Fix a bug where intermediate phase outputs could get too low height.

[movit] / effect_chain.h

diff --git a/effect_chain.h b/effect_chain.h
index 7731b54ad5458db41988f0f1d39e2a8b47ae5802..4b277b38d8d8eab6b221dd651a52d2889564cec7 100644 (file)
--- a/effect_chain.h
+++ b/effect_chain.h
@@ -11,6 +11,21 @@
 class EffectChain;
 class Phase;
 
+// For internal use within Node.
+enum AlphaType {
+       ALPHA_INVALID = -1,
+       ALPHA_BLANK,
+       ALPHA_PREMULTIPLIED,
+       ALPHA_POSTMULTIPLIED,
+};
+
+// Whether you want pre- or postmultiplied alpha in the output
+// (see effect.h for a discussion of pre- versus postmultiplied alpha).
+enum OutputAlphaFormat {
+       OUTPUT_ALPHA_PREMULTIPLIED,
+       OUTPUT_ALPHA_POSTMULTIPLIED,
+};
+
 // A node in the graph; basically an effect and some associated information.
 class Node {
 public:
@@ -42,6 +57,7 @@ private:
        // Used during the building of the effect chain.
        Colorspace output_color_space;
        GammaCurve output_gamma_curve;
+       AlphaType output_alpha_type;
 
        friend class EffectChain;
 };
@@ -89,9 +105,19 @@ public:
        }
        Effect *add_effect(Effect *effect, const std::vector<Effect *> &inputs);
 
-       void add_output(const ImageFormat &format);
+       void add_output(const ImageFormat &format, OutputAlphaFormat alpha_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()
        {
@@ -122,9 +148,10 @@ public:
        void insert_node_between(Node *sender, Node *middle, Node *receiver);
 
 private:
-       // Fits a rectangle of the given size to the current aspect ratio
-       // (aspect_nom/aspect_denom) and returns the new width and height.
-       unsigned fit_rectangle_to_aspect(unsigned width, unsigned height);
+       // Make sure the output rectangle is at least large enough to hold
+       // the given input rectangle in both dimensions, and is of the
+       // current aspect ratio (aspect_nom/aspect_denom).
+       void size_rectangle_to_fit(unsigned width, unsigned height, unsigned *output_width, unsigned *output_height);
 
        // Compute the input sizes for all inputs for all effects in a given phase,
        // and inform the effects about the results.    
@@ -149,14 +176,30 @@ private:
        // Output the current graph to the given file in a Graphviz-compatible format;
        // only useful for debugging.
        void output_dot(const char *filename);
+       std::vector<std::string> get_labels_for_edge(const Node *from, const Node *to);
+       void output_dot_edge(FILE *fp,
+                            const std::string &from_node_id,
+                            const std::string &to_node_id,
+                            const std::vector<std::string> &labels);
 
        // Some of the graph algorithms assume that the nodes array is sorted
        // topologically (inputs are always before outputs), but some operations
        // (like graph rewriting) can change that. This function restores that order.
-       void sort_nodes_topologically();
-       void topological_sort_visit_node(Node *node, std::set<Node *> *visited_nodes, std::vector<Node *> *sorted_list);
+       void sort_all_nodes_topologically();
+
+       // Do the actual topological sort. <nodes> must be a connected, acyclic subgraph;
+       // links that go to nodes not in the set will be ignored.
+       std::vector<Node *> topological_sort(const std::vector<Node *> &nodes);
+
+       // Utility function used by topological_sort() to do a depth-first search.
+       // The reason why we store nodes left to visit instead of a more conventional
+       // list of nodes to visit is that we want to be able to limit ourselves to
+       // a subgraph instead of all nodes. The set thus serves a dual purpose.
+       void topological_sort_visit_node(Node *node, std::set<Node *> *nodes_left_to_visit, std::vector<Node *> *sorted_list);
 
        // Used during finalize().
+       void find_color_spaces_for_inputs();
+       void propagate_alpha();
        void propagate_gamma_and_color_space();
        Node *find_output_node();
 
@@ -164,23 +207,30 @@ private:
        void fix_internal_color_spaces();
        void fix_output_color_space();
 
+       bool node_needs_alpha_fix(Node *node);
+       void fix_internal_alpha(unsigned step);
+       void fix_output_alpha();
+
        bool node_needs_gamma_fix(Node *node);
        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;
+       OutputAlphaFormat output_alpha_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;
+       unsigned num_dither_bits;
        bool finalized;
 };