// 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:
// 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.
// 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);
// 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;
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)