X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=init.h;h=9b4deff5c7a36bb256b93ba199b5c8862c55f961;hp=7cee8587758331566d1b5b7e57db20e6f25aa2ab;hb=03b416172e9db37845b8c897d51064cbc6b3aa3f;hpb=49ef2523611e215b327cd26f7bf698d1516edd46

diff --git a/init.h b/init.h
index 7cee858..9b4deff 100644
--- a/init.h
+++ b/init.h
@@ -1,5 +1,5 @@
-#ifndef _INIT_H
-#define _INIT_H
+#ifndef _MOVIT_INIT_H
+#define _MOVIT_INIT_H
 
 #include <string>
 
@@ -44,7 +44,18 @@ extern MovitDebugLevel movit_debug_level;
 // We currently don't bother to test for more than 1024 levels.
 extern float movit_texel_subpixel_precision;
 
+// Some GPUs use very inaccurate fixed-function circuits for rounding
+// floating-point values to 8-bit outputs, leading to absurdities like
+// the roundoff point between 128 and 129 being 128.62 instead of 128.6.
+// We test, for every integer, x+0.48 and x+0.52 and check that they
+// round the right way (giving some leeway, but not a lot); the number
+// of errors are stored here.
+//
+// If this value is above 0, and you have enabled dithering, we will
+// round off explicitly at the very end of the shader.
+extern int movit_num_wrongly_rounded;
+
 // Whether the GPU in use supports GL_EXT_texture_sRGB.
 extern bool movit_srgb_textures_supported;
 
-#endif  // !defined(_INIT_H)
+#endif  // !defined(_MOVIT_INIT_H)