Have separate FBOs per resolution and format.

[movit] / resource_pool.h

diff --git a/resource_pool.h b/resource_pool.h
index 14c75e22797386c09a0f796d7db53d936a600ea3..86d00592748efeaf3d94ab1c5666c0f54de296be 100644 (file)
--- a/resource_pool.h
+++ b/resource_pool.h
@@ -40,7 +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.
@@ -59,6 +60,19 @@ public:
        GLuint create_2d_texture(GLint internal_format, GLsizei width, GLsizei height);
        void release_2d_texture(GLuint texture_num);
 
+       // Allocate an FBO used for the given internal format and dimensions,
+       // or fetch a previous used if possible. 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
+       // resolution or pixel formats can have an adverse effect on performance,
+       // in particular on NVidia cards. Also, keep in mind that FBOs are not
+       // shareable across contexts.
+       GLuint create_fbo(void *context, GLint internal_format, GLsizei width, GLsizei height);
+       void release_fbo(GLuint fbo_num);
+
 private:
        // Delete the given program and both its shaders.
        void delete_program(GLuint program_num);
@@ -66,7 +80,7 @@ private:
        // 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;
@@ -102,6 +116,22 @@ private:
        std::list<GLuint> texture_freelist;
        size_t texture_freelist_bytes;
 
+       struct FBO {
+               void *context;
+               GLint internal_format;
+               GLsizei width, height;
+       };
+
+       // 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);
 };