-#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 <epoxy/gl.h>
+#include <stdio.h>
+#include <map>
#include <set>
+#include <string>
#include <vector>
-#include "effect.h"
#include "image_format.h"
-#include "input.h"
-class EffectChain;
+namespace movit {
+
+class Effect;
+class Input;
struct Phase;
+class ResourcePool;
// For internal use within Node.
enum AlphaType {
// 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_POSTMULTIPLIED_ALPHA,
+ OUTPUT_ALPHA_FORMAT_PREMULTIPLIED,
+ OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED,
};
// A node in the graph; basically an effect and some associated information.
std::vector<Node *> incoming_links;
private:
- // Identifier used to create unique variables in GLSL.
- std::string effect_id;
-
// 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.
// they will be equal.
unsigned output_width, output_height;
- // If output goes to RTT (otherwise, none of these are set).
- // The Phase pointer is a but ugly; we should probably fix so
- // that Phase takes other phases as inputs, instead of Node.
- GLuint output_texture;
- unsigned output_texture_width, output_texture_height;
+ // If output goes to RTT, which phase it is in (otherwise unset).
+ // This is a bit ugly; we should probably fix so that Phase takes other
+ // phases as inputs, instead of Node.
Phase *phase;
// Used during the building of the effect chain.
// A rendering phase; a single GLSL program rendering a single quad.
struct Phase {
- GLint glsl_program_num, vertex_shader, fragment_shader;
+ 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);
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;
};
class EffectChain {
public:
- EffectChain(float aspect_nom, float aspect_denom); // E.g., 16.0f, 9.0f for 16:9.
+ // 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:
void replace_sender(Node *new_sender, Node *receiver);
void insert_node_between(Node *sender, Node *middle, Node *receiver);
+ // 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:
// Make sure the output rectangle is at least large enough to hold
// the given input rectangle in both dimensions, and is of the
Effect *dither_effect;
std::vector<Input *> inputs; // Also contained in nodes.
-
- GLuint fbo;
std::vector<Phase *> phases;
unsigned num_dither_bits;
bool finalized;
+
+ ResourcePool *resource_pool;
+ bool owns_resource_pool;
};
-#endif // !defined(_EFFECT_CHAIN_H)
+} // namespace movit
+
+#endif // !defined(_MOVIT_EFFECT_CHAIN_H)