Keep FBOs around in EffectChain again.

Seemingly creating and deleting them is crazy expensive on NVidia
(~3 ms for a create/delete pair), so 6dea8d2 caused a performance
regression at high frame rates. Now we instead keep one around per
context (they cannot be shared), which brings us basically back
to where we were performance-wise.

Reported by Christophe Thommeret.

diff --git a/effect_chain.cpp b/effect_chain.cpp
index c5e10e84a39c2315773315c8ae871e05342e012c..8d3c61d27f4293eed70e9b5dfd4b02e6af9e9bbf 100644 (file)
--- a/effect_chain.cpp
+++ b/effect_chain.cpp
@@ -59,6 +59,11 @@ EffectChain::~EffectChain()
        if (owns_resource_pool) {
                delete resource_pool;
        }
+       for (map<void *, GLuint>::const_iterator fbo_it = fbos.begin();
+            fbo_it != fbos.end(); ++fbo_it) {
+               glDeleteFramebuffers(1, &fbo_it->second);
+               check_error();
+       }
 }
 
 Input *EffectChain::add_input(Input *input)
@@ -1405,6 +1410,7 @@ void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height
        // Save original viewport.
        GLuint x = 0, y = 0;
        GLuint fbo = 0;
+       void *context = get_gl_context_identifier();
 
        if (width == 0 && height == 0) {
                GLint viewport[4];
@@ -1424,8 +1430,13 @@ void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height
        check_error();
 
        if (phases.size() > 1) {
-               glGenFramebuffers(1, &fbo);
-               check_error();
+               if (fbos.count(context) == 0) {
+                       glGenFramebuffers(1, &fbo);
+                       check_error();
+                       fbos.insert(make_pair(context, fbo));
+               } else {
+                       fbo = fbos[context];
+               }
                glBindFramebuffer(GL_FRAMEBUFFER, fbo);
                check_error();
        }
@@ -1564,11 +1575,6 @@ void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height
 
        glBindFramebuffer(GL_FRAMEBUFFER, 0);
        check_error();
-
-       if (fbo != 0) {
-               glDeleteFramebuffers(1, &fbo);
-               check_error();
-       }
 }
 
 }  // namespace movit

diff --git a/effect_chain.h b/effect_chain.h
index 59949491e668eba68ec21202f8779d7dd6967ab4..505e55a26a0b80d3e4492786d8d046530b6ed329 100644 (file)
--- a/effect_chain.h
+++ b/effect_chain.h
@@ -280,6 +280,7 @@ private:
        std::map<Effect *, Node *> node_map;
        Effect *dither_effect;
 
+       std::map<void *, GLuint> fbos;  // One for each OpenGL context.
        std::vector<Input *> inputs;  // Also contained in nodes.
        std::vector<Phase *> phases;
 

diff --git a/util.cpp b/util.cpp
index 310e7be7f6627bf58fc5f5556712eafab4a3fa3f..1e66c30b573e51ef419146d5149c32ed9e53e7d3 100644 (file)
--- a/util.cpp
+++ b/util.cpp
@@ -9,6 +9,14 @@
 #include "init.h"
 #include "util.h"
 
+#if defined(__DARWIN__)
+#include <OpenGL/OpenGL.h>
+#elif defined(WIN32)
+#include <GL/wglew.h>
+#else
+#include <GL/glxew.h>
+#endif
+
 using namespace std;
 
 namespace movit {
@@ -233,4 +241,15 @@ unsigned next_power_of_two(unsigned v)
        return v;
 }
 
+void *get_gl_context_identifier()
+{
+#if defined(__DARWIN__)
+       return (void *)CGLGetCurrentContext();
+#elif defined(WIN32)
+       return (void *)wglGetCurrentContext();
+#else
+       return (void *)glXGetCurrentContext();
+#endif
+}
+
 }  // namespace movit

diff --git a/util.h b/util.h
index c5dafed6b7160f8b080ea6536608e1fd7735ee54..1ecdc00ce1b91dce58547b8d243fed8f3e4f3b3c 100644 (file)
--- a/util.h
+++ b/util.h
@@ -56,6 +56,12 @@ void cleanup_vertex_attribute(GLuint glsl_program_num, const std::string &attrib
 // If v is not already a power of two, return the first higher power of two.
 unsigned next_power_of_two(unsigned v);
 
+// Get a pointer that represents the current OpenGL context, in a cross-platform way.
+// This is not intended for anything but identification (ie., so you can associate
+// different FBOs with different contexts); you should probably not try to cast it
+// back into anything you intend to pass into OpenGL.
+void *get_gl_context_identifier();
+
 }  // namespace movit
 
 #ifdef NDEBUG