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