X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=resource_pool.h;h=4ae4110851387cd7dcfe21eb67f3f3f0e71cd695;hp=a6e4327b2e953ca5747f6b6dfac8d6e8811426f3;hb=0cdd6e9e30a807056699ed9b3fa023a23ce83af9;hpb=edb0700c0a8ea225ce9add1cb4f70d42af6de381

diff --git a/resource_pool.h b/resource_pool.h
index a6e4327..4ae4110 100644
--- a/resource_pool.h
+++ b/resource_pool.h
@@ -16,12 +16,15 @@
 // safely called from multiple threads at the same time, provided they have
 // separate (but sharing) OpenGL contexts.
 
+#include <GL/glew.h>
+#include <pthread.h>
+#include <stddef.h>
 #include <list>
 #include <map>
 #include <string>
 #include <utility>
-#include <GL/glew.h>
-#include <pthread.h>
+
+namespace movit {
 
 class ResourcePool {
 public:
@@ -29,7 +32,16 @@ public:
 	// around after they are no longer in use (in case another EffectChain
 	// wants that exact program later). Shaders are expensive to compile and do not
 	// need a lot of resources to keep around, so this should be a reasonable number.
-	ResourcePool(size_t program_freelist_max_length = 100);
+	//
+	// texture_freelist_max_bytes is how many bytes of unused textures to keep around
+	// after they are no longer in use (in case a new texture of the same dimensions
+	// and format is needed). Note that the size estimate is very coarse; it does not
+	// take into account padding, metadata, and most importantly mipmapping.
+	// 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 fbo_freelist_max_length = 100);
 	~ResourcePool();
 
 	// All remaining functions are intended for calls from EffectChain only.
@@ -41,6 +53,27 @@ public:
 	GLuint compile_glsl_program(const std::string& vertex_shader, const std::string& fragment_shader);
 	void release_glsl_program(GLuint glsl_program_num);
 
+	// Allocate a 2D texture of the given internal format and dimensions,
+	// 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.
+	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);
@@ -48,7 +81,7 @@ private:
 	// Protects all the other elements in the class.
 	pthread_mutex_t lock;
 
-	size_t program_freelist_max_length;
+	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;
@@ -62,8 +95,47 @@ private:
 	std::map<GLuint, std::pair<GLuint, GLuint> > program_shaders;
 
 	// A list of programs that are no longer in use, most recently freed first.
-	// Once this reaches <program_freelist_max_length>, 
+	// Once this reaches <program_freelist_max_length>, the last element
+	// will be deleted.
 	std::list<GLuint> program_freelist;
+
+	struct Texture2D {
+		GLint internal_format;
+		GLsizei width, height;
+	};
+
+	// A mapping from texture number to format details. This is filled if the
+	// texture is given out to a client or on the freelist, but not if it is
+	// deleted from the freelist.
+	std::map<GLuint, Texture2D> texture_formats;
+
+	// A list of all textures that are release but not freed (most recently freed
+	// first), and an estimate of their current memory usage. Once
+	// <texture_freelist_bytes> goes above <texture_freelist_max_bytes>,
+	// elements are deleted off the end of the list until we are under the limit
+	// again.
+	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);
 };
 
+}  // namespace movit
+
 #endif  // !defined(_MOVIT_RESOURCE_POOL_H)