X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=resource_pool.h;h=ae89d9f517e5c09a36bd0ea0eba99777990b0c56;hp=a6e4327b2e953ca5747f6b6dfac8d6e8811426f3;hb=88ee2edc41d536c7057424df185fc6b49f993896;hpb=edb0700c0a8ea225ce9add1cb4f70d42af6de381

diff --git a/resource_pool.h b/resource_pool.h
index a6e4327..ae89d9f 100644
--- a/resource_pool.h
+++ b/resource_pool.h
@@ -16,12 +16,13 @@
 // 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>
 
 class ResourcePool {
 public:
@@ -29,7 +30,15 @@ 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.
 	~ResourcePool();
 
 	// All remaining functions are intended for calls from EffectChain only.
@@ -41,6 +50,15 @@ 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.
+	//
+	// 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);
+
 private:
 	// Delete the given program and both its shaders.
 	void delete_program(GLuint program_num);
@@ -48,7 +66,7 @@ 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;
 		
 	// A mapping from vertex/fragment shader source strings to compiled program number.
 	std::map<std::pair<std::string, std::string>, GLuint> programs;
@@ -62,8 +80,30 @@ 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;
+
+	// See the caveats at the constructor.
+	static size_t estimate_texture_size(const Texture2D &texture_format);
 };
 
 #endif  // !defined(_MOVIT_RESOURCE_POOL_H)