Initial revision

1 files changed, 495 insertions, 0 deletions

diff --git a/src/mesa/main/accum.c b/src/mesa/main/accum.c
new file mode 100644
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+/* $Id: accum.c,v 1.1 1999/08/19 00:55:41 jtg Exp $ */
+
+/*
+ * Mesa 3-D graphics library
+ * Version:  3.1
+ * 
+ * Copyright (C) 1999  Brian Paul   All Rights Reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+#ifdef PC_HEADER
+#include "all.h"
+#else
+#include <assert.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include "accum.h"
+#include "context.h"
+#include "macros.h"
+#include "masking.h"
+#include "span.h"
+#include "types.h"
+#ifdef XFree86Server
+#include "GL/xf86glx.h"
+#endif
+#endif
+
+
+/*
+ * Accumulation buffer notes
+ *
+ * Normally, accumulation buffer values are GLshorts with values in
+ * [-32767, 32767] which represent floating point colors in [-1, 1],
+ * as suggested by the OpenGL specification.
+ *
+ * We optimize for the common case used for full-scene antialiasing:
+ *    // start with accum buffer cleared to zero
+ *    glAccum(GL_LOAD, w);   // or GL_ACCUM the first image
+ *    glAccum(GL_ACCUM, w);
+ *    ...
+ *    glAccum(GL_ACCUM, w);
+ *    glAccum(GL_RETURN, 1.0);
+ * That is, we start with an empty accumulation buffer and accumulate
+ * n images, each with weight w = 1/n.
+ * In this scenario, we can simply store unscaled integer values in
+ * the accum buffer instead of scaled integers.  We'll also keep track
+ * of the w value so when we do GL_RETURN we simply divide the accumulated
+ * values by n (=1/w).
+ * This lets us avoid _many_ int->float->int conversions.
+ */
+
+
+
+void gl_alloc_accum_buffer( GLcontext *ctx )
+{
+   GLint n;
+
+   if (ctx->Buffer->Accum) {
+      free( ctx->Buffer->Accum );
+      ctx->Buffer->Accum = NULL;
+   }
+
+   /* allocate accumulation buffer if not already present */
+   n = ctx->Buffer->Width * ctx->Buffer->Height * 4 * sizeof(GLaccum);
+   ctx->Buffer->Accum = (GLaccum *) malloc( n );
+   if (!ctx->Buffer->Accum) {
+      /* unable to setup accumulation buffer */
+      gl_error( ctx, GL_OUT_OF_MEMORY, "glAccum" );
+   }
+   ctx->IntegerAccumMode = GL_TRUE;
+   ctx->IntegerAccumScaler = 0.0;
+}
+
+
+
+void gl_ClearAccum( GLcontext *ctx,
+                    GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha )
+{
+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glAccum");
+
+   ctx->Accum.ClearColor[0] = CLAMP( red, -1.0, 1.0 );
+   ctx->Accum.ClearColor[1] = CLAMP( green, -1.0, 1.0 );
+   ctx->Accum.ClearColor[2] = CLAMP( blue, -1.0, 1.0 );
+   ctx->Accum.ClearColor[3] = CLAMP( alpha, -1.0, 1.0 );
+}
+
+
+
+/*
+ * This is called when we fall out of optimized/unscaled accum buffer mode.
+ * That is, we convert each unscaled accum buffer value into a scaled value
+ * representing the range[-1, 1].
+ */
+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);
+   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++) {
+      accum[i] = (GLaccum) (accum[i] * s);
+   }
+
+   ctx->IntegerAccumMode = GL_FALSE;
+}
+
+
+
+void gl_Accum( GLcontext *ctx, GLenum op, GLfloat value )
+{
+   GLuint xpos, ypos, width, height, width4;
+   GLfloat acc_scale;
+   GLubyte rgba[MAX_WIDTH][4];
+   
+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glAccum");
+
+   if (ctx->Visual->AccumBits==0 || !ctx->Buffer->Accum) {
+      /* No accumulation buffer! */
+      gl_warning(ctx, "Calling glAccum() without an accumulation buffer");
+      return;
+   }
+
+   if (sizeof(GLaccum)==1) {
+      acc_scale = 127.0;
+   }
+   else if (sizeof(GLaccum)==2) {
+      acc_scale = 32767.0;
+   }
+   else {
+      /* sizeof(GLaccum) > 2 (Cray) */
+      acc_scale = (float) SHRT_MAX;
+   }
+
+   if (ctx->NewState)
+      gl_update_state( ctx );
+
+   /* Determine region to operate upon. */
+   if (ctx->Scissor.Enabled) {
+      xpos = ctx->Scissor.X;
+      ypos = ctx->Scissor.Y;
+      width = ctx->Scissor.Width;
+      height = ctx->Scissor.Height;
+   }
+   else {
+      /* whole window */
+      xpos = 0;
+      ypos = 0;
+      width = ctx->Buffer->Width;
+      height = ctx->Buffer->Height;
+   }
+
+   width4 = 4 * width;
+
+   switch (op) {
+      case GL_ADD:
+         {
+	    const GLaccum intVal = (GLaccum) (value * acc_scale);
+	    GLuint j;
+            /* May have to leave optimized accum buffer mode */
+            if (ctx->IntegerAccumMode)
+               rescale_accum(ctx);
+	    for (j = 0; j < height; j++) {
+	       GLaccum * acc = ctx->Buffer->Accum + ypos * width4 + 4 * xpos;
+               GLuint i;
+	       for (i = 0; i < width4; i++) {
+                  acc[i] += intVal;
+	       }
+	       ypos++;
+	    }
+	 }
+	 break;
+
+      case GL_MULT:
+	 {
+	    GLuint j;
+            /* May have to leave optimized accum buffer mode */
+            if (ctx->IntegerAccumMode)
+               rescale_accum(ctx);
+	    for (j = 0; j < height; j++) {
+	       GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + 4 * xpos;
+               GLuint i;
+	       for (i = 0; i < width4; i++) {
+                  acc[i] = (GLaccum) ( (GLfloat) acc[i] * value );
+	       }
+	       ypos++;
+	    }
+	 }
+	 break;
+
+      case GL_ACCUM:
+         (void) (*ctx->Driver.SetBuffer)( ctx, ctx->Pixel.DriverReadBuffer );
+
+         /* May have to leave optimized accum buffer mode */
+         if (ctx->IntegerAccumScaler == 0.0 && value > 0.0 && value <= 1.0)
+            ctx->IntegerAccumScaler = value;
+         if (ctx->IntegerAccumMode && value != ctx->IntegerAccumScaler)
+            rescale_accum(ctx);
+            
+         if (ctx->IntegerAccumMode) {
+            /* simply add integer color values into accum buffer */
+            GLuint j;
+            GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos * 4;
+            assert(ctx->IntegerAccumScaler > 0.0);
+            assert(ctx->IntegerAccumScaler <= 1.0);
+            for (j = 0; j < height; j++) {
+               
+               GLuint i, i4;
+               gl_read_rgba_span(ctx, width, xpos, ypos, rgba);
+               for (i = i4 = 0; i < width; i++, i4+=4) {
+                  acc[i4+0] += rgba[i][RCOMP];
+                  acc[i4+1] += rgba[i][GCOMP];
+                  acc[i4+2] += rgba[i][BCOMP];
+                  acc[i4+3] += rgba[i][ACOMP];
+               }
+               acc += width4;
+               ypos++;
+            }
+         }
+         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;
+            GLuint j;
+            for (j=0;j<height;j++) {
+               GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos * 4;
+               GLuint i;
+               gl_read_rgba_span(ctx, width, xpos, ypos, rgba);
+               for (i=0;i<width;i++) {
+                  *acc += (GLaccum) ( (GLfloat) rgba[i][RCOMP] * rscale );  acc++;
+                  *acc += (GLaccum) ( (GLfloat) rgba[i][GCOMP] * gscale );  acc++;
+                  *acc += (GLaccum) ( (GLfloat) rgba[i][BCOMP] * bscale );  acc++;
+                  *acc += (GLaccum) ( (GLfloat) rgba[i][ACOMP] * ascale );  acc++;
+               }
+               ypos++;
+            }
+         }
+         (void) (*ctx->Driver.SetBuffer)( ctx, ctx->Color.DriverDrawBuffer );
+	 break;
+
+      case GL_LOAD:
+         (void) (*ctx->Driver.SetBuffer)( ctx, ctx->Pixel.DriverReadBuffer );
+
+         /* This is a change to go into optimized accum buffer mode */
+         if (value > 0.0 && value <= 1.0) {
+            ctx->IntegerAccumMode = GL_TRUE;
+            ctx->IntegerAccumScaler = value;
+         }
+         else {
+            ctx->IntegerAccumMode = GL_FALSE;
+            ctx->IntegerAccumScaler = 0.0;
+         }
+
+         if (ctx->IntegerAccumMode) {
+            /* just copy values into accum buffer */
+            GLuint j;
+            GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos * 4;
+            assert(ctx->IntegerAccumScaler > 0.0);
+            assert(ctx->IntegerAccumScaler <= 1.0);
+            for (j = 0; j < height; j++) {
+               GLuint i, i4;
+               gl_read_rgba_span(ctx, width, xpos, ypos, rgba);
+               for (i = i4 = 0; i < width; i++, i4 += 4) {
+                  acc[i4+0] = rgba[i][RCOMP];
+                  acc[i4+1] = rgba[i][GCOMP];
+                  acc[i4+2] = rgba[i][BCOMP];
+                  acc[i4+3] = rgba[i][ACOMP];
+               }
+               acc += width4;
+               ypos++;
+            }
+         }
+         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;
+            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 );
+               }
+               ypos++;
+            }
+         }
+         (void) (*ctx->Driver.SetBuffer)( ctx, ctx->Color.DriverDrawBuffer );
+	 break;
+
+      case GL_RETURN:
+         /* May have to leave optimized accum buffer mode */
+         if (ctx->IntegerAccumMode && value != 1.0)
+            rescale_accum(ctx);
+
+         if (ctx->IntegerAccumMode) {
+            /* build lookup table to avoid integer divides */
+            GLint divisor = (GLint) ((1.0F / ctx->IntegerAccumScaler) + 0.5F);
+            static GLubyte divTable[32768];
+            static GLint prevDivisor = 0.0;
+            GLuint j;
+            if (divisor != prevDivisor) {
+               assert(divisor * 256 <= 32768);
+               for (j = 0; j < divisor * 256; j++)
+                  divTable[j] = j / divisor;
+               prevDivisor = divisor;
+            }
+
+            assert(ctx->IntegerAccumScaler > 0.0);
+            assert(ctx->IntegerAccumScaler <= 1.0);
+            for (j = 0; j < height; j++) {
+               const GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos*4;
+               GLuint i, i4;
+               for (i = i4 = 0; i < width; i++, i4 += 4) {
+                  ASSERT(acc[i4+0] < divisor * 256);
+                  ASSERT(acc[i4+1] < divisor * 256);
+                  ASSERT(acc[i4+2] < divisor * 256);
+                  ASSERT(acc[i4+3] < divisor * 256);
+                  rgba[i][RCOMP] = divTable[acc[i4+0]];
+                  rgba[i][GCOMP] = divTable[acc[i4+1]];
+                  rgba[i][BCOMP] = divTable[acc[i4+2]];
+                  rgba[i][ACOMP] = divTable[acc[i4+3]];
+               }
+               if (ctx->Color.SWmasking) {
+                  gl_mask_rgba_span( ctx, width, xpos, ypos, rgba );
+               }
+               (*ctx->Driver.WriteRGBASpan)( ctx, width, xpos, ypos, 
+                                             (const GLubyte (*)[4])rgba, NULL );
+               ypos++;
+            }
+         }
+         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;
+            GLuint i, j;
+            for (j=0;j<height;j++) {
+               const GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos*4;
+               for (i=0;i<width;i++) {
+                  GLint r, g, b, a;
+                  r = (GLint) ( (GLfloat) (*acc++) * rscale + 0.5F );
+                  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 );
+               }
+               if (ctx->Color.SWmasking) {
+                  gl_mask_rgba_span( ctx, width, xpos, ypos, rgba );
+               }
+               (*ctx->Driver.WriteRGBASpan)( ctx, width, xpos, ypos, 
+                                             (const GLubyte (*)[4])rgba, NULL );
+               ypos++;
+            }
+	 }
+	 break;
+
+      default:
+         gl_error( ctx, GL_INVALID_ENUM, "glAccum" );
+   }
+}
+
+
+
+/*
+ * Clear the accumulation Buffer.
+ */
+void gl_clear_accum_buffer( GLcontext *ctx )
+{
+   GLuint buffersize;
+   GLfloat acc_scale;
+
+   if (ctx->Visual->AccumBits==0) {
+      /* No accumulation buffer! */
+      return;
+   }
+
+   if (sizeof(GLaccum)==1) {
+      acc_scale = 127.0;
+   }
+   else if (sizeof(GLaccum)==2) {
+      acc_scale = 32767.0;
+   }
+   else {
+      /* sizeof(GLaccum) > 2 (Cray) */
+      acc_scale = (float) SHRT_MAX;
+   }
+
+   /* number of pixels */
+   buffersize = ctx->Buffer->Width * ctx->Buffer->Height;
+
+   if (!ctx->Buffer->Accum) {
+      /* try to alloc accumulation buffer */
+      ctx->Buffer->Accum = (GLaccum *)
+	                   malloc( buffersize * 4 * sizeof(GLaccum) );
+   }
+
+   if (ctx->Buffer->Accum) {
+      if (ctx->Scissor.Enabled) {
+	 /* Limit clear to scissor box */
+	 GLaccum r, g, b, a;
+	 GLint i, j;
+         GLint width, height;
+         GLaccum *row;
+	 r = (GLaccum) (ctx->Accum.ClearColor[0] * acc_scale);
+	 g = (GLaccum) (ctx->Accum.ClearColor[1] * acc_scale);
+	 b = (GLaccum) (ctx->Accum.ClearColor[2] * acc_scale);
+	 a = (GLaccum) (ctx->Accum.ClearColor[3] * acc_scale);
+         /* size of region to clear */
+         width = 4 * (ctx->Buffer->Xmax - ctx->Buffer->Xmin + 1);
+         height = ctx->Buffer->Ymax - ctx->Buffer->Ymin + 1;
+         /* ptr to first element to clear */
+         row = ctx->Buffer->Accum
+               + 4 * (ctx->Buffer->Ymin * ctx->Buffer->Width
+                      + ctx->Buffer->Xmin);
+         for (j=0;j<height;j++) {
+            for (i=0;i<width;i+=4) {
+               row[i+0] = r;
+               row[i+1] = g;
+               row[i+2] = b;
+               row[i+3] = a;
+	    }
+            row += 4 * ctx->Buffer->Width;
+	 }
+      }
+      else {
+	 /* clear whole buffer */
+	 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) {
+	    /* Black */
+	    MEMSET( ctx->Buffer->Accum, 0, buffersize * 4 * sizeof(GLaccum) );
+	 }
+	 else {
+	    /* Not black */
+	    GLaccum *acc, r, g, b, a;
+	    GLuint i;
+
+	    acc = ctx->Buffer->Accum;
+	    r = (GLaccum) (ctx->Accum.ClearColor[0] * acc_scale);
+	    g = (GLaccum) (ctx->Accum.ClearColor[1] * acc_scale);
+	    b = (GLaccum) (ctx->Accum.ClearColor[2] * acc_scale);
+	    a = (GLaccum) (ctx->Accum.ClearColor[3] * acc_scale);
+	    for (i=0;i<buffersize;i++) {
+	       *acc++ = r;
+	       *acc++ = g;
+	       *acc++ = b;
+	       *acc++ = a;
+	    }
+	 }
+      }
+
+      /* 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) {
+         ctx->IntegerAccumMode = GL_TRUE;
+         ctx->IntegerAccumScaler = 0.0;  /* denotes empty accum buffer */
+      }
+      else {
+         ctx->IntegerAccumMode = GL_FALSE;
+      }
+   }
+}