/* -*- mode: C; tab-width:8; c-basic-offset:2 -*- */

/*
 * 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.
 *
 *
 * Original Mesa / 3Dfx device driver (C) 1999 David Bucciarelli, by the
 * terms stated above.
 *
 * Thank you for your contribution, David!
 *
 * Please make note of the above copyright/license statement.  If you
 * contributed code or bug fixes to this code under the previous (GNU
 * Library) license and object to the new license, your code will be
 * removed at your request.  Please see the Mesa docs/COPYRIGHT file
 * for more information.
 *
 * Additional Mesa/3Dfx driver developers:
 *   Daryll Strauss <daryll@precisioninsight.com>
 *   Keith Whitwell <keith@precisioninsight.com>
 *
 * See fxapi.h for more revision/author details.
 */


/* fxdd.c - 3Dfx VooDoo Mesa span and pixel functions */


#ifdef HAVE_CONFIG_H
#include "conf.h"
#endif

#if defined(FX)

#include "fxdrv.h"

#ifdef _MSC_VER
#ifdef _WIN32
#pragma warning( disable : 4090 4022 )
/* 4101 : "different 'const' qualifier"
 * 4022 : "pointer mistmatch for actual parameter 'n'
 */
#endif
#endif


#if !defined(FXMESA_USE_ARGB) 

/* KW: Rearranged the args in the call to grLfbWriteRegion().
 */
#define LFB_WRITE_SPAN_MESA(dst_buffer,		\
			    dst_x,		\
			    dst_y,		\
			    src_width,		\
			    src_stride,		\
			    src_data)		\
  writeRegionClipped(fxMesa, dst_buffer,	\
		   dst_x,			\
		   dst_y,			\
		   GR_LFB_SRC_FMT_8888,		\
		   src_width,			\
		   1,				\
		   src_stride,			\
		   src_data)			\


#else /* defined(FXMESA_USE_RGBA) */

#define MESACOLOR_TO_ARGB(c) (				\
             ( ((unsigned int)(c[ACOMP]))<<24 ) |	\
             ( ((unsigned int)(c[RCOMP]))<<16 ) |	\
             ( ((unsigned int)(c[GCOMP]))<<8 )  |	\
             (  (unsigned int)(c[BCOMP])) )
  
void LFB_WRITE_SPAN_MESA(GrBuffer_t dst_buffer, 
			 FxU32 dst_x, 
			 FxU32 dst_y, 
			 FxU32 src_width,
			 FxI32 src_stride, 
			 void *src_data )
{
   /* Covert to ARGB */
   GLubyte (*rgba)[4] = src_data;
   GLuint argb[MAX_WIDTH];
   int i;
   
   for (i = 0; i < src_width; i++)
   {
      argb[i] = MESACOLOR_TO_ARGB(rgba[i]);
   }
   writeRegionClipped(fxMesa, dst_buffer,
		       dst_x,
		       dst_y,
		       GR_LFB_SRC_FMT_8888,
		       src_width,
		       1,
		       src_stride,
		       (void*)argb);
}

#endif

#if defined(FX_GLIDE3) && defined(XF86DRI)

FxBool writeRegionClipped(fxMesaContext fxMesa, GrBuffer_t dst_buffer,
			  FxU32 dst_x, FxU32 dst_y, GrLfbSrcFmt_t src_format,
			  FxU32 src_width, FxU32 src_height, FxI32 src_stride,
			  void *src_data)
{
  int i, x, w;
  void *data;

  if (src_width==1 && src_height==1) { /* Easy case writing a point */
    for (i=0; i<fxMesa->numClipRects; i++) {
      if ((dst_x>=fxMesa->pClipRects[i].x1) && 
	  (dst_x<fxMesa->pClipRects[i].x2) &&
	  (dst_y>=fxMesa->pClipRects[i].y1) && 
	  (dst_y<fxMesa->pClipRects[i].y2)) {
	FX_grLfbWriteRegion(dst_buffer, dst_x, dst_y, src_format,
			    src_width, src_height, src_stride, src_data);
	return GL_TRUE;
      }
    }
  } else if (src_height==1) { /* Writing a span */
    for (i=0; i<fxMesa->numClipRects; i++) {
      if (dst_y>=fxMesa->pClipRects[i].y1 && dst_y<fxMesa->pClipRects[i].y2) {
	if (dst_x<fxMesa->pClipRects[i].x1) {
	  x=fxMesa->pClipRects[i].x1;
	  data=((char*)src_data)+2*(dst_x-x);
	  w=src_width-(x-dst_x);
	} else {
	  x=dst_x;
	  data=src_data;
	  w=src_width;
	}
	if (x+w>fxMesa->pClipRects[i].x2) {
	  w=fxMesa->pClipRects[i].x2-x;
	}
	FX_grLfbWriteRegion(dst_buffer, x, dst_y, src_format, w, src_height,
			    src_stride, data);
      }
    }
  } else { /* Punt on the case of arbitrary rectangles */
    return GL_FALSE;
  }
  return GL_TRUE;
}

#else

#define writeRegionClipped(fxm,dst_buffer,dst_x,dst_y,src_format,src_width,src_height,src_stride,src_data)		\
  FX_grLfbWriteRegion(dst_buffer,dst_x,dst_y,src_format,src_width,src_height,src_stride,src_data)

#endif

/************************************************************************/
/*****                    Span functions                            *****/
/************************************************************************/


static void fxDDWriteRGBASpan(const GLcontext *ctx, 
                              GLuint n, GLint x, GLint y,
                              const GLubyte rgba[][4], const GLubyte mask[])
{
  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
  GLuint i;
  GLint bottom=fxMesa->height+fxMesa->y_offset-1; 

  if (MESA_VERBOSE&VERBOSE_DRIVER) {
     fprintf(stderr,"fxmesa: fxDDWriteRGBASpan(...)\n");
  }

  x+=fxMesa->x_offset;
  if (mask) {
    int span=0;

    for (i=0;i<n;i++) {
      if (mask[i]) {
        ++span; 
      } else {
        if (span > 0) {
          LFB_WRITE_SPAN_MESA( fxMesa->currentFB, x+i-span, bottom-y,
                           /* GR_LFB_SRC_FMT_8888,*/ span, /*1,*/ 0, (void *) rgba[i-span] );
          span = 0;
        }
      }
    }

    if (span > 0)
      LFB_WRITE_SPAN_MESA( fxMesa->currentFB, x+n-span, bottom-y,
                        /* GR_LFB_SRC_FMT_8888, */ span, /*1,*/ 0, (void *) rgba[n-span] );
  } else
    LFB_WRITE_SPAN_MESA( fxMesa->currentFB, x, bottom-y,/* GR_LFB_SRC_FMT_8888,*/
                      n,/* 1,*/ 0, (void *) rgba );
}


static void fxDDWriteRGBSpan(const GLcontext *ctx, 
                             GLuint n, GLint x, GLint y,
                             const GLubyte rgb[][3], const GLubyte mask[])
{
  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
  GLuint i;
  GLint bottom=fxMesa->height+fxMesa->y_offset-1;
  GLubyte rgba[MAX_WIDTH][4];

  if (MESA_VERBOSE&VERBOSE_DRIVER) {
     fprintf(stderr,"fxmesa: fxDDWriteRGBSpan()\n");
  }

  x+=fxMesa->x_offset;
  if (mask) {
    int span=0;

    for (i=0;i<n;i++) {
      if (mask[i]) {
        rgba[span][RCOMP] = rgb[i][0];
        rgba[span][GCOMP] = rgb[i][1];
        rgba[span][BCOMP] = rgb[i][2];
        rgba[span][ACOMP] = 255;
        ++span;
      } else {
        if (span > 0) {
          LFB_WRITE_SPAN_MESA( fxMesa->currentFB, x+i-span, bottom-y,
                            /*GR_LFB_SRC_FMT_8888,*/ span,/* 1,*/ 0, (void *) rgba );
          span = 0;
        }
      }
    }

    if (span > 0)
      LFB_WRITE_SPAN_MESA( fxMesa->currentFB, x+n-span, bottom-y,
                        /*GR_LFB_SRC_FMT_8888,*/ span,/* 1,*/ 0, (void *) rgba );
  } else {
    for (i=0;i<n;i++) {
      rgba[i][RCOMP]=rgb[i][0];
      rgba[i][GCOMP]=rgb[i][1];
      rgba[i][BCOMP]=rgb[i][2];
      rgba[i][ACOMP]=255;
    }

    LFB_WRITE_SPAN_MESA( fxMesa->currentFB, x, bottom-y,/* GR_LFB_SRC_FMT_8888,*/
                      n,/* 1,*/ 0, (void *) rgba );
  }
}


static void fxDDWriteMonoRGBASpan(const GLcontext *ctx, 
                                  GLuint n, GLint x, GLint y,
                                  const GLubyte mask[])
{
  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
  GLuint i;
  GLint bottom=fxMesa->height+fxMesa->y_offset-1;
  GLuint data[MAX_WIDTH];

  if (MESA_VERBOSE&VERBOSE_DRIVER) {
     fprintf(stderr,"fxmesa: fxDDWriteMonoRGBASpan(...)\n");
  }

  x+=fxMesa->x_offset;
  if (mask) {
    int span=0;

    for (i=0;i<n;i++) {
      if (mask[i]) {
        data[span] = (GLuint) fxMesa->color;
        ++span;
      } else {
        if (span > 0) {
          writeRegionClipped(fxMesa,  fxMesa->currentFB, x+i-span, bottom-y,
                            GR_LFB_SRC_FMT_8888, span, 1, 0,
                            (void *) data );
          span = 0;
        }
      }
    }

    if (span > 0)
      writeRegionClipped(fxMesa,  fxMesa->currentFB, x+n-span, bottom-y,
                        GR_LFB_SRC_FMT_8888, span, 1, 0,
                        (void *) data );
  } else {
    for (i=0;i<n;i++) {
      data[i]=(GLuint) fxMesa->color;
    }

    writeRegionClipped(fxMesa,  fxMesa->currentFB, x, bottom-y, GR_LFB_SRC_FMT_8888,
                      n, 1, 0, (void *) data );
  }
}


static void fxDDReadRGBASpan(const GLcontext *ctx, 
                             GLuint n, GLint x, GLint y, GLubyte rgba[][4])
{
  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
  GLushort data[MAX_WIDTH];
  GLuint i;
  GLint bottom=fxMesa->height+fxMesa->y_offset-1;

  if (MESA_VERBOSE&VERBOSE_DRIVER) {
     fprintf(stderr,"fxmesa: fxDDReadRGBASpan(...)\n");
  }

  assert(n < MAX_WIDTH);

  x+=fxMesa->x_offset;
  FX_grLfbReadRegion( fxMesa->currentFB, x, bottom-y, n, 1, 0, data);

  for (i=0;i<n;i++) {
    GLushort pixel = data[i];
    rgba[i][RCOMP] = FX_PixelToR[pixel];
    rgba[i][GCOMP] = FX_PixelToG[pixel];
    rgba[i][BCOMP] = FX_PixelToB[pixel];
    rgba[i][ACOMP] = 255;
  }
}

/************************************************************************/
/*****                    Pixel functions                           *****/
/************************************************************************/

static void fxDDWriteRGBAPixels(const GLcontext *ctx,
                                GLuint n, const GLint x[], const GLint y[],
                                CONST GLubyte rgba[][4], const GLubyte mask[])
{
  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
  GLuint i;
  GLint bottom=fxMesa->height+fxMesa->y_offset-1;

  if (MESA_VERBOSE&VERBOSE_DRIVER) {
     fprintf(stderr,"fxmesa: fxDDWriteRGBAPixels(...)\n");
  }

  for(i=0;i<n;i++)
    if(mask[i])
       LFB_WRITE_SPAN_MESA(fxMesa->currentFB, x[i]+fxMesa->x_offset, bottom-y[i],
                       1, 1, (void *)rgba[i]);
}

static void fxDDWriteMonoRGBAPixels(const GLcontext *ctx,
                                    GLuint n, const GLint x[], const GLint y[],
                                    const GLubyte mask[])
{
  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
  GLuint i;
  GLint bottom=fxMesa->height+fxMesa->y_offset-1;

  if (MESA_VERBOSE&VERBOSE_DRIVER) {
     fprintf(stderr,"fxmesa: fxDDWriteMonoRGBAPixels(...)\n");
  }

  for(i=0;i<n;i++)
    if(mask[i])
      writeRegionClipped(fxMesa, fxMesa->currentFB,x[i]+fxMesa->x_offset,bottom-y[i],
                       GR_LFB_SRC_FMT_8888,1,1,0,(void *) &fxMesa->color);
}

static void fxDDReadRGBAPixels(const GLcontext *ctx,
                               GLuint n, const GLint x[], const GLint y[],
                               GLubyte rgba[][4], const GLubyte mask[])
{
  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
  GLuint i;
  GLint bottom=fxMesa->y_delta-1;

  if (MESA_VERBOSE&VERBOSE_DRIVER) {
     fprintf(stderr,"fxmesa: fxDDReadRGBAPixels(...)\n");
  }

  for(i=0;i<n;i++) {
    if(mask[i]) {
      GLushort pixel;
      FX_grLfbReadRegion(fxMesa->currentFB,x[i],bottom-y[i],1,1,0,&pixel);
      rgba[i][RCOMP] = FX_PixelToR[pixel];
      rgba[i][GCOMP] = FX_PixelToG[pixel];
      rgba[i][BCOMP] = FX_PixelToB[pixel];
      rgba[i][ACOMP] = 255;
    }
  }
}


/************************************************************************/
/*****                    Depth functions                           *****/
/************************************************************************/

void fxDDReadDepthSpanFloat(GLcontext *ctx,
			    GLuint n, GLint x, GLint y, GLfloat depth[])
{
  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
  GLuint i;
  GLint bottom=fxMesa->height+fxMesa->y_offset-1;
  GLushort data[MAX_WIDTH];

  if (MESA_VERBOSE&VERBOSE_DRIVER) {
     fprintf(stderr,"fxmesa: fxDDReadDepthSpanFloat(...)\n");
  }

  x+=fxMesa->x_offset;
  FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x,bottom-y,n,1,0,data);

  /*
    convert the read values to float values [0.0 .. 1.0].
  */
  for(i=0;i<n;i++)
    depth[i]=data[i]/65535.0f;
}

void fxDDReadDepthSpanInt(GLcontext *ctx,
			  GLuint n, GLint x, GLint y, GLdepth depth[])
{
  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
  GLint bottom=fxMesa->height+fxMesa->y_offset-1;

  if (MESA_VERBOSE&VERBOSE_DRIVER) {
     fprintf(stderr,"fxmesa: fxDDReadDepthSpanInt(...)\n");
  }

  x+=fxMesa->x_offset;
  FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x,bottom-y,n,1,0,depth);
}

GLuint fxDDDepthTestSpanGeneric(GLcontext *ctx,
                                       GLuint n, GLint x, GLint y, const GLdepth z[],
                                       GLubyte mask[])
{
  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
  GLushort depthdata[MAX_WIDTH];
  GLdepth *zptr=depthdata;
  GLubyte *m=mask;
  GLuint i;
  GLuint passed=0;
  GLint bottom=fxMesa->height+fxMesa->y_offset-1;

  if (MESA_VERBOSE&VERBOSE_DRIVER) {
     fprintf(stderr,"fxmesa: fxDDDepthTestSpanGeneric(...)\n");
  }

  x+=fxMesa->x_offset;
  FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x,bottom-y,n,1,0,depthdata);

  /* switch cases ordered from most frequent to less frequent */
  switch (ctx->Depth.Func) {
  case GL_LESS:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0; i<n; i++,zptr++,m++) {
        if (*m) {
          if (z[i] < *zptr) {
            /* pass */
            *zptr = z[i];
            passed++;
          } else {
            /* fail */
            *m = 0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0; i<n; i++,zptr++,m++) {
        if (*m) {
          if (z[i] < *zptr) {
            /* pass */
            passed++;
          } else {
            *m = 0;
          }
        }
      }
    }
    break;
  case GL_LEQUAL:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0;i<n;i++,zptr++,m++) {
        if (*m) {
          if (z[i] <= *zptr) {
            *zptr = z[i];
            passed++;
          } else {
            *m = 0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0;i<n;i++,zptr++,m++) {
        if (*m) {
          if (z[i] <= *zptr) {
            /* pass */
            passed++;
          } else {
            *m = 0;
          }
        }
      }
    }
    break;
  case GL_GEQUAL:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0;i<n;i++,zptr++,m++) {
        if (*m) {
          if (z[i] >= *zptr) {
            *zptr = z[i];
            passed++;
          } else {
            *m = 0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0;i<n;i++,zptr++,m++) {
        if (*m) {
          if (z[i] >= *zptr) {
            /* pass */
            passed++;
          } else {
            *m = 0;
          }
        }
      }
    }
    break;
  case GL_GREATER:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0;i<n;i++,zptr++,m++) {
        if (*m) {
          if (z[i] > *zptr) {
            *zptr = z[i];
            passed++;
          } else {
            *m = 0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0;i<n;i++,zptr++,m++) {
        if (*m) {
          if (z[i] > *zptr) {
            /* pass */
            passed++;
          } else {
            *m = 0;
          }
        }
      }
    }
    break;
  case GL_NOTEQUAL:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0;i<n;i++,zptr++,m++) {
        if (*m) {
          if (z[i] != *zptr) {
            *zptr = z[i];
            passed++;
          } else {
            *m = 0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0;i<n;i++,zptr++,m++) {
        if (*m) {
          if (z[i] != *zptr) {
            /* pass */
            passed++;
          } else {
            *m = 0;
          }
        }
      }
    }
    break;
  case GL_EQUAL:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0;i<n;i++,zptr++,m++) {
        if (*m) {
          if (z[i] == *zptr) {
            *zptr = z[i];
            passed++;
          } else {
            *m =0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0;i<n;i++,zptr++,m++) {
        if (*m) {
          if (z[i] == *zptr) {
            /* pass */
            passed++;
          } else {
            *m =0;
          }
        }
      }
    }
    break;
  case GL_ALWAYS:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0;i<n;i++,zptr++,m++) {
        if (*m) {
          *zptr = z[i];
          passed++;
        }
      }
    } else {
      /* Don't update Z buffer or mask */
      passed = n;
    }
    break;
  case GL_NEVER:
    for (i=0;i<n;i++) {
      mask[i] = 0;
    }
    break;
  default:
    ;
  } /*switch*/

  if(passed)
    writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER,x,bottom-y,GR_LFB_SRC_FMT_ZA16,n,1,0,depthdata);

  return passed;
}

void fxDDDepthTestPixelsGeneric(GLcontext* ctx,
                                       GLuint n, const GLint x[], const GLint y[],
                                       const GLdepth z[], GLubyte mask[])
{
  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
  GLdepth zval;
  GLuint i;
  GLint bottom=fxMesa->height+fxMesa->y_offset-1;

  if (MESA_VERBOSE&VERBOSE_DRIVER) {
     fprintf(stderr,"fxmesa: fxDDDepthTestPixelsGeneric(...)\n");
  }

  /* switch cases ordered from most frequent to less frequent */
  switch (ctx->Depth.Func) {
  case GL_LESS:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] < zval) {
            /* pass */
            writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],GR_LFB_SRC_FMT_ZA16,1,1,0,(void*)&z[i]);
          } else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] < zval) {
            /* pass */
          }
          else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    }
    break;
  case GL_LEQUAL:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] <= zval) {
            /* pass */
            writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],GR_LFB_SRC_FMT_ZA16,1,1,0,(void*)&z[i]);
          } else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] <= zval) {
            /* pass */
          } else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    }
    break;
  case GL_GEQUAL:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] >= zval) {
            /* pass */
            writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],GR_LFB_SRC_FMT_ZA16,1,1,0,(void*)&z[i]);
          } else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] >= zval) {
            /* pass */
          } else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    }
    break;
  case GL_GREATER:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] > zval) {
            /* pass */
            writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],GR_LFB_SRC_FMT_ZA16,1,1,0,(void*)&z[i]);
          } else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] > zval) {
            /* pass */
          } else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    }
    break;
  case GL_NOTEQUAL:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] != zval) {
            /* pass */
            writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],GR_LFB_SRC_FMT_ZA16,1,1,0,(void*)&z[i]);
          } else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] != zval) {
            /* pass */
          }
          else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    }
    break;
  case GL_EQUAL:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] == zval) {
            /* pass */
            writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],GR_LFB_SRC_FMT_ZA16,1,1,0,(void*)&z[i]);
          } else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    } else {
      /* Don't update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],1,1,0,&zval);
          if (z[i] == zval) {
            /* pass */
          } else {
            /* fail */
            mask[i] = 0;
          }
        }
      }
    }
    break;
  case GL_ALWAYS:
    if (ctx->Depth.Mask) {
      /* Update Z buffer */
      for (i=0; i<n; i++) {
        if (mask[i]) {
          writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER,x[i]+fxMesa->x_offset,bottom-y[i],GR_LFB_SRC_FMT_ZA16,1,1,0,(void*)&z[i]);
        }
      }
    } else {
      /* Don't update Z buffer or mask */
    }
    break;
  case GL_NEVER:
    /* depth test never passes */
    for (i=0;i<n;i++) {
      mask[i] = 0;
    }
    break;
  default:
    ;
  } /*switch*/
}

/************************************************************************/


void fxSetupDDSpanPointers(GLcontext *ctx)
{
  ctx->Driver.WriteRGBASpan       =fxDDWriteRGBASpan;
  ctx->Driver.WriteRGBSpan        =fxDDWriteRGBSpan;
  ctx->Driver.WriteMonoRGBASpan   =fxDDWriteMonoRGBASpan;
  ctx->Driver.WriteRGBAPixels     =fxDDWriteRGBAPixels;
  ctx->Driver.WriteMonoRGBAPixels =fxDDWriteMonoRGBAPixels;

  ctx->Driver.WriteCI8Span        =NULL;
  ctx->Driver.WriteCI32Span       =NULL;
  ctx->Driver.WriteMonoCISpan     =NULL;
  ctx->Driver.WriteCI32Pixels     =NULL;
  ctx->Driver.WriteMonoCIPixels   =NULL;

  ctx->Driver.ReadRGBASpan        =fxDDReadRGBASpan;
  ctx->Driver.ReadRGBAPixels      =fxDDReadRGBAPixels;

  ctx->Driver.ReadCI32Span        =NULL;
  ctx->Driver.ReadCI32Pixels      =NULL;
}


#else


/*
 * Need this to provide at least one external definition.
 */

int gl_fx_dummy_function_span(void)
{
  return 0;
}

#endif  /* FX */