Add an implementation of RPDF dither on the final output.

[movit] / effect_chain.h

diff --git a/effect_chain.h b/effect_chain.h
index 48b60872173b283e6eba59c4ad97a2ba782566e3..c38f34749cb89ff2a68fe67b61a62abcc5364983 100644 (file)
--- a/effect_chain.h
+++ b/effect_chain.h
@@ -25,6 +25,13 @@ private:
        // Identifier used to create unique variables in GLSL.
        std::string effect_id;
 
+       // Logical size of the output of this effect, ie. the resolution
+       // you would get if you sampled it as a texture. If it is undefined
+       // (since the inputs differ in resolution), it will be 0x0.
+       // If both this and output_texture_{width,height} are set,
+       // they will be equal.
+       unsigned output_width, output_height;
+
        // If output goes to RTT (otherwise, none of these are set).
        // The Phase pointer is a but ugly; we should probably fix so
        // that Phase takes other phases as inputs, instead of Node.
@@ -33,7 +40,7 @@ private:
        Phase *phase;
 
        // Used during the building of the effect chain.
-       ColorSpace output_color_space;
+       Colorspace output_color_space;
        GammaCurve output_gamma_curve;
 
        friend class EffectChain;
@@ -41,7 +48,7 @@ private:
 
 // A rendering phase; a single GLSL program rendering a single quad.
 struct Phase {
-       GLint glsl_program_num;
+       GLint glsl_program_num, vertex_shader, fragment_shader;
        bool input_needs_mipmaps;
 
        // Inputs are only inputs from other phases (ie., those that come from RTT);
@@ -55,6 +62,7 @@ struct Phase {
 class EffectChain {
 public:
        EffectChain(float aspect_nom, float aspect_denom);  // E.g., 16.0f, 9.0f for 16:9.
+       ~EffectChain();
 
        // User API:
        // input, effects, output, finalize need to come in that specific order.
@@ -82,10 +90,27 @@ public:
        Effect *add_effect(Effect *effect, const std::vector<Effect *> &inputs);
 
        void add_output(const ImageFormat &format);
+
+       // Set number of output bits, to scale the dither.
+       // 8 is the right value for most outputs.
+       // The default, 0, is a special value that means no dither.
+       void set_dither_bits(unsigned num_bits)
+       {
+               this->num_dither_bits = num_bits;
+       }
+
        void finalize();
 
+
        //void render(unsigned char *src, unsigned char *dst);
-       void render_to_screen();
+       void render_to_screen()
+       {
+               render_to_fbo(0, 0, 0);
+       }
+
+       // Render the effect chain to the given FBO. If width=height=0, keeps
+       // the current viewport.
+       void render_to_fbo(GLuint fbo, unsigned width, unsigned height);
 
        Effect *last_added_effect() {
                if (nodes.empty()) {
@@ -111,6 +136,10 @@ private:
        // (aspect_nom/aspect_denom) and returns the new width and height.
        unsigned fit_rectangle_to_aspect(unsigned width, unsigned height);
 
+       // Compute the input sizes for all inputs for all effects in a given phase,
+       // and inform the effects about the results.    
+       void inform_input_sizes(Phase *phase);
+
        // 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);
@@ -149,19 +178,22 @@ private:
        void fix_internal_gamma_by_asking_inputs(unsigned step);
        void fix_internal_gamma_by_inserting_nodes(unsigned step);
        void fix_output_gamma();
+       void add_dither_if_needed();
 
        float aspect_nom, aspect_denom;
        ImageFormat output_format;
 
        std::vector<Node *> nodes;
        std::map<Effect *, Node *> node_map;
+       Effect *dither_effect;
 
        std::vector<Input *> inputs;  // Also contained in nodes.
 
        GLuint fbo;
        std::vector<Phase *> phases;
 
-       GLenum format, bytes_per_pixel;
+       GLenum format;
+       unsigned bytes_per_pixel, num_dither_bits;
        bool finalized;
 };