summaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
authorBrian Paul <brian.paul@tungstengraphics.com>1999-10-20 22:32:02 +0000
committerBrian Paul <brian.paul@tungstengraphics.com>1999-10-20 22:32:02 +0000
commit34c7c1838aa0e410ee9b62f8a04ed8b48e6a968b (patch)
treec3c755c759880d8203999bc645782c7c6f0405b9 /src
parent2c318aad9ddc67506e16c6c2b42e0f0d2edcfe41 (diff)
fixed divTable precision problem in GL_RETURN case
Diffstat (limited to 'src')
-rw-r--r--src/mesa/main/accum.c74
1 files changed, 46 insertions, 28 deletions
diff --git a/src/mesa/main/accum.c b/src/mesa/main/accum.c
index b7bb3f6e85..de660a84a6 100644
--- a/src/mesa/main/accum.c
+++ b/src/mesa/main/accum.c
@@ -1,4 +1,4 @@
-/* $Id: accum.c,v 1.6 1999/10/13 18:42:49 brianp Exp $ */
+/* $Id: accum.c,v 1.7 1999/10/20 22:32:02 brianp Exp $ */
/*
* Mesa 3-D graphics library
@@ -74,6 +74,9 @@
*/
+#define USE_OPTIMIZED_ACCUM /* enable the optimization */
+
+
void gl_alloc_accum_buffer( GLcontext *ctx )
{
@@ -91,7 +94,11 @@ void gl_alloc_accum_buffer( GLcontext *ctx )
/* unable to setup accumulation buffer */
gl_error( ctx, GL_OUT_OF_MEMORY, "glAccum" );
}
+#ifdef USE_OPTIMIZED_ACCUM
ctx->IntegerAccumMode = GL_TRUE;
+#else
+ ctx->IntegerAccumMode = GL_FALSE;
+#endif
ctx->IntegerAccumScaler = 0.0;
}
@@ -118,12 +125,12 @@ void gl_ClearAccum( GLcontext *ctx,
static void rescale_accum( GLcontext *ctx )
{
const GLuint n = ctx->Buffer->Width * ctx->Buffer->Height * 4;
- const GLfloat s = ctx->IntegerAccumScaler * (32767.0 / 255.0);
+ const GLfloat fChanMax = (1 << (sizeof(GLchan) * 8)) - 1;
+ const GLfloat s = ctx->IntegerAccumScaler * (32767.0 / fChanMax);
GLaccum *accum = ctx->Buffer->Accum;
GLuint i;
assert(ctx->IntegerAccumMode);
- assert(sizeof(GLchan) == 1); /* if not true, 255.0 above must be fixed */
assert(accum);
for (i = 0; i < n; i++) {
@@ -140,6 +147,8 @@ void gl_Accum( GLcontext *ctx, GLenum op, GLfloat value )
GLuint xpos, ypos, width, height, width4;
GLfloat acc_scale;
GLubyte rgba[MAX_WIDTH][4];
+ const GLint iChanMax = (1 << (sizeof(GLchan) * 8)) - 1;
+ const GLfloat fChanMax = (1 << (sizeof(GLchan) * 8)) - 1;
ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glAccum");
@@ -185,7 +194,7 @@ void gl_Accum( GLcontext *ctx, GLenum op, GLfloat value )
{
const GLaccum intVal = (GLaccum) (value * acc_scale);
GLuint j;
- /* May have to leave optimized accum buffer mode */
+ /* Leave optimized accum buffer mode */
if (ctx->IntegerAccumMode)
rescale_accum(ctx);
for (j = 0; j < height; j++) {
@@ -202,7 +211,7 @@ void gl_Accum( GLcontext *ctx, GLenum op, GLfloat value )
case GL_MULT:
{
GLuint j;
- /* May have to leave optimized accum buffer mode */
+ /* Leave optimized accum buffer mode */
if (ctx->IntegerAccumMode)
rescale_accum(ctx);
for (j = 0; j < height; j++) {
@@ -247,10 +256,10 @@ void gl_Accum( GLcontext *ctx, GLenum op, GLfloat value )
}
else {
/* scaled integer accum buffer */
- const GLfloat rscale = value * acc_scale / 255.0;
- const GLfloat gscale = value * acc_scale / 255.0;
- const GLfloat bscale = value * acc_scale / 255.0;
- const GLfloat ascale = value * acc_scale / 255.0;
+ const GLfloat rscale = value * acc_scale / fChanMax;
+ const GLfloat gscale = value * acc_scale / fChanMax;
+ const GLfloat bscale = value * acc_scale / fChanMax;
+ const GLfloat ascale = value * acc_scale / fChanMax;
GLuint j;
for (j=0;j<height;j++) {
GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos * 4;
@@ -273,7 +282,11 @@ void gl_Accum( GLcontext *ctx, GLenum op, GLfloat value )
/* This is a change to go into optimized accum buffer mode */
if (value > 0.0 && value <= 1.0) {
+#ifdef USE_OPTIMIZED_ACCUM
ctx->IntegerAccumMode = GL_TRUE;
+#else
+ ctx->IntegerAccumMode = GL_FALSE;
+#endif
ctx->IntegerAccumScaler = value;
}
else {
@@ -302,19 +315,20 @@ void gl_Accum( GLcontext *ctx, GLenum op, GLfloat value )
}
else {
/* scaled integer accum buffer */
- const GLfloat rscale = value * acc_scale / 255.0;
- const GLfloat gscale = value * acc_scale / 255.0;
- const GLfloat bscale = value * acc_scale / 255.0;
- const GLfloat ascale = value * acc_scale / 255.0;
+ const GLfloat rscale = value * acc_scale / fChanMax;
+ const GLfloat gscale = value * acc_scale / fChanMax;
+ const GLfloat bscale = value * acc_scale / fChanMax;
+ const GLfloat ascale = value * acc_scale / fChanMax;
+ const GLfloat d = 3.0 / acc_scale;
GLuint i, j;
for (j = 0; j < height; j++) {
GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos * 4;
gl_read_rgba_span(ctx, width, xpos, ypos, rgba);
for (i=0;i<width;i++) {
- *acc++ = (GLaccum) ( (GLfloat) rgba[i][RCOMP] * rscale );
- *acc++ = (GLaccum) ( (GLfloat) rgba[i][GCOMP] * gscale );
- *acc++ = (GLaccum) ( (GLfloat) rgba[i][BCOMP] * bscale );
- *acc++ = (GLaccum) ( (GLfloat) rgba[i][ACOMP] * ascale );
+ *acc++ = (GLaccum) ((GLfloat) rgba[i][RCOMP] * rscale + d);
+ *acc++ = (GLaccum) ((GLfloat) rgba[i][GCOMP] * gscale + d);
+ *acc++ = (GLaccum) ((GLfloat) rgba[i][BCOMP] * bscale + d);
+ *acc++ = (GLaccum) ((GLfloat) rgba[i][ACOMP] * ascale + d);
}
ypos++;
}
@@ -329,14 +343,14 @@ void gl_Accum( GLcontext *ctx, GLenum op, GLfloat value )
if (ctx->IntegerAccumMode) {
/* build lookup table to avoid integer divides */
- GLint divisor = (GLint) ((1.0F / ctx->IntegerAccumScaler) + 0.5F);
+ GLfloat divisor = 1.0F / ctx->IntegerAccumScaler;
static GLubyte divTable[32768];
- static GLint prevDivisor = 0.0;
+ static GLfloat prevDivisor = 0.0;
GLuint j;
if (divisor != prevDivisor) {
assert(divisor * 256 <= 32768);
for (j = 0; j < divisor * 256; j++)
- divTable[j] = j / divisor;
+ divTable[j] = (GLint) ((GLfloat) j / divisor + 0.5F);
prevDivisor = divisor;
}
@@ -364,10 +378,10 @@ void gl_Accum( GLcontext *ctx, GLenum op, GLfloat value )
}
}
else {
- const GLfloat rscale = value / acc_scale * 255.0F;
- const GLfloat gscale = value / acc_scale * 255.0F;
- const GLfloat bscale = value / acc_scale * 255.0F;
- const GLfloat ascale = value / acc_scale * 255.0F;
+ const GLfloat rscale = value / acc_scale * fChanMax;
+ const GLfloat gscale = value / acc_scale * fChanMax;
+ const GLfloat bscale = value / acc_scale * fChanMax;
+ const GLfloat ascale = value / acc_scale * fChanMax;
GLuint i, j;
for (j=0;j<height;j++) {
const GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos*4;
@@ -377,10 +391,10 @@ void gl_Accum( GLcontext *ctx, GLenum op, GLfloat value )
g = (GLint) ( (GLfloat) (*acc++) * gscale + 0.5F );
b = (GLint) ( (GLfloat) (*acc++) * bscale + 0.5F );
a = (GLint) ( (GLfloat) (*acc++) * ascale + 0.5F );
- rgba[i][RCOMP] = CLAMP( r, 0, 255 );
- rgba[i][GCOMP] = CLAMP( g, 0, 255 );
- rgba[i][BCOMP] = CLAMP( b, 0, 255 );
- rgba[i][ACOMP] = CLAMP( a, 0, 255 );
+ rgba[i][RCOMP] = CLAMP( r, 0, iChanMax );
+ rgba[i][GCOMP] = CLAMP( g, 0, iChanMax );
+ rgba[i][BCOMP] = CLAMP( b, 0, iChanMax );
+ rgba[i][ACOMP] = CLAMP( a, 0, iChanMax );
}
if (ctx->Color.SWmasking) {
gl_mask_rgba_span( ctx, width, xpos, ypos, rgba );
@@ -491,7 +505,11 @@ void gl_clear_accum_buffer( GLcontext *ctx )
/* update optimized accum state vars */
if (ctx->Accum.ClearColor[0] == 0.0 && ctx->Accum.ClearColor[1] == 0.0 &&
ctx->Accum.ClearColor[2] == 0.0 && ctx->Accum.ClearColor[3] == 0.0) {
+#ifdef USE_OPTIMIZED_ACCUM
ctx->IntegerAccumMode = GL_TRUE;
+#else
+ ctx->IntegerAccumMode = GL_FALSE;
+#endif
ctx->IntegerAccumScaler = 0.0; /* denotes empty accum buffer */
}
else {