// Thread-safety: All functions except the constructor and destructor can be
// safely called from multiple threads at the same time, provided they have
// separate (but sharing) OpenGL contexts.
+//
+// Memory management (only relevant if you use multiple contexts): Some objects,
+// like FBOs, are not shareable across contexts, and can only be deleted from
+// the context they were created in. Thus, you will need to tell the
+// ResourcePool explicitly if you delete a context, or they will leak (and the
+// ResourcePool destructor will assert-fail). See clean_context().
-#include <GL/glew.h>
+#include <epoxy/gl.h>
#include <pthread.h>
#include <stddef.h>
#include <list>
// 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);
+ size_t fbo_freelist_max_length = 100); // Per context.
~ResourcePool();
// All remaining functions are intended for calls from EffectChain only.
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().
+ // Allocate an FBO with the the given texture(s) bound as framebuffer attachment(s),
+ // 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.
//
// 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,
+ // 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, GLint internal_format, GLsizei width, GLsizei height);
+ // shareable across contexts, so you must have the context that's supposed
+ // to own the FBO current when you create or release it.
+ GLuint create_fbo(GLuint texture0_num,
+ GLuint texture1_num = 0,
+ GLuint texture2_num = 0,
+ GLuint texture3_num = 0);
void release_fbo(GLuint fbo_num);
+ // Informs the ResourcePool that the current context is going away soon,
+ // and that any resources held for it in the freelist should be deleted.
+ //
+ // You do not need to do this for the last context; the regular destructor
+ // will take care of that. This means that if you only ever use one
+ // thread/context, you never need to call this function.
+ void clean_context();
+
private:
// Delete the given program and both its shaders.
void delete_program(GLuint program_num);
+ // Deletes all FBOs for the given context that belong to deleted textures.
+ void cleanup_unlinked_fbos(void *context);
+
+ // Remove FBOs off the end of the freelist for <context>, until it
+ // is no more than <max_length> elements long.
+ void shrink_fbo_freelist(void *context, size_t max_length);
+
// Protects all the other elements in the class.
pthread_mutex_t lock;
std::list<GLuint> texture_freelist;
size_t texture_freelist_bytes;
+ static const unsigned num_fbo_attachments = 4;
struct FBO {
- void *context;
- GLint internal_format;
- GLsizei width, height;
+ // GL_INVALID_INDEX means associated to a texture that has since been deleted.
+ // 0 means the output isn't bound.
+ GLuint texture_num[num_fbo_attachments];
};
- // 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;
+ // For each context, 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<std::pair<void *, 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;
+ // For each context, a list of all FBOs that are released but not freed
+ // (most recently freed first). Once this reaches <fbo_freelist_max_length>,
+ // the last element will be deleted.
+ std::map<void *, std::list<GLuint> > fbo_freelist;
// See the caveats at the constructor.
static size_t estimate_texture_size(const Texture2D &texture_format);