-#ifndef _EFFECT_CHAIN_H
-#define _EFFECT_CHAIN_H 1
+#ifndef _MOVIT_EFFECT_CHAIN_H
+#define _MOVIT_EFFECT_CHAIN_H 1
+// An EffectChain is the largest basic entity in Movit; it contains everything
+// needed to connects a series of effects, from inputs to outputs, and render
+// them. Generally you set up your effect chain once and then call its render
+// functions once per frame; setting one up can be relatively expensive,
+// but rendering is fast.
+//
+// Threading considerations: EffectChain is “thread-compatible”; you can use
+// different EffectChains in multiple threads at the same time (assuming the
+// threads do not use the same OpenGL context, but this is a good idea anyway),
+// but you may not use one EffectChain from multiple threads simultaneously.
+// You _are_ allowed to use one EffectChain from multiple threads as long as
+// you only use it from one at a time (possibly by doing your own locking),
+// but if so, the threads' contexts need to be set up to share resources, since
+// the EffectChain holds textures and other OpenGL objects that are tied to the
+// context.
+
+#include <GL/glew.h>
+#include <stdio.h>
+#include <map>
#include <set>
+#include <string>
#include <vector>
-#include "effect.h"
-#include "effect_id.h"
+#include "image_format.h"
+
+namespace movit {
-enum PixelFormat { FORMAT_RGB, FORMAT_RGBA, FORMAT_BGR, FORMAT_BGRA };
+class Effect;
+class Input;
+struct Phase;
+class ResourcePool;
-enum ColorSpace {
- COLORSPACE_sRGB = 0,
- COLORSPACE_REC_709 = 0, // Same as sRGB.
- COLORSPACE_REC_601_525 = 1,
- COLORSPACE_REC_601_625 = 2,
+// For internal use within Node.
+enum AlphaType {
+ ALPHA_INVALID = -1,
+ ALPHA_BLANK,
+ ALPHA_PREMULTIPLIED,
+ ALPHA_POSTMULTIPLIED,
};
-enum GammaCurve {
- GAMMA_LINEAR = 0,
- GAMMA_sRGB = 1,
- GAMMA_REC_601 = 2,
- GAMMA_REC_709 = 2, // Same as Rec. 601.
+// 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_FORMAT_PREMULTIPLIED,
+ OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED,
};
-struct ImageFormat {
- PixelFormat pixel_format;
- ColorSpace color_space;
- GammaCurve gamma_curve;
+// A node in the graph; basically an effect and some associated information.
+class Node {
+public:
+ Effect *effect;
+ bool disabled;
+
+ // Edges in the graph (forward and backward).
+ std::vector<Node *> outgoing_links;
+ std::vector<Node *> incoming_links;
+
+private:
+ // Logical size of the output of this effect, ie. the resolution
+ // you would get if you sampled it as a texture. If it is undefined
+ // (since the inputs differ in resolution), it will be 0x0.
+ // If both this and output_texture_{width,height} are set,
+ // they will be equal.
+ unsigned output_width, output_height;
+
+ // If the effect has is_single_texture(), or if the output went to RTT
+ // and that texture has been bound to a sampler, the sampler number
+ // will be stored here.
+ //
+ // TODO: Can an RTT texture be used as inputs to multiple effects
+ // within the same phase? If so, we have a problem with modifying
+ // sampler state here.
+ int bound_sampler_num;
+
+ // Used during the building of the effect chain.
+ 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 {
+ Node *output_node;
+
+ GLuint glsl_program_num; // Owned by the resource_pool.
+ bool input_needs_mipmaps;
+
+ // Inputs are only inputs from other phases (ie., those that come from RTT);
+ // input textures are counted as part of <effects>.
+ std::vector<Phase *> inputs;
+ std::vector<Node *> effects; // In order.
+ unsigned output_width, output_height, virtual_output_width, virtual_output_height;
+
+ // Identifier used to create unique variables in GLSL.
+ // Unique per-phase to increase cacheability of compiled shaders.
+ std::map<Node *, std::string> effect_ids;
+
+ // The geometry needed to draw this quad, bound to the vertex array
+ // object. (Seemingly it's actually a win not to upload geometry every
+ // frame, even for something as small as a quad, due to fewer state
+ // changes.)
+ GLuint vao;
+ GLuint position_vbo, texcoord_vbo;
};
class EffectChain {
public:
- EffectChain(unsigned width, unsigned height);
+ // Aspect: e.g. 16.0f, 9.0f for 16:9.
+ // resource_pool is a pointer to a ResourcePool with which to share shaders
+ // and other resources (see resource_pool.h). If NULL (the default),
+ // will create its own that is not shared with anything else. Does not take
+ // ownership of the passed-in ResourcePool, but will naturally take ownership
+ // of its own internal one if created.
+ EffectChain(float aspect_nom, float aspect_denom, ResourcePool *resource_pool = NULL);
+ ~EffectChain();
// User API:
// input, effects, output, finalize need to come in that specific order.
- void add_input(const ImageFormat &format);
+ // EffectChain takes ownership of the given input.
+ // input is returned back for convenience.
+ Input *add_input(Input *input);
- // The returned pointer is owned by EffectChain.
- Effect *add_effect(EffectId effect) {
+ // EffectChain takes ownership of the given effect.
+ // effect is returned back for convenience.
+ Effect *add_effect(Effect *effect) {
return add_effect(effect, last_added_effect());
}
- Effect *add_effect(EffectId effect, Effect *input) {
+ Effect *add_effect(Effect *effect, Effect *input) {
std::vector<Effect *> inputs;
inputs.push_back(input);
return add_effect(effect, inputs);
}
- Effect *add_effect(EffectId effect, Effect *input1, Effect *input2) {
+ Effect *add_effect(Effect *effect, Effect *input1, Effect *input2) {
std::vector<Effect *> inputs;
inputs.push_back(input1);
inputs.push_back(input2);
return add_effect(effect, inputs);
}
- Effect *add_effect(EffectId effect, const std::vector<Effect *> &inputs);
+ Effect *add_effect(Effect *effect, Effect *input1, Effect *input2, Effect *input3) {
+ std::vector<Effect *> inputs;
+ inputs.push_back(input1);
+ inputs.push_back(input2);
+ inputs.push_back(input3);
+ return add_effect(effect, inputs);
+ }
+ Effect *add_effect(Effect *effect, const std::vector<Effect *> &inputs);
- // Similar to add_effect, but:
- //
- // * Does not insert any normalizing effects.
- // * Does not ask the effect to insert itself, so it won't work
- // with meta-effects.
- //
- // We should really separate out these two “sides” of Effect in the
- // type system soon.
- void add_effect_raw(Effect *effect, const std::vector<Effect *> &inputs);
+ 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 add_output(const ImageFormat &format);
void finalize();
+
//void render(unsigned char *src, unsigned char *dst);
- void render_to_screen(unsigned char *src);
+ 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 (effects.empty()) {
+ if (nodes.empty()) {
return NULL;
} else {
- return effects.back();
+ return nodes.back()->effect;
}
}
+ // API for manipulating the graph directly. Intended to be used from
+ // effects and by EffectChain itself.
+ //
+ // Note that for nodes with multiple inputs, the order of calls to
+ // connect_nodes() will matter.
+ Node *add_node(Effect *effect);
+ void connect_nodes(Node *sender, Node *receiver);
+ void replace_receiver(Node *old_receiver, Node *new_receiver);
+ void replace_sender(Node *new_sender, Node *receiver);
+ void insert_node_between(Node *sender, Node *middle, Node *receiver);
+ Node *find_node_for_effect(Effect *effect) { return node_map[effect]; }
+
+ // Get the OpenGL sampler (GL_TEXTURE0, GL_TEXTURE1, etc.) for the
+ // input of the given node, so that one can modify the sampler state
+ // directly. Only valid to call during set_gl_state().
+ //
+ // Also, for this to be allowed, <node>'s effect must have
+ // needs_texture_bounce() set, so that it samples directly from a
+ // single-sampler input, or from an RTT texture.
+ GLenum get_input_sampler(Node *node, unsigned input_num) const;
+
+ // Get the current resource pool assigned to this EffectChain.
+ // Primarily to let effects allocate textures as needed.
+ // Any resources you get from the pool must be returned to the pool
+ // no later than in the Effect's destructor.
+ ResourcePool *get_resource_pool() { return resource_pool; }
+
private:
- struct Phase {
- GLint glsl_program_num;
- bool input_needs_mipmaps;
- std::vector<Effect *> inputs;
- std::vector<Effect *> effects; // In order.
- };
+ // 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.
+ void inform_input_sizes(Phase *phase);
- Effect *normalize_to_linear_gamma(Effect *input);
- Effect *normalize_to_srgb(Effect *input);
+ // Determine the preferred output size of a given phase.
+ // Requires that all input phases (if any) already have output sizes set.
+ void find_output_size(Phase *phase);
- void draw_vertex(float x, float y, const std::vector<Effect *> &inputs);
+ // Find all inputs eventually feeding into this effect that have
+ // output gamma different from GAMMA_LINEAR.
+ void find_all_nonlinear_inputs(Node *effect, std::vector<Node *> *nonlinear_inputs);
- // Create a GLSL program computing the given effects in order.
- Phase compile_glsl_program(const std::vector<Effect *> &inputs, const std::vector<Effect *> &effects);
+ // Create a GLSL program computing the effects for this phase in order.
+ void compile_glsl_program(Phase *phase);
// Create all GLSL programs needed to compute the given effect, and all outputs
- // that depends on it (whenever possible).
- void construct_glsl_programs(Effect *start, std::set<Effect *> *completed_effects);
+ // that depend on it (whenever possible). Returns the phase that has <output>
+ // as the last effect. Also pushes all phases in order onto <phases>.
+ Phase *construct_phase(Node *output, std::map<Node *, Phase *> *completed_effects);
+
+ // 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_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);
- unsigned width, height;
- ImageFormat input_format, output_format;
- std::vector<Effect *> effects, unexpanded_effects;
- std::map<Effect *, std::string> effect_ids;
- std::map<Effect *, GLuint> effect_output_textures;
- std::map<Effect *, std::vector<Effect *> > outgoing_links;
- std::map<Effect *, std::vector<Effect *> > incoming_links;
+ // Used during finalize().
+ void find_color_spaces_for_inputs();
+ void propagate_alpha();
+ void propagate_gamma_and_color_space();
+ Node *find_output_node();
- GLuint source_image_num;
- bool use_srgb_texture_format;
+ bool node_needs_colorspace_fix(Node *node);
+ void fix_internal_color_spaces();
+ void fix_output_color_space();
- GLuint fbo;
- std::vector<Phase> phases;
+ bool node_needs_alpha_fix(Node *node);
+ void fix_internal_alpha(unsigned step);
+ void fix_output_alpha();
- GLenum format, bytes_per_pixel;
+ 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::map<void *, GLuint> fbos; // One for each OpenGL context.
+ std::vector<Input *> inputs; // Also contained in nodes.
+ std::vector<Phase *> phases;
+
+ unsigned num_dither_bits;
bool finalized;
- // Used during the building of the effect chain.
- std::map<Effect *, ColorSpace> output_color_space;
- std::map<Effect *, GammaCurve> output_gamma_curve;
+ ResourcePool *resource_pool;
+ bool owns_resource_pool;
};
+} // namespace movit
-#endif // !defined(_EFFECT_CHAIN_H)
+#endif // !defined(_MOVIT_EFFECT_CHAIN_H)
projects / movit / blobdiff