X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=effect_chain.h;h=f0138a99d48bd5a6783f6357229f37fa3d5b03d7;hp=7731b54ad5458db41988f0f1d39e2a8b47ae5802;hb=c8ddccde29b5dd2c207cc67fa8af2707904557d8;hpb=1ca4785183b5af9a2a255bba0a28dfdae156470a

diff --git a/effect_chain.h b/effect_chain.h
index 7731b54..f0138a9 100644
--- 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()
 	{
@@ -149,14 +175,30 @@ 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 +206,30 @@ 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;
 };