From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Sat, 22 Mar 2014 13:57:53 +0000 (+0100)
Subject: Merge branch 'master' into epoxy
X-Git-Tag: 1.1~12^2~5
X-Git-Url: https://git.sesse.net/?a=commitdiff_plain;h=ddf71f853e64c3912eed4ab98bfe7503826ce8e1;hp=-c;p=movit

Merge branch 'master' into epoxy

Conflicts:
	flat_input.cpp
---

ddf71f853e64c3912eed4ab98bfe7503826ce8e1
diff --combined effect_chain.cpp
index 82f1b29,ca6a777..4793845
--- a/effect_chain.cpp
+++ b/effect_chain.cpp
@@@ -1,6 -1,6 +1,6 @@@
  #define GL_GLEXT_PROTOTYPES 1
  
 -#include <GL/glew.h>
 +#include <epoxy/gl.h>
  #include <assert.h>
  #include <locale.h>
  #include <math.h>
@@@ -68,11 -68,6 +68,6 @@@ EffectChain::~EffectChain(
  	if (owns_resource_pool) {
  		delete resource_pool;
  	}
- 	for (map<void *, GLuint>::const_iterator fbo_it = fbos.begin();
- 	     fbo_it != fbos.end(); ++fbo_it) {
- 		glDeleteFramebuffers(1, &fbo_it->second);
- 		check_error();
- 	}
  }
  
  Input *EffectChain::add_input(Input *input)
@@@ -243,7 -238,7 +238,7 @@@ string replace_prefix(const string &tex
  
  void EffectChain::compile_glsl_program(Phase *phase)
  {
 -	string frag_shader = read_file("header.frag");
 +	string frag_shader = read_version_dependent_file("header", "frag");
  
  	// Create functions for all the texture inputs that we need.
  	for (unsigned i = 0; i < phase->inputs.size(); ++i) {
@@@ -254,7 -249,7 +249,7 @@@
  	
  		frag_shader += string("uniform sampler2D tex_") + effect_id + ";\n";
  		frag_shader += string("vec4 ") + effect_id + "(vec2 tc) {\n";
 -		frag_shader += "\treturn texture2D(tex_" + string(effect_id) + ", tc);\n";
 +		frag_shader += "\treturn tex2D(tex_" + string(effect_id) + ", tc);\n";
  		frag_shader += "}\n";
  		frag_shader += "\n";
  	}
@@@ -293,10 -288,9 +288,10 @@@
  		frag_shader += "\n";
  	}
  	frag_shader += string("#define INPUT ") + phase->effect_ids[phase->effects.back()] + "\n";
 -	frag_shader.append(read_file("footer.frag"));
 +	frag_shader.append(read_version_dependent_file("footer", "frag"));
  
 -	phase->glsl_program_num = resource_pool->compile_glsl_program(read_file("vs.vert"), frag_shader);
 +	string vert_shader = read_version_dependent_file("vs", "vert");
 +	phase->glsl_program_num = resource_pool->compile_glsl_program(vert_shader, frag_shader);
  
  	// Prepare the geometry for the fullscreen quad used in this phase.
  	// (We have separate VAOs per shader, since the bindings can in theory
@@@ -1460,47 -1454,37 +1455,37 @@@ void EffectChain::render_to_fbo(GLuint 
  	glDepthMask(GL_FALSE);
  	check_error();
  
- 	if (phases.size() > 1) {
- 		if (fbos.count(context) == 0) {
- 			glGenFramebuffers(1, &fbo);
- 			check_error();
- 			fbos.insert(make_pair(context, fbo));
- 		} else {
- 			fbo = fbos[context];
- 		}
- 		glBindFramebuffer(GL_FRAMEBUFFER, fbo);
- 		check_error();
- 	}
- 
  	set<Phase *> generated_mipmaps;
  
  	// We choose the simplest option of having one texture per output,
  	// since otherwise this turns into an (albeit simple) register allocation problem.
  	map<Phase *, GLuint> output_textures;
  
- 	for (unsigned phase = 0; phase < phases.size(); ++phase) {
+ 	for (unsigned phase_num = 0; phase_num < phases.size(); ++phase_num) {
+ 		Phase *phase = phases[phase_num];
+ 
  		// Find a texture for this phase.
- 		inform_input_sizes(phases[phase]);
- 		if (phase != phases.size() - 1) {
- 			find_output_size(phases[phase]);
+ 		inform_input_sizes(phase);
+ 		if (phase_num != phases.size() - 1) {
+ 			find_output_size(phase);
  
- 			GLuint tex_num = resource_pool->create_2d_texture(GL_RGBA16F_ARB, phases[phase]->output_width, phases[phase]->output_height);
- 			output_textures.insert(make_pair(phases[phase], tex_num));
+ 			GLuint tex_num = resource_pool->create_2d_texture(GL_RGBA16F, phase->output_width, phase->output_height);
+ 			output_textures.insert(make_pair(phase, tex_num));
  		}
  
- 		const GLuint glsl_program_num = phases[phase]->glsl_program_num;
+ 		const GLuint glsl_program_num = phase->glsl_program_num;
  		check_error();
  		glUseProgram(glsl_program_num);
  		check_error();
  
  		// Set up RTT inputs for this phase.
- 		for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
+ 		for (unsigned sampler = 0; sampler < phase->inputs.size(); ++sampler) {
  			glActiveTexture(GL_TEXTURE0 + sampler);
- 			Phase *input = phases[phase]->inputs[sampler];
+ 			Phase *input = phase->inputs[sampler];
  			input->output_node->bound_sampler_num = sampler;
  			glBindTexture(GL_TEXTURE_2D, output_textures[input]);
  			check_error();
- 			if (phases[phase]->input_needs_mipmaps) {
+ 			if (phase->input_needs_mipmaps) {
  				if (generated_mipmaps.count(input) == 0) {
  					glGenerateMipmap(GL_TEXTURE_2D);
  					check_error();
@@@ -1517,13 -1501,13 +1502,13 @@@
  			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  			check_error();
  
- 			string texture_name = string("tex_") + phases[phase]->effect_ids[input->output_node];
+ 			string texture_name = string("tex_") + phase->effect_ids[input->output_node];
  			glUniform1i(glGetUniformLocation(glsl_program_num, texture_name.c_str()), sampler);
  			check_error();
  		}
  
  		// And now the output.
- 		if (phase == phases.size() - 1) {
+ 		if (phase_num == phases.size() - 1) {
  			// Last phase goes to the output the user specified.
  			glBindFramebuffer(GL_FRAMEBUFFER, dest_fbo);
  			check_error();
@@@ -1535,24 -1519,17 +1520,17 @@@
  				CHECK(dither_effect->set_int("output_height", height));
  			}
  		} else {
- 			glFramebufferTexture2D(
- 				GL_FRAMEBUFFER,
- 			        GL_COLOR_ATTACHMENT0,
- 				GL_TEXTURE_2D,
- 				output_textures[phases[phase]],
- 				0);
- 			check_error();
- 			GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
- 			assert(status == GL_FRAMEBUFFER_COMPLETE);
- 			glViewport(0, 0, phases[phase]->output_width, phases[phase]->output_height);
+ 			fbo = resource_pool->create_fbo(context, output_textures[phase]);
+ 			glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+ 			glViewport(0, 0, phase->output_width, phase->output_height);
  		}
  
  		// Give the required parameters to all the effects.
- 		unsigned sampler_num = phases[phase]->inputs.size();
- 		for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
- 			Node *node = phases[phase]->effects[i];
+ 		unsigned sampler_num = phase->inputs.size();
+ 		for (unsigned i = 0; i < phase->effects.size(); ++i) {
+ 			Node *node = phase->effects[i];
  			unsigned old_sampler_num = sampler_num;
- 			node->effect->set_gl_state(glsl_program_num, phases[phase]->effect_ids[node], &sampler_num);
+ 			node->effect->set_gl_state(glsl_program_num, phase->effect_ids[node], &sampler_num);
  			check_error();
  
  			if (node->effect->is_single_texture()) {
@@@ -1563,15 -1540,18 +1541,18 @@@
  			}
  		}
  
- 		glBindVertexArray(phases[phase]->vao);
+ 		glBindVertexArray(phase->vao);
  		check_error();
  		glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
  		check_error();
  
- 		for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
- 			Node *node = phases[phase]->effects[i];
+ 		for (unsigned i = 0; i < phase->effects.size(); ++i) {
+ 			Node *node = phase->effects[i];
  			node->effect->clear_gl_state();
  		}
+ 		if (phase_num != phases.size() - 1) {
+ 			resource_pool->release_fbo(fbo);
+ 		}
  	}
  
  	for (map<Phase *, GLuint>::const_iterator texture_it = output_textures.begin();
diff --combined effect_chain.h
index 1ecee63,6ce2332..a1bf3cb
--- a/effect_chain.h
+++ b/effect_chain.h
@@@ -17,7 -17,7 +17,7 @@@
  // the EffectChain holds textures and other OpenGL objects that are tied to the
  // context.
  
 -#include <GL/glew.h>
 +#include <epoxy/gl.h>
  #include <stdio.h>
  #include <map>
  #include <set>
@@@ -287,7 -287,6 +287,6 @@@ private
  	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;
  
diff --combined effect_chain_test.cpp
index 2552b6f,673e9cc..50d004d
--- a/effect_chain_test.cpp
+++ b/effect_chain_test.cpp
@@@ -2,7 -2,7 +2,7 @@@
  //
  // Note that this also contains the tests for some of the simpler effects.
  
 -#include <GL/glew.h>
 +#include <epoxy/gl.h>
  #include <assert.h>
  
  #include "effect.h"
@@@ -152,23 -152,19 +152,23 @@@ TEST(EffectChainTest, RewritingWorksAnd
  
  TEST(EffectChainTest, RewritingWorksAndTexturesAreAskedForsRGB) {
  	unsigned char data[] = {
 -		0, 64,
 -		128, 255,
 +		  0,   0,   0, 255,
 +		 64,  64,  64, 255,
 +		128, 128, 128, 255,
 +		255, 255, 255, 255,
  	};
 -	float expected_data[4] = {
 -		1.0f, 0.9771f,
 -		0.8983f, 0.0f,
 +	float expected_data[] = {
 +		1.0000f, 1.0000f, 1.0000f, 1.0000f,
 +		0.9771f, 0.9771f, 0.9771f, 1.0000f,
 +		0.8983f, 0.8983f, 0.8983f, 1.0000f,
 +		0.0000f, 0.0000f, 0.0000f, 1.0000f
  	};
 -	float out_data[4];
 -	EffectChainTester tester(NULL, 2, 2);
 -	tester.add_input(data, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_sRGB);
 +	float out_data[4 * 4];
 +	EffectChainTester tester(NULL, 1, 4);
 +	tester.add_input(data, FORMAT_RGBA_POSTMULTIPLIED_ALPHA, COLORSPACE_sRGB, GAMMA_sRGB);
  	RewritingEffect<InvertEffect> *effect = new RewritingEffect<InvertEffect>();
  	tester.get_chain()->add_effect(effect);
 -	tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_sRGB);
 +	tester.run(out_data, GL_RGBA, COLORSPACE_sRGB, GAMMA_sRGB);
  
  	Node *node = effect->replaced_node;
  	ASSERT_EQ(1, node->incoming_links.size());
@@@ -176,7 -172,7 +176,7 @@@
  	EXPECT_EQ("FlatInput", node->incoming_links[0]->effect->effect_type_id());
  	EXPECT_EQ("GammaCompressionEffect", node->outgoing_links[0]->effect->effect_type_id());
  
 -	expect_equal(expected_data, out_data, 2, 2);
 +	expect_equal(expected_data, out_data, 4, 4);
  }
  
  TEST(EffectChainTest, RewritingWorksAndColorspaceConversionsAreInserted) {
@@@ -227,7 -223,7 +227,7 @@@ private
  	GammaCurve overridden_gamma_curve;
  };
  
- TEST(EffectChainTester, HandlesInputChangingColorspace) {
+ TEST(EffectChainTest, HandlesInputChangingColorspace) {
  	const int size = 4;
  
  	float data[size] = {
diff --combined resource_pool.cpp
index 9beae1b,a83add2..10eeb9b
--- a/resource_pool.cpp
+++ b/resource_pool.cpp
@@@ -6,8 -6,8 +6,8 @@@
  #include <map>
  #include <string>
  #include <utility>
 +#include <epoxy/gl.h>
  
 -#include "glew.h"
  #include "init.h"
  #include "resource_pool.h"
  #include "util.h"
@@@ -17,10 -17,13 +17,13 @@@ using namespace std
  namespace movit {
  
  ResourcePool::ResourcePool(size_t program_freelist_max_length,
-                            size_t texture_freelist_max_bytes)
+                            size_t texture_freelist_max_bytes,
+                            size_t fbo_freelist_max_length)
  	: program_freelist_max_length(program_freelist_max_length),
  	  texture_freelist_max_bytes(texture_freelist_max_bytes),
- 	  texture_freelist_bytes(0) {
+ 	  fbo_freelist_max_length(fbo_freelist_max_length),
+ 	  texture_freelist_bytes(0)
+ {
  	pthread_mutex_init(&lock, NULL);
  }
  
@@@ -48,6 -51,17 +51,17 @@@ ResourcePool::~ResourcePool(
  	}
  	assert(texture_formats.empty());
  	assert(texture_freelist_bytes == 0);
+ 
+ 	for (list<GLuint>::const_iterator freelist_it = fbo_freelist.begin();
+ 	     freelist_it != fbo_freelist.end();
+ 	     ++freelist_it) {
+ 		GLuint free_fbo_num = *freelist_it;
+ 		assert(fbo_formats.count(free_fbo_num) != 0);
+ 		fbo_formats.erase(free_fbo_num);
+ 		glDeleteFramebuffers(1, &free_fbo_num);
+ 		check_error();
+ 	}
+ 	assert(fbo_formats.empty());
  }
  
  void ResourcePool::delete_program(GLuint glsl_program_num)
@@@ -186,18 -200,10 +200,18 @@@ GLuint ResourcePool::create_2d_texture(
  	case GL_SRGB8_ALPHA8:
  		format = GL_RGBA;
  		break;
 +	case GL_RGB32F:
 +	case GL_RGB16F:
 +	case GL_RGB8:
 +		format = GL_RGB;
 +		break;
  	case GL_RG32F:
  	case GL_RG16F:
 +	case GL_RG8:
  		format = GL_RG;
  		break;
 +	case GL_R32F:
 +	case GL_R16F:
  	case GL_R8:
  		format = GL_RED;
  		break;
@@@ -206,38 -212,12 +220,38 @@@
  		assert(false);
  	}
  
 +	// Same with type; GLES is stricter than desktop OpenGL here.
 +	GLenum type;
 +	switch (internal_format) {
 +	case GL_RGBA32F_ARB:
 +	case GL_RGBA16F_ARB:
 +	case GL_RGB32F:
 +	case GL_RGB16F:
 +	case GL_RG32F:
 +	case GL_RG16F:
 +	case GL_R32F:
 +	case GL_R16F:
 +		type = GL_FLOAT;
 +		break;
 +	case GL_SRGB8_ALPHA8:
 +	case GL_RGBA8:
 +	case GL_RGB8:
 +	case GL_RG8:
 +	case GL_R8:
 +		type = GL_UNSIGNED_BYTE;
 +		break;
 +	default:
 +		// TODO: Add more here as needed.
 +		assert(false);
 +	}
 +
 +
  	GLuint texture_num;
  	glGenTextures(1, &texture_num);
  	check_error();
  	glBindTexture(GL_TEXTURE_2D, texture_num);
  	check_error();
 -	glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, GL_UNSIGNED_BYTE, NULL);
 +	glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, type, NULL);
  	check_error();
  	glBindTexture(GL_TEXTURE_2D, 0);
  	check_error();
@@@ -268,6 -248,83 +282,83 @@@ void ResourcePool::release_2d_texture(G
  		texture_formats.erase(free_texture_num);
  		glDeleteTextures(1, &free_texture_num);
  		check_error();
+ 
+ 		// Delete any FBO related to this texture.
+ 		for (list<GLuint>::iterator fbo_freelist_it = fbo_freelist.begin();
+ 		     fbo_freelist_it != fbo_freelist.end(); ) {
+ 			GLuint fbo_num = *fbo_freelist_it;
+ 			map<GLuint, FBO>::const_iterator format_it = fbo_formats.find(fbo_num);
+ 			assert(format_it != fbo_formats.end());
+ 			if (format_it->second.texture_num == free_texture_num) {
+ 				glDeleteFramebuffers(1, &fbo_num);
+ 				fbo_freelist.erase(fbo_freelist_it++);
+ 			} else {
+ 				++fbo_freelist_it;
+ 			}
+ 		}
+ 	}
+ 	pthread_mutex_unlock(&lock);
+ }
+ 
+ GLuint ResourcePool::create_fbo(void *context, GLuint texture_num)
+ {
+ 	pthread_mutex_lock(&lock);
+ 	// See if there's an FBO on the freelist we can use.
+ 	for (list<GLuint>::iterator freelist_it = fbo_freelist.begin();
+ 	     freelist_it != fbo_freelist.end();
+ 	     ++freelist_it) {
+ 		GLuint fbo_num = *freelist_it;
+ 		map<GLuint, FBO>::const_iterator format_it = fbo_formats.find(fbo_num);
+ 		assert(format_it != fbo_formats.end());
+ 		if (format_it->second.context == context &&
+ 		    format_it->second.texture_num == texture_num) {
+ 			fbo_freelist.erase(freelist_it);
+ 			pthread_mutex_unlock(&lock);
+ 			return fbo_num;
+ 		}
+ 	}
+ 
+ 	// Create a new one.
+ 	GLuint fbo_num;
+ 	glGenFramebuffers(1, &fbo_num);
+ 	check_error();
+ 	glBindFramebuffer(GL_FRAMEBUFFER, fbo_num);
+ 	check_error();
+ 	glFramebufferTexture2D(
+ 		GL_FRAMEBUFFER,
+ 		GL_COLOR_ATTACHMENT0,
+ 		GL_TEXTURE_2D,
+ 		texture_num,
+ 		0);
+ 	check_error();
+ 	GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+ 	assert(status == GL_FRAMEBUFFER_COMPLETE);
+ 	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+ 	check_error();
+ 
+ 	FBO fbo_format;
+ 	fbo_format.context = context;
+ 	fbo_format.texture_num = texture_num;
+ 	assert(fbo_formats.count(fbo_num) == 0);
+ 	fbo_formats.insert(make_pair(fbo_num, fbo_format));
+ 
+ 	pthread_mutex_unlock(&lock);
+ 	return fbo_num;
+ }
+ 
+ void ResourcePool::release_fbo(GLuint fbo_num)
+ {
+ 	pthread_mutex_lock(&lock);
+ 	fbo_freelist.push_front(fbo_num);
+ 	assert(fbo_formats.count(fbo_num) != 0);
+ 
+ 	while (fbo_freelist.size() > fbo_freelist_max_length) {
+ 		GLuint free_fbo_num = fbo_freelist.front();
+ 		fbo_freelist.pop_front();
+ 		assert(fbo_formats.count(free_fbo_num) != 0);
+ 		fbo_formats.erase(free_fbo_num);
+ 		glDeleteFramebuffers(1, &free_fbo_num);
+ 		check_error();
  	}
  	pthread_mutex_unlock(&lock);
  }
@@@ -283,32 -340,16 +374,32 @@@ size_t ResourcePool::estimate_texture_s
  	case GL_RGBA16F_ARB:
  		bytes_per_pixel = 8;
  		break;
 +	case GL_RGB32F_ARB:
 +		bytes_per_pixel = 12;
 +		break;
 +	case GL_RGB16F_ARB:
 +		bytes_per_pixel = 6;
 +		break;
  	case GL_RGBA8:
  	case GL_SRGB8_ALPHA8:
  		bytes_per_pixel = 4;
  		break;
 +	case GL_RGB8:
 +	case GL_SRGB8:
 +		bytes_per_pixel = 3;
 +		break;
  	case GL_RG32F:
  		bytes_per_pixel = 8;
  		break;
  	case GL_RG16F:
  		bytes_per_pixel = 4;
  		break;
 +	case GL_R32F:
 +		bytes_per_pixel = 4;
 +		break;
 +	case GL_R16F:
 +		bytes_per_pixel = 2;
 +		break;
  	case GL_R8:
  		bytes_per_pixel = 1;
  		break;
diff --combined resource_pool.h
index d8d8cec,4ae4110..7029fbf
--- a/resource_pool.h
+++ b/resource_pool.h
@@@ -16,7 -16,7 +16,7 @@@
  // safely called from multiple threads at the same time, provided they have
  // separate (but sharing) OpenGL contexts.
  
 -#include <GL/glew.h>
 +#include <epoxy/gl.h>
  #include <pthread.h>
  #include <stddef.h>
  #include <list>
@@@ -40,7 -40,8 +40,8 @@@ public
  	// This means you should be prepared for actual memory usage of the freelist being
  	// twice this estimate or more.
  	ResourcePool(size_t program_freelist_max_length = 100,
- 	             size_t texture_freelist_max_bytes = 100 << 20);  // 100 MB.
+ 	             size_t texture_freelist_max_bytes = 100 << 20,  // 100 MB.
+ 	             size_t fbo_freelist_max_length = 100);
  	~ResourcePool();
  
  	// All remaining functions are intended for calls from EffectChain only.
@@@ -56,11 -57,23 +57,23 @@@
  	// or fetch a previous used if possible. Unbinds GL_TEXTURE_2D afterwards.
  	// Keeps ownership of the texture; you must call release_2d_texture() instead
  	// of deleting it when you no longer want it.
- 	//
- 	// Note: Currently we do not actually have a freelist, but this will change soon.
  	GLuint create_2d_texture(GLint internal_format, GLsizei width, GLsizei height);
  	void release_2d_texture(GLuint texture_num);
  
+ 	// Allocate an FBO with the the given texture bound as a framebuffer attachment,
+ 	// or fetch a previous used if possible. Unbinds GL_FRAMEBUFFER afterwards.
+ 	// Keeps ownership of the FBO; you must call release_fbo() of deleting
+ 	// it when you no longer want it. You can get an appropriate context
+ 	// pointer from get_gl_context_identifier().
+ 	//
+ 	// NOTE: In principle, the FBO doesn't have a resolution or pixel format;
+ 	// you can bind almost whatever texture you want to it. However, changing
+ 	// textures can have an adverse effect on performance due to validation,
+ 	// in particular on NVidia cards. Also, keep in mind that FBOs are not
+ 	// shareable across contexts.
+ 	GLuint create_fbo(void *context, GLuint texture_num);
+ 	void release_fbo(GLuint fbo_num);
+ 
  private:
  	// Delete the given program and both its shaders.
  	void delete_program(GLuint program_num);
@@@ -68,7 -81,7 +81,7 @@@
  	// Protects all the other elements in the class.
  	pthread_mutex_t lock;
  
- 	size_t program_freelist_max_length, texture_freelist_max_bytes;
+ 	size_t program_freelist_max_length, texture_freelist_max_bytes, fbo_freelist_max_length;
  		
  	// A mapping from vertex/fragment shader source strings to compiled program number.
  	std::map<std::pair<std::string, std::string>, GLuint> programs;
@@@ -104,6 -117,21 +117,21 @@@
  	std::list<GLuint> texture_freelist;
  	size_t texture_freelist_bytes;
  
+ 	struct FBO {
+ 		void *context;
+ 		GLuint texture_num;
+ 	};
+ 
+ 	// A mapping from FBO number to format details. This is filled if the
+ 	// FBO is given out to a client or on the freelist, but not if it is
+ 	// deleted from the freelist.
+ 	std::map<GLuint, FBO> fbo_formats;
+ 
+ 	// A list of all FBOs that are release but not freed (most recently freed
+ 	// first). Once this reaches <fbo_freelist_max_length>, the last element
+ 	// will be deleted.
+ 	std::list<GLuint> fbo_freelist;
+ 
  	// See the caveats at the constructor.
  	static size_t estimate_texture_size(const Texture2D &texture_format);
  };