From 55481b3a2977179f47b6d8cec0700e0991dba462 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Wed, 15 Dec 2004 01:07:52 +0000 Subject: [PATCH] tweaks to the LIT instructions --- src/mesa/shader/nvvertexec.c | 13 ++++--------- src/mesa/swrast/s_nvfragprog.c | 12 +++++++----- 2 files changed, 11 insertions(+), 14 deletions(-) diff --git a/src/mesa/shader/nvvertexec.c b/src/mesa/shader/nvvertexec.c index 79929f1..269c4c9 100644 --- a/src/mesa/shader/nvvertexec.c +++ b/src/mesa/shader/nvvertexec.c @@ -412,17 +412,12 @@ _mesa_exec_vertex_program(GLcontext *ctx, const struct vertex_program *program) break; case VP_OPCODE_LIT: { - const GLfloat epsilon = 1.0e-5F; /* XXX fix? */ + const GLfloat epsilon = 1.0F / 256.0F; /* per NV spec */ GLfloat t[4], lit[4]; fetch_vector4( &inst->SrcReg[0], state, t ); - if (t[3] < -(128.0F - epsilon)) - t[3] = - (128.0F - epsilon); - else if (t[3] > 128.0F - epsilon) - t[3] = 128.0F - epsilon; - if (t[0] < 0.0) - t[0] = 0.0; - if (t[1] < 0.0) - t[1] = 0.0; + t[0] = MAX2(t[0], 0.0F); + t[1] = MAX2(t[1], 0.0F); + t[3] = CLAMP(t[3], -(128.0F - epsilon), (128.0F - epsilon)); lit[0] = 1.0; lit[1] = t[0]; lit[2] = (t[0] > 0.0) ? (GLfloat) exp(t[3] * log(t[1])) : 0.0F; diff --git a/src/mesa/swrast/s_nvfragprog.c b/src/mesa/swrast/s_nvfragprog.c index 88a6593..d083f83 100644 --- a/src/mesa/swrast/s_nvfragprog.c +++ b/src/mesa/swrast/s_nvfragprog.c @@ -1,6 +1,6 @@ /* * Mesa 3-D graphics library - * Version: 6.1 + * Version: 6.3 * * Copyright (C) 1999-2004 Brian Paul All Rights Reserved. * @@ -805,14 +805,16 @@ execute_program( GLcontext *ctx, break; case FP_OPCODE_LIT: { + const GLfloat epsilon = 1.0F / 256.0F; /* from NV VP spec */ GLfloat a[4], result[4]; fetch_vector4( ctx, &inst->SrcReg[0], machine, program, a ); - if (a[0] < 0.0F) - a[0] = 0.0F; - if (a[1] < 0.0F) - a[1] = 0.0F; + a[0] = MAX2(a[0], 0.0F); + a[1] = MAX2(a[1], 0.0F); + /* XXX ARB version clamps a[3], NV version doesn't */ + a[3] = CLAMP(a[3], -(128.0F - epsilon), (128.0F - epsilon)); result[0] = 1.0F; result[1] = a[0]; + /* XXX we could probably just use pow() here */ result[2] = (a[0] > 0.0F) ? (GLfloat) exp(a[3] * log(a[1])) : 0.0F; result[3] = 1.0F; store_vector4( inst, machine, result ); -- 2.7.4