From 04dca296e0a5e5ffbb8acb699e013a23ebd7b645 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Thu, 20 Jan 2011 12:05:38 -0800 Subject: [PATCH] mesa: Set correct values for range/precision of shader integer types --- src/mesa/main/context.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c index fe370fa..e017939 100644 --- a/src/mesa/main/context.c +++ b/src/mesa/main/context.c @@ -534,8 +534,17 @@ init_program_limits(GLenum type, struct gl_program_constants *prog) prog->MediumFloat.RangeMax = 127; prog->MediumFloat.Precision = 23; prog->LowFloat = prog->HighFloat = prog->MediumFloat; - /* assume ints are stored as floats for now */ - prog->LowInt = prog->MediumInt = prog->HighInt = prog->MediumFloat; + + /* Assume ints are stored as floats for now, since this is the least-common + * denominator. The OpenGL ES spec implies (page 132) that the precision + * of integer types should be 0. Practically speaking, IEEE + * single-precision floating point values can only store integers in the + * range [-0x01000000, 0x01000000] without loss of precision. + */ + prog->MediumInt.RangeMin = 24; + prog->MediumInt.RangeMax = 24; + prog->MediumInt.Precision = 0; + prog->LowInt = prog->HighInt = prog->MediumInt; } -- 2.7.4