src/mesa/swrast/s_imaging.c

   1 /* $Id: s_imaging.c,v 1.1 2000/10/31 18:00:04 keithw Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.4
   6  *
   7  * Copyright (C) 1999-2000  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28 /*
  29  * Histogram, Min/max and convolution for GL_ARB_imaging subset
  30  *
  31  */
  32
  33
  34 #include "glheader.h"
  35 #include "colormac.h"
  36 #include "image.h"
  37 #include "mmath.h"
  38
  39 #include "s_imaging.h"
  40 #include "s_span.h"
  41
  42
  43
  44 /*
  45  * Update the min/max values from an array of fragment colors.
  46  */
  47 void
  48 _mesa_update_minmax(GLcontext *ctx, GLuint n, const GLfloat rgba[][4])
  49 {
  50    GLuint i;
  51    for (i = 0; i < n; i++) {
  52       /* update mins */
  53       if (rgba[i][RCOMP] < ctx->MinMax.Min[RCOMP])
  54          ctx->MinMax.Min[RCOMP] = rgba[i][RCOMP];
  55       if (rgba[i][GCOMP] < ctx->MinMax.Min[GCOMP])
  56          ctx->MinMax.Min[GCOMP] = rgba[i][GCOMP];
  57       if (rgba[i][BCOMP] < ctx->MinMax.Min[BCOMP])
  58          ctx->MinMax.Min[BCOMP] = rgba[i][BCOMP];
  59       if (rgba[i][ACOMP] < ctx->MinMax.Min[ACOMP])
  60          ctx->MinMax.Min[ACOMP] = rgba[i][ACOMP];
  61
  62       /* update maxs */
  63       if (rgba[i][RCOMP] > ctx->MinMax.Max[RCOMP])
  64          ctx->MinMax.Max[RCOMP] = rgba[i][RCOMP];
  65       if (rgba[i][GCOMP] > ctx->MinMax.Max[GCOMP])
  66          ctx->MinMax.Max[GCOMP] = rgba[i][GCOMP];
  67       if (rgba[i][BCOMP] > ctx->MinMax.Max[BCOMP])
  68          ctx->MinMax.Max[BCOMP] = rgba[i][BCOMP];
  69       if (rgba[i][ACOMP] > ctx->MinMax.Max[ACOMP])
  70          ctx->MinMax.Max[ACOMP] = rgba[i][ACOMP];
  71    }
  72 }
  73
  74
  75 /*
  76  * Update the histogram values from an array of fragment colors.
  77  */
  78 void
  79 _mesa_update_histogram(GLcontext *ctx, GLuint n, const GLfloat rgba[][4])
  80 {
  81    const GLint max = ctx->Histogram.Width - 1;
  82    GLfloat w = (GLfloat) max;
  83    GLuint i;
  84
  85    if (ctx->Histogram.Width == 0)
  86       return;
  87
  88    for (i = 0; i < n; i++) {
  89       GLint ri = (GLint) (rgba[i][RCOMP] * w + 0.5F);
  90       GLint gi = (GLint) (rgba[i][GCOMP] * w + 0.5F);
  91       GLint bi = (GLint) (rgba[i][BCOMP] * w + 0.5F);
  92       GLint ai = (GLint) (rgba[i][ACOMP] * w + 0.5F);
  93       ri = CLAMP(ri, 0, max);
  94       gi = CLAMP(gi, 0, max);
  95       bi = CLAMP(bi, 0, max);
  96       ai = CLAMP(ai, 0, max);
  97       ctx->Histogram.Count[ri][RCOMP]++;
  98       ctx->Histogram.Count[gi][GCOMP]++;
  99       ctx->Histogram.Count[bi][BCOMP]++;
 100       ctx->Histogram.Count[ai][ACOMP]++;
 101    }
 102 }
 103
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