wined3d: Add support for EXT_texture_sRGB_decode.

dlls/wined3d/directx.c

@@ -129,6 +129,7 @@ static const struct {
     {"GL_EXT_texture_filter_anisotropic",   EXT_TEXTURE_FILTER_ANISOTROPIC, 0                           },
     {"GL_EXT_texture_lod_bias",             EXT_TEXTURE_LOD_BIAS,           0                           },
     {"GL_EXT_texture_sRGB",                 EXT_TEXTURE_SRGB,               0                           },
+    {"GL_EXT_texture_sRGB_decode",          EXT_TEXTURE_SRGB_DECODE,        0                           },
     {"GL_EXT_vertex_array_bgra",            EXT_VERTEX_ARRAY_BGRA,          0                           },
 
     /* NV */

dlls/wined3d/wined3d_gl.h

@@ -1810,6 +1810,7 @@ typedef enum wined3d_gl_extension
     EXT_TEXTURE_FILTER_ANISOTROPIC,
     EXT_TEXTURE_LOD_BIAS,
     EXT_TEXTURE_SRGB,
+    EXT_TEXTURE_SRGB_DECODE,
     EXT_VERTEX_ARRAY_BGRA,
     /* NVIDIA */
     NV_DEPTH_CLAMP,
@@ -3412,6 +3413,14 @@ typedef void (WINE_GLAPI *PGLFNGETCOMPRESSEDTEXIMAGEPROC)(GLenum target, GLint l
 #define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT              0x8c4f
 #endif
 
+/* GL_EXT_texture_sRGB_decode */
+#ifndef GL_EXT_texture_sRGB_decode
+#define GL_EXT_texture_sRGB_decode 1
+#define GL_TEXTURE_SRGB_DECODE_EXT                          0x8a48
+#define GL_DECODE_EXT                                       0x8a49
+#define GL_SKIP_DECODE_EXT                                  0x8a4a
+#endif
+
 /* GL_NV_depth_clamp */
 #ifndef GL_NV_depth_clamp
 #define GL_NV_depth_clamp 1