1 #ifndef _EFFECT_CHAIN_H
2 #define _EFFECT_CHAIN_H 1
12 #include "image_format.h"
20 // For internal use within Node.
28 // Whether you want pre- or postmultiplied alpha in the output
29 // (see effect.h for a discussion of pre- versus postmultiplied alpha).
30 enum OutputAlphaFormat {
31 OUTPUT_ALPHA_FORMAT_PREMULTIPLIED,
32 OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED,
35 // A node in the graph; basically an effect and some associated information.
41 // Edges in the graph (forward and backward).
42 std::vector<Node *> outgoing_links;
43 std::vector<Node *> incoming_links;
46 // Identifier used to create unique variables in GLSL.
47 std::string effect_id;
49 // Logical size of the output of this effect, ie. the resolution
50 // you would get if you sampled it as a texture. If it is undefined
51 // (since the inputs differ in resolution), it will be 0x0.
52 // If both this and output_texture_{width,height} are set,
53 // they will be equal.
54 unsigned output_width, output_height;
56 // If output goes to RTT (otherwise, none of these are set).
57 // The Phase pointer is a but ugly; we should probably fix so
58 // that Phase takes other phases as inputs, instead of Node.
59 GLuint output_texture;
60 unsigned output_texture_width, output_texture_height;
63 // Used during the building of the effect chain.
64 Colorspace output_color_space;
65 GammaCurve output_gamma_curve;
66 AlphaType output_alpha_type;
68 friend class EffectChain;
71 // A rendering phase; a single GLSL program rendering a single quad.
73 GLint glsl_program_num, vertex_shader, fragment_shader;
74 bool input_needs_mipmaps;
76 // Inputs are only inputs from other phases (ie., those that come from RTT);
77 // input textures are not counted here.
78 std::vector<Node *> inputs;
80 std::vector<Node *> effects; // In order.
81 unsigned output_width, output_height, virtual_output_width, virtual_output_height;
86 EffectChain(float aspect_nom, float aspect_denom); // E.g., 16.0f, 9.0f for 16:9.
90 // input, effects, output, finalize need to come in that specific order.
92 // EffectChain takes ownership of the given input.
93 // input is returned back for convenience.
94 Input *add_input(Input *input);
96 // EffectChain takes ownership of the given effect.
97 // effect is returned back for convenience.
98 Effect *add_effect(Effect *effect) {
99 return add_effect(effect, last_added_effect());
101 Effect *add_effect(Effect *effect, Effect *input) {
102 std::vector<Effect *> inputs;
103 inputs.push_back(input);
104 return add_effect(effect, inputs);
106 Effect *add_effect(Effect *effect, Effect *input1, Effect *input2) {
107 std::vector<Effect *> inputs;
108 inputs.push_back(input1);
109 inputs.push_back(input2);
110 return add_effect(effect, inputs);
112 Effect *add_effect(Effect *effect, const std::vector<Effect *> &inputs);
114 void add_output(const ImageFormat &format, OutputAlphaFormat alpha_format);
116 // Set number of output bits, to scale the dither.
117 // 8 is the right value for most outputs.
118 // The default, 0, is a special value that means no dither.
119 void set_dither_bits(unsigned num_bits)
121 this->num_dither_bits = num_bits;
127 //void render(unsigned char *src, unsigned char *dst);
128 void render_to_screen()
130 render_to_fbo(0, 0, 0);
133 // Render the effect chain to the given FBO. If width=height=0, keeps
134 // the current viewport.
135 void render_to_fbo(GLuint fbo, unsigned width, unsigned height);
137 Effect *last_added_effect() {
141 return nodes.back()->effect;
145 // API for manipulating the graph directly. Intended to be used from
146 // effects and by EffectChain itself.
148 // Note that for nodes with multiple inputs, the order of calls to
149 // connect_nodes() will matter.
150 Node *add_node(Effect *effect);
151 void connect_nodes(Node *sender, Node *receiver);
152 void replace_receiver(Node *old_receiver, Node *new_receiver);
153 void replace_sender(Node *new_sender, Node *receiver);
154 void insert_node_between(Node *sender, Node *middle, Node *receiver);
157 // Make sure the output rectangle is at least large enough to hold
158 // the given input rectangle in both dimensions, and is of the
159 // current aspect ratio (aspect_nom/aspect_denom).
160 void size_rectangle_to_fit(unsigned width, unsigned height, unsigned *output_width, unsigned *output_height);
162 // Compute the input sizes for all inputs for all effects in a given phase,
163 // and inform the effects about the results.
164 void inform_input_sizes(Phase *phase);
166 // Determine the preferred output size of a given phase.
167 // Requires that all input phases (if any) already have output sizes set.
168 void find_output_size(Phase *phase);
170 // Find all inputs eventually feeding into this effect that have
171 // output gamma different from GAMMA_LINEAR.
172 void find_all_nonlinear_inputs(Node *effect, std::vector<Node *> *nonlinear_inputs);
174 // Create a GLSL program computing the given effects in order.
175 Phase *compile_glsl_program(const std::vector<Node *> &inputs,
176 const std::vector<Node *> &effects);
178 // Create all GLSL programs needed to compute the given effect, and all outputs
179 // that depends on it (whenever possible).
180 void construct_glsl_programs(Node *output);
182 // Output the current graph to the given file in a Graphviz-compatible format;
183 // only useful for debugging.
184 void output_dot(const char *filename);
185 std::vector<std::string> get_labels_for_edge(const Node *from, const Node *to);
186 void output_dot_edge(FILE *fp,
187 const std::string &from_node_id,
188 const std::string &to_node_id,
189 const std::vector<std::string> &labels);
191 // Some of the graph algorithms assume that the nodes array is sorted
192 // topologically (inputs are always before outputs), but some operations
193 // (like graph rewriting) can change that. This function restores that order.
194 void sort_all_nodes_topologically();
196 // Do the actual topological sort. <nodes> must be a connected, acyclic subgraph;
197 // links that go to nodes not in the set will be ignored.
198 std::vector<Node *> topological_sort(const std::vector<Node *> &nodes);
200 // Utility function used by topological_sort() to do a depth-first search.
201 // The reason why we store nodes left to visit instead of a more conventional
202 // list of nodes to visit is that we want to be able to limit ourselves to
203 // a subgraph instead of all nodes. The set thus serves a dual purpose.
204 void topological_sort_visit_node(Node *node, std::set<Node *> *nodes_left_to_visit, std::vector<Node *> *sorted_list);
206 // Used during finalize().
207 void find_color_spaces_for_inputs();
208 void propagate_alpha();
209 void propagate_gamma_and_color_space();
210 Node *find_output_node();
212 bool node_needs_colorspace_fix(Node *node);
213 void fix_internal_color_spaces();
214 void fix_output_color_space();
216 bool node_needs_alpha_fix(Node *node);
217 void fix_internal_alpha(unsigned step);
218 void fix_output_alpha();
220 bool node_needs_gamma_fix(Node *node);
221 void fix_internal_gamma_by_asking_inputs(unsigned step);
222 void fix_internal_gamma_by_inserting_nodes(unsigned step);
223 void fix_output_gamma();
224 void add_dither_if_needed();
226 float aspect_nom, aspect_denom;
227 ImageFormat output_format;
228 OutputAlphaFormat output_alpha_format;
230 std::vector<Node *> nodes;
231 std::map<Effect *, Node *> node_map;
232 Effect *dither_effect;
234 std::vector<Input *> inputs; // Also contained in nodes.
237 std::vector<Phase *> phases;
239 unsigned num_dither_bits;
243 #endif // !defined(_EFFECT_CHAIN_H)