mgapixel.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 * Copyright 2000 Compaq Computer Inc. and VA Linux Systems, 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
 * on the rights to use, copy, modify, merge, publish, distribute, sub
 * license, 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 (including the next
 * paragraph) 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 NON-INFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS 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 mgapixel.c
 * Implement framebuffer pixel operations for MGA.
 *
 * \todo
 * Someday the accelerated \c glReadPixels and \c glDrawPixels paths need to
 * be resurrected.  They are currently ifdef'ed out because they don't seem
 * to work and they only get activated some very rare circumstances.
 *
 * \author Keith Whitwell <[e-mail]>
 * \author Gareth Hughes <[e-mail]>
 */
/* $XFree86: xc/lib/GL/mesa/src/drv/mga/mgapixel.c,v 1.9 2002/11/05 17:46:08 tsi Exp $ */

#include "mtypes.h"
#include "macros.h"
#include "mgadd.h"
#include "mgacontext.h"
#include "mgaioctl.h"
#include "mgapixel.h"
#include "mgastate.h"

#include "swrast/swrast.h"
#include "imports.h"

#if 0
#define IS_AGP_MEM( mmesa, p )						  \
   ((unsigned long)mmesa->mgaScreen->buffers.map <= ((unsigned long)p) && \
    (unsigned long)mmesa->mgaScreen->buffers.map +			  \
    (unsigned long)mmesa->mgaScreen->buffers.size > ((unsigned long)p))
#define AGP_OFFSET( mmesa, p )						  \
     (((unsigned long)p) - (unsigned long)mmesa->mgaScreen->buffers.map)


#if defined(MESA_packed_depth_stencil)
static GLboolean
check_depth_stencil_24_8( const GLcontext *ctx, GLenum type,
			  const struct gl_pixelstore_attrib *packing,
			  const void *pixels, GLint sz,
			  GLint pitch )
{
   mgaContextPtr mmesa = MGA_CONTEXT(ctx);

   return ( type == GL_UNSIGNED_INT_24_8_MESA &&
	    ctx->Visual->DepthBits == 24 &&
	    ctx->Visual->StencilBits == 8 &&
	    mmesa->mgaScreen->cpp == 4 &&
	    mmesa->hw_stencil &&
	    !ctx->Pixel.IndexShift &&
	    !ctx->Pixel.IndexOffset &&
	    !ctx->Pixel.MapStencilFlag &&
	    ctx->Pixel.DepthBias == 0.0 &&
	    ctx->Pixel.DepthScale == 1.0 &&
	    !packing->SwapBytes &&
	    pitch % 32 == 0 &&
	    pitch < 4096 );
}
#endif


static GLboolean
check_depth( const GLcontext *ctx, GLenum type,
	     const struct gl_pixelstore_attrib *packing,
	     const void *pixels, GLint sz, GLint pitch )
{
   mgaContextPtr mmesa = MGA_CONTEXT(ctx);

   if ( IS_AGP_MEM( mmesa, pixels ) &&
	!( ( type == GL_UNSIGNED_INT && mmesa->mgaScreen->cpp == 4 ) ||
	   ( type == GL_UNSIGNED_SHORT && mmesa->mgaScreen->cpp == 2 ) ) )
      return GL_FALSE;

   return ( ctx->Pixel.DepthBias == 0.0 &&
	    ctx->Pixel.DepthScale == 1.0 &&
	    !packing->SwapBytes &&
	    pitch % 32 == 0 &&
	    pitch < 4096 );
}


static GLboolean
check_color( const GLcontext *ctx, GLenum type, GLenum format,
	     const struct gl_pixelstore_attrib *packing,
	     const void *pixels, GLint sz, GLint pitch )
{
   mgaContextPtr mmesa = MGA_CONTEXT(ctx);
   GLuint cpp = mmesa->mgaScreen->cpp;

   /* Can't do conversions on agp reads/draws.
    */
   if ( IS_AGP_MEM( mmesa, pixels ) &&
	!( pitch % 32 == 0 && pitch < 4096 &&
	   ( ( type == GL_UNSIGNED_BYTE &&
	       cpp == 4 && format == GL_BGRA ) ||
	     ( type == GL_UNSIGNED_INT_8_8_8_8 &&
	       cpp == 4 && format == GL_BGRA ) ||
	     ( type == GL_UNSIGNED_SHORT_5_6_5_REV &&
	       cpp == 2 && format == GL_RGB ) ) ) )
      return GL_FALSE;

   return (!ctx->_ImageTransferState &&
	   !packing->SwapBytes &&
	   !packing->LsbFirst);
}

static GLboolean
check_color_per_fragment_ops( const GLcontext *ctx )
{
   return (!(       ctx->Color.AlphaEnabled ||
		    ctx->Depth.Test ||
		    ctx->Fog.Enabled ||
		    ctx->Scissor.Enabled ||
		    ctx->Stencil.Enabled ||
		    !ctx->Color.ColorMask[0] ||
		    !ctx->Color.ColorMask[1] ||
		    !ctx->Color.ColorMask[2] ||
		    !ctx->Color.ColorMask[3] ||
		    ctx->Color.ColorLogicOpEnabled ||
		    ctx->Texture._EnabledUnits
           ) &&
	   ctx->Current.RasterPosValid &&
	   ctx->Pixel.ZoomX == 1.0F &&
	   (ctx->Pixel.ZoomY == 1.0F || ctx->Pixel.ZoomY == -1.0F));
}

static GLboolean
check_depth_per_fragment_ops( const GLcontext *ctx )
{
   return ( ctx->Current.RasterPosValid &&
	    ctx->Color.ColorMask[RCOMP] == 0 &&
	    ctx->Color.ColorMask[BCOMP] == 0 &&
	    ctx->Color.ColorMask[GCOMP] == 0 &&
	    ctx->Color.ColorMask[ACOMP] == 0 &&
	    ctx->Pixel.ZoomX == 1.0F &&
	    ( ctx->Pixel.ZoomY == 1.0F || ctx->Pixel.ZoomY == -1.0F ) );
}

/* In addition to the requirements for depth:
 */
#if defined(MESA_packed_depth_stencil)
static GLboolean
check_stencil_per_fragment_ops( const GLcontext *ctx )
{
   return ( !ctx->Pixel.IndexShift &&
	    !ctx->Pixel.IndexOffset );
}
#endif


static GLboolean
clip_pixelrect( const GLcontext *ctx,
		const GLframebuffer *buffer,
		GLint *x, GLint *y,
		GLsizei *width, GLsizei *height,
		GLint *skipPixels, GLint *skipRows,
		GLint *size )
{
   mgaContextPtr mmesa = MGA_CONTEXT(ctx);

   *width = MIN2(*width, MAX_WIDTH); /* redundant? */

   /* left clipping */
   if (*x < buffer->_Xmin) {
      *skipPixels += (buffer->_Xmin - *x);
      *width -= (buffer->_Xmin - *x);
      *x = buffer->_Xmin;
   }

   /* right clipping */
   if (*x + *width > buffer->_Xmax)
      *width -= (*x + *width - buffer->_Xmax - 1);

   if (*width <= 0)
      return GL_FALSE;

   /* bottom clipping */
   if (*y < buffer->_Ymin) {
      *skipRows += (buffer->_Ymin - *y);
      *height -= (buffer->_Ymin - *y);
      *y = buffer->_Ymin;
   }

   /* top clipping */
   if (*y + *height > buffer->_Ymax)
      *height -= (*y + *height - buffer->_Ymax - 1);

   if (*height <= 0)
      return GL_FALSE;

   *size = ((*y + *height - 1) * mmesa->mgaScreen->frontPitch +
	    (*x + *width - 1) * mmesa->mgaScreen->cpp);

   return GL_TRUE;
}

static GLboolean
mgaTryReadPixels( GLcontext *ctx,
		  GLint x, GLint y, GLsizei width, GLsizei height,
		  GLenum format, GLenum type,
		  const struct gl_pixelstore_attrib *pack,
		  GLvoid *pixels )
{
   mgaContextPtr mmesa = MGA_CONTEXT(ctx);
   GLint size, skipPixels, skipRows;
   GLint pitch = pack->RowLength ? pack->RowLength : width;
   GLboolean ok;

   GLuint planemask;
   GLuint source;
#if 0
   drmMGABlit blit;
   GLuint dest;
   GLint source_pitch, dest_pitch;
   GLint delta_sx, delta_sy;
   GLint delta_dx, delta_dy;
   GLint blit_height, ydir;
#endif

   if (!clip_pixelrect(ctx, ctx->ReadBuffer,
		       &x, &y, &width, &height,
		       &skipPixels, &skipRows, &size)) {
      return GL_TRUE;
   }

   /* Only accelerate reading to agp buffers.
    */
   if ( !IS_AGP_MEM(mmesa, (char *)pixels) ||
	!IS_AGP_MEM(mmesa, (char *)pixels + size) )
      return GL_FALSE;

   switch (format) {
#if defined(MESA_packed_depth_stencil)
   case GL_DEPTH_STENCIL_MESA:
      ok = check_depth_stencil_24_8(ctx, type, pack, pixels, size, pitch);
      planemask = ~0;
      source = mmesa->mgaScreen->depthOffset;
      break;
#endif

   case GL_DEPTH_COMPONENT:
      ok = check_depth(ctx, type, pack, pixels, size, pitch);

      /* Can't accelerate at this depth -- planemask does the wrong
       * thing; it doesn't clear the low order bits in the
       * destination, instead it leaves them untouched.
       *
       * Could get the acclerator to solid fill the destination with
       * zeros first...  Or get the cpu to do it...
       */
      if (ctx->Visual.depthBits == 24)
	 return GL_FALSE;

      planemask = ~0;
      source = mmesa->mgaScreen->depthOffset;
      break;

   case GL_RGB:
   case GL_BGRA:
      ok = check_color(ctx, type, format, pack, pixels, size, pitch);
      planemask = ~0;
      source = (mmesa->draw_buffer == MGA_FRONT ?
		mmesa->mgaScreen->frontOffset :
		mmesa->mgaScreen->backOffset);
      break;

   default:
      return GL_FALSE;
   }

   if (!ok) {
      return GL_FALSE;
   }


   LOCK_HARDWARE( mmesa );

#if 0
   {
      __DRIdrawablePrivate *dPriv = mmesa->driDrawable;
      int nbox, retcode, i;

      UPDATE_LOCK( mmesa, DRM_LOCK_FLUSH | DRM_LOCK_QUIESCENT );

      if (mmesa->dirty_cliprects & MGA_FRONT)
	 mgaUpdateRects( mmesa, MGA_FRONT );

      nbox = dPriv->numClipRects;

      y = dPriv->h - y - height;
      x += mmesa->drawX;
      y += mmesa->drawY;

      dest = ((mmesa->mgaScreen->agp.handle + AGP_OFFSET(mmesa, pixels)) |
	      DO_dstmap_sys | DO_dstacc_agp);
      source_pitch = mmesa->mgaScreen->frontPitch / mmesa->mgaScreen->cpp;
      dest_pitch = pitch;
      delta_sx = 0;
      delta_sy = 0;
      delta_dx = -x;
      delta_dy = -y;
      blit_height = 2*y + height;
      ydir = -1;

      if (0) fprintf(stderr, "XX doing readpixel blit src_pitch %d dst_pitch %d\n",
		     source_pitch, dest_pitch);