X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=effect_chain.h;h=1078027a7bfc3b859531ddd6932ff79c96cc1795;hp=f41e7e4a5e72966a9dd0a56255aca32cf6a3449b;hb=edb0700c0a8ea225ce9add1cb4f70d42af6de381;hpb=ac4fc36aa70ffefb6b9632dc0abea5cbbce5387b

diff --git a/effect_chain.h b/effect_chain.h
index f41e7e4..1078027 100644
--- a/effect_chain.h
+++ b/effect_chain.h
@@ -1,6 +1,22 @@
 #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>
@@ -13,6 +29,7 @@
 class Effect;
 class Input;
 struct Phase;
+class ResourcePool;
 
 // For internal use within Node.
 enum AlphaType {
@@ -67,7 +84,7 @@ private:
 
 // 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);
@@ -80,7 +97,13 @@ struct Phase {
 
 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:
@@ -229,12 +252,13 @@ private:
 	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(_MOVIT_EFFECT_CHAIN_H)