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:
Phase *phase;
// Used during the building of the effect chain.
- ColorSpace output_color_space;
+ Colorspace output_color_space;
GammaCurve output_gamma_curve;
+ AlphaType output_alpha_type;
friend class EffectChain;
};
// 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);
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.
}
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();
+ 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()) {
// 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();
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;
+ GLenum format;
+ unsigned bytes_per_pixel, num_dither_bits;
bool finalized;
};