Explicitly bind fragment shader outputs in order.

[movit] / resource_pool.h

diff --git a/resource_pool.h b/resource_pool.h
index aad95c959ad235dc7cdc504f82e066b717322279..5cc2e829e8f836635b04980978372973d3618639 100644 (file)
--- a/resource_pool.h
+++ b/resource_pool.h
@@ -22,13 +22,14 @@
 // 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>
 #include <map>
 #include <string>
 #include <utility>
+#include <vector>
 
 namespace movit {
 
@@ -56,7 +57,14 @@ public:
        // compiled program from the cache if possible. Keeps ownership of the
        // program; you must call release_glsl_program() instead of deleting it
        // when you no longer want it.
-       GLuint compile_glsl_program(const std::string& vertex_shader, const std::string& fragment_shader);
+       //
+       // If <fragment_shader_outputs> contains more than one value, the given
+       // outputs will be bound to fragment shader output colors in the order
+       // they appear in the vector. Otherwise, output order is undefined and
+       // determined by the OpenGL driver.
+       GLuint compile_glsl_program(const std::string& vertex_shader,
+                                   const std::string& fragment_shader,
+                                   const std::vector<std::string>& frag_shader_outputs);
        void release_glsl_program(GLuint glsl_program_num);
 
        // Allocate a 2D texture of the given internal format and dimensions,
@@ -66,7 +74,7 @@ public:
        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,
+       // 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.
@@ -77,7 +85,10 @@ public:
        // in particular on NVidia cards. Also, keep in mind that FBOs are not
        // 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 texture_num);
+       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,
@@ -138,19 +149,26 @@ private:
        std::list<GLuint> texture_freelist;
        size_t texture_freelist_bytes;
 
+       static const unsigned num_fbo_attachments = 4;
        struct FBO {
-               GLuint texture_num;  // 0 means associated to a texture that has since been deleted.
+               GLuint fbo_num;
+               // 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];
        };
 
        // 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;
+       typedef std::map<std::pair<void *, GLuint>, FBO>::iterator FBOFormatIterator;
 
        // 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;
+       //
+       // We store iterators directly into <fbo_format> for efficiency.
+       std::map<void *, std::list<FBOFormatIterator> > fbo_freelist;
 
        // See the caveats at the constructor.
        static size_t estimate_texture_size(const Texture2D &texture_format);