programs needed to compute the given effect, and all outputs
+ // that depends on it (whenever possible).
+ void construct_glsl_programs(Node *output);