vo_opengl: support HDR peak detection

This is done via compute shaders. As a consequence, the tone mapping
algorithms had to be rewritten to compute their known constants in GLSL
(ahead of time), instead of doing it once. Didn't affect performance.

Using shmem/SSBO atomics in this way is extremely fast on nvidia, but it
might be slow on other platforms. Needs testing.

Unfortunately, setting up the SSBO still requires OpenGL calls, which
means I can't have it in video_shaders.c, where it belongs. But I'll
defer worrying about that until the backend refactor, since then I'll be
breaking up the video/video_shaders structure anyway.

1 files changed, 1 insertions, 0 deletions

diff --git a/video/out/opengl/common.h b/video/out/opengl/common.h
index 40208c45e5..eec7806624 100644
--- a/video/out/opengl/common.h
+++ b/video/out/opengl/common.h
@@ -54,6 +54,7 @@ enum {
     MPGL_CAP_EXT16              = (1 << 18),    // GL_EXT_texture_norm16
     MPGL_CAP_ARB_FLOAT          = (1 << 19),    // GL_ARB_texture_float
     MPGL_CAP_EXT_CR_HFLOAT      = (1 << 20),    // GL_EXT_color_buffer_half_float
+    MPGL_CAP_SSBO               = (1 << 21),    // GL_ARB_shader_storage_buffer_object
 
     MPGL_CAP_SW                 = (1 << 30),    // indirect or sw renderer
 };