mesa/main/pixeltransfer.c

/*
 * Mesa 3-D graphics library
 *
 * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
 * Copyright (C) 2009-2010  VMware, Inc.  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
 * THE AUTHORS 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.
 */


/**
 * \file pixeltransfer.c
 * Pixel transfer operations (scale, bias, table lookups, etc)
 */


#include "glheader.h"
#include "colormac.h"
#include "pixeltransfer.h"
#include "imports.h"
#include "mtypes.h"


/*
 * Apply scale and bias factors to an array of RGBA pixels.
 */
void
_mesa_scale_and_bias_rgba(GLuint n, GLfloat rgba[][4],
                          GLfloat rScale, GLfloat gScale,
                          GLfloat bScale, GLfloat aScale,
                          GLfloat rBias, GLfloat gBias,
                          GLfloat bBias, GLfloat aBias)
{
   if (rScale != 1.0 || rBias != 0.0) {
      GLuint i;
      for (i = 0; i < n; i++) {
         rgba[i][RCOMP] = rgba[i][RCOMP] * rScale + rBias;
      }
   }
   if (gScale != 1.0 || gBias != 0.0) {
      GLuint i;
      for (i = 0; i < n; i++) {
         rgba[i][GCOMP] = rgba[i][GCOMP] * gScale + gBias;
      }
   }
   if (bScale != 1.0 || bBias != 0.0) {
      GLuint i;
      for (i = 0; i < n; i++) {
         rgba[i][BCOMP] = rgba[i][BCOMP] * bScale + bBias;
      }
   }
   if (aScale != 1.0 || aBias != 0.0) {
      GLuint i;
      for (i = 0; i < n; i++) {
         rgba[i][ACOMP] = rgba[i][ACOMP] * aScale + aBias;
      }
   }
}


/*
 * Apply pixel mapping to an array of floating point RGBA pixels.
 */
void
_mesa_map_rgba( const struct gl_context *ctx, GLuint n, GLfloat rgba[][4] )
{
   const GLfloat rscale = (GLfloat) (ctx->PixelMaps.RtoR.Size - 1);
   const GLfloat gscale = (GLfloat) (ctx->PixelMaps.GtoG.Size - 1);
   const GLfloat bscale = (GLfloat) (ctx->PixelMaps.BtoB.Size - 1);
   const GLfloat ascale = (GLfloat) (ctx->PixelMaps.AtoA.Size - 1);
   const GLfloat *rMap = ctx->PixelMaps.RtoR.Map;
   const GLfloat *gMap = ctx->PixelMaps.GtoG.Map;
   const GLfloat *bMap = ctx->PixelMaps.BtoB.Map;
   const GLfloat *aMap = ctx->PixelMaps.AtoA.Map;
   GLuint i;
   for (i=0;i<n;i++) {
      GLfloat r = CLAMP(rgba[i][RCOMP], 0.0F, 1.0F);
      GLfloat g = CLAMP(rgba[i][GCOMP], 0.0F, 1.0F);
      GLfloat b = CLAMP(rgba[i][BCOMP], 0.0F, 1.0F);
      GLfloat a = CLAMP(rgba[i][ACOMP], 0.0F, 1.0F);
      rgba[i][RCOMP] = rMap[F_TO_I(r * rscale)];
      rgba[i][GCOMP] = gMap[F_TO_I(g * gscale)];
      rgba[i][BCOMP] = bMap[F_TO_I(b * bscale)];
      rgba[i][ACOMP] = aMap[F_TO_I(a * ascale)];
   }
}

/*
 * Map color indexes to float rgba values.
 */
void
_mesa_map_ci_to_rgba( const struct gl_context *ctx, GLuint n,
                      const GLuint index[], GLfloat rgba[][4] )
{
   GLuint rmask = ctx->PixelMaps.ItoR.Size - 1;
   GLuint gmask = ctx->PixelMaps.ItoG.Size - 1;
   GLuint bmask = ctx->PixelMaps.ItoB.Size - 1;
   GLuint amask = ctx->PixelMaps.ItoA.Size - 1;
   const GLfloat *rMap = ctx->PixelMaps.ItoR.Map;
   const GLfloat *gMap = ctx->PixelMaps.ItoG.Map;
   const GLfloat *bMap = ctx->PixelMaps.ItoB.Map;
   const GLfloat *aMap = ctx->PixelMaps.ItoA.Map;
   GLuint i;
   for (i=0;i<n;i++) {
      rgba[i][RCOMP] = rMap[index[i] & rmask];
      rgba[i][GCOMP] = gMap[index[i] & gmask];
      rgba[i][BCOMP] = bMap[index[i] & bmask];
      rgba[i][ACOMP] = aMap[index[i] & amask];
   }
}


void
_mesa_scale_and_bias_depth(const struct gl_context *ctx, GLuint n,
                           GLfloat depthValues[])
{
   const GLfloat scale = ctx->Pixel.DepthScale;
   const GLfloat bias = ctx->Pixel.DepthBias;
   GLuint i;
   for (i = 0; i < n; i++) {
      GLfloat d = depthValues[i] * scale + bias;
      depthValues[i] = CLAMP(d, 0.0F, 1.0F);
   }
}


void
_mesa_scale_and_bias_depth_uint(const struct gl_context *ctx, GLuint n,
                                GLuint depthValues[])
{
   const GLdouble max = (double) 0xffffffff;
   const GLdouble scale = ctx->Pixel.DepthScale;
   const GLdouble bias = ctx->Pixel.DepthBias * max;
   GLuint i;
   for (i = 0; i < n; i++) {
      GLdouble d = (GLdouble) depthValues[i] * scale + bias;
      d = CLAMP(d, 0.0, max);
      depthValues[i] = (GLuint) d;
   }
}

/**
 * Apply various pixel transfer operations to an array of RGBA pixels
 * as indicated by the transferOps bitmask
 */
void
_mesa_apply_rgba_transfer_ops(struct gl_context *ctx, GLbitfield transferOps,
                              GLuint n, GLfloat rgba[][4])
{
   /* scale & bias */
   if (transferOps & IMAGE_SCALE_BIAS_BIT) {
      _mesa_scale_and_bias_rgba(n, rgba,
                                ctx->Pixel.RedScale, ctx->Pixel.GreenScale,
                                ctx->Pixel.BlueScale, ctx->Pixel.AlphaScale,
                                ctx->Pixel.RedBias, ctx->Pixel.GreenBias,
                                ctx->Pixel.BlueBias, ctx->Pixel.AlphaBias);
   }
   /* color map lookup */
   if (transferOps & IMAGE_MAP_COLOR_BIT) {
      _mesa_map_rgba( ctx, n, rgba );
   }

   /* clamping to [0,1] */
   if (transferOps & IMAGE_CLAMP_BIT) {
      GLuint i;
      for (i = 0; i < n; i++) {
         rgba[i][RCOMP] = CLAMP(rgba[i][RCOMP], 0.0F, 1.0F);
         rgba[i][GCOMP] = CLAMP(rgba[i][GCOMP], 0.0F, 1.0F);
         rgba[i][BCOMP] = CLAMP(rgba[i][BCOMP], 0.0F, 1.0F);
         rgba[i][ACOMP] = CLAMP(rgba[i][ACOMP], 0.0F, 1.0F);
      }
   }
}


/*
 * Apply color index shift and offset to an array of pixels.
 */
void
_mesa_shift_and_offset_ci(const struct gl_context *ctx,
                          GLuint n, GLuint indexes[])
{
   GLint shift = ctx->Pixel.IndexShift;
   GLint offset = ctx->Pixel.IndexOffset;
   GLuint i;
   if (shift > 0) {
      for (i=0;i<n;i++) {
         indexes[i] = (indexes[i] << shift) + offset;
      }
   }
   else if (shift < 0) {
      shift = -shift;
      for (i=0;i<n;i++) {
         indexes[i] = (indexes[i] >> shift) + offset;
      }
   }
   else {
      for (i=0;i<n;i++) {
         indexes[i] = indexes[i] + offset;
      }
   }
}


/**
 * Apply color index shift, offset and table lookup to an array
 * of color indexes;
 */
void
_mesa_apply_ci_transfer_ops(const struct gl_context *ctx,
                            GLbitfield transferOps,
                            GLuint n, GLuint indexes[])
{
   if (transferOps & IMAGE_SHIFT_OFFSET_BIT) {
      _mesa_shift_and_offset_ci(ctx, n, indexes);
   }
   if (transferOps & IMAGE_MAP_COLOR_BIT) {
      const GLuint mask = ctx->PixelMaps.ItoI.Size - 1;
      GLuint i;
      for (i = 0; i < n; i++) {
         const GLuint j = indexes[i] & mask;
         indexes[i] = F_TO_I(ctx->PixelMaps.ItoI.Map[j]);
      }
   }
}


/**
 * Apply stencil index shift, offset and table lookup to an array
 * of stencil values.
 */
void
_mesa_apply_stencil_transfer_ops(const struct gl_context *ctx, GLuint n,
                                 GLubyte stencil[])
{
   if (ctx->Pixel.IndexShift != 0 || ctx->Pixel.IndexOffset != 0) {
      const GLint offset = ctx->Pixel.IndexOffset;
      GLint shift = ctx->Pixel.IndexShift;
      GLuint i;
      if (shift > 0) {
         for (i = 0; i < n; i++) {
            stencil[i] = (stencil[i] << shift) + offset;
         }
      }
      else if (shift < 0) {
         shift = -shift;
         for (i = 0; i < n; i++) {
            stencil[i] = (stencil[i] >> shift) + offset;
         }
      }
      else {
         for (i = 0; i < n; i++) {
            stencil[i] = stencil[i] + offset;
         }
      }
   }
   if (ctx->Pixel.MapStencilFlag) {
      GLuint mask = ctx->PixelMaps.StoS.Size - 1;
      GLuint i;
      for (i = 0; i < n; i++) {
         stencil[i] = (GLubyte) ctx->PixelMaps.StoS.Map[ stencil[i] & mask ];
      }
   }
}