/**************************************************************************
 * 
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * 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, 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 TUNGSTEN GRAPHICS 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.
 * 
 **************************************************************************/

#include "glheader.h"
#include "enums.h"
#include "mtypes.h"
#include "macros.h"
#include "utils.h"

#include "intel_screen.h"
#include "intel_batchbuffer.h"
#include "intel_ioctl.h"

#include "i830_context.h"
#include "i830_reg.h"

/* A large amount of state doesn't need to be uploaded.
 */
#define ACTIVE (I830_UPLOAD_TEXBLEND(0) |	\
		I830_UPLOAD_STIPPLE |		\
		I830_UPLOAD_CTX |		\
		I830_UPLOAD_BUFFERS |		\
		I830_UPLOAD_TEX(0))		


#define SET_STATE( i830, STATE )		\
do {						\
   i830->current->emitted &= ~ACTIVE;			\
   i830->current = &i830->STATE;		\
   i830->current->emitted &= ~ACTIVE;			\
} while (0)

/* Operations where the 3D engine is decoupled temporarily from the
 * current GL state and used for other purposes than simply rendering
 * incoming triangles.
 */
static void set_initial_state( i830ContextPtr i830 )
{
   memcpy(&i830->meta, &i830->initial, sizeof(i830->meta) );
   i830->meta.active = ACTIVE;
   i830->meta.emitted = 0;
}


static void set_no_depth_stencil_write( i830ContextPtr i830 )
{
   /* ctx->Driver.Enable( ctx, GL_STENCIL_TEST, GL_FALSE )
    */
   i830->meta.Ctx[I830_CTXREG_ENABLES_1] &= ~ENABLE_STENCIL_TEST;
   i830->meta.Ctx[I830_CTXREG_ENABLES_2] &= ~ENABLE_STENCIL_WRITE;
   i830->meta.Ctx[I830_CTXREG_ENABLES_1] |= DISABLE_STENCIL_TEST;
   i830->meta.Ctx[I830_CTXREG_ENABLES_2] |= DISABLE_STENCIL_WRITE;


   /* ctx->Driver.Enable( ctx, GL_DEPTH_TEST, GL_FALSE )
    */
   i830->meta.Ctx[I830_CTXREG_ENABLES_1] &= ~ENABLE_DIS_DEPTH_TEST_MASK;
   i830->meta.Ctx[I830_CTXREG_ENABLES_2] &= ~ENABLE_DIS_DEPTH_WRITE_MASK;
   i830->meta.Ctx[I830_CTXREG_ENABLES_1] |= DISABLE_DEPTH_TEST;
   i830->meta.Ctx[I830_CTXREG_ENABLES_2] |= DISABLE_DEPTH_WRITE;

   i830->meta.emitted &= ~I830_UPLOAD_CTX;
}

/* Set stencil unit to replace always with the reference value.
 */
static void set_stencil_replace( i830ContextPtr i830,
				 GLuint s_mask,
				 GLuint s_clear)
{
   /* ctx->Driver.Enable( ctx, GL_STENCIL_TEST, GL_TRUE )
    */
   i830->meta.Ctx[I830_CTXREG_ENABLES_1] |= ENABLE_STENCIL_TEST;
   i830->meta.Ctx[I830_CTXREG_ENABLES_2] |= ENABLE_STENCIL_WRITE;


   /* ctx->Driver.Enable( ctx, GL_DEPTH_TEST, GL_FALSE )
    */
   i830->meta.Ctx[I830_CTXREG_ENABLES_1] &= ~ENABLE_DIS_DEPTH_TEST_MASK;
   i830->meta.Ctx[I830_CTXREG_ENABLES_2] &= ~ENABLE_DIS_DEPTH_WRITE_MASK;
   i830->meta.Ctx[I830_CTXREG_ENABLES_1] |= DISABLE_DEPTH_TEST;
   i830->meta.Ctx[I830_CTXREG_ENABLES_2] |= DISABLE_DEPTH_WRITE;

   /* ctx->Driver.StencilMask( ctx, s_mask )
    */
   i830->meta.Ctx[I830_CTXREG_STATE4] &= ~MODE4_ENABLE_STENCIL_WRITE_MASK;
   i830->meta.Ctx[I830_CTXREG_STATE4] |= (ENABLE_STENCIL_WRITE_MASK |
					   STENCIL_WRITE_MASK((s_mask&0xff)));

   /* ctx->Driver.StencilOp( ctx, GL_REPLACE, GL_REPLACE, GL_REPLACE )
    */
   i830->meta.Ctx[I830_CTXREG_STENCILTST] &= ~(STENCIL_OPS_MASK);
   i830->meta.Ctx[I830_CTXREG_STENCILTST] |= 
      (ENABLE_STENCIL_PARMS |
       STENCIL_FAIL_OP(STENCILOP_REPLACE) |
       STENCIL_PASS_DEPTH_FAIL_OP(STENCILOP_REPLACE) |
       STENCIL_PASS_DEPTH_PASS_OP(STENCILOP_REPLACE));

   /* ctx->Driver.StencilFunc( ctx, GL_ALWAYS, s_clear, ~0 )
    */
   i830->meta.Ctx[I830_CTXREG_STATE4] &= ~MODE4_ENABLE_STENCIL_TEST_MASK;
   i830->meta.Ctx[I830_CTXREG_STATE4] |= (ENABLE_STENCIL_TEST_MASK |
					   STENCIL_TEST_MASK(0xff));

   i830->meta.Ctx[I830_CTXREG_STENCILTST] &= ~(STENCIL_REF_VALUE_MASK |
						ENABLE_STENCIL_TEST_FUNC_MASK);
   i830->meta.Ctx[I830_CTXREG_STENCILTST] |= 
      (ENABLE_STENCIL_REF_VALUE |
       ENABLE_STENCIL_TEST_FUNC |
       STENCIL_REF_VALUE((s_clear&0xff)) |
       STENCIL_TEST_FUNC(COMPAREFUNC_ALWAYS));



   i830->meta.emitted &= ~I830_UPLOAD_CTX;
}


static void set_color_mask( i830ContextPtr i830, GLboolean state )
{
   const GLuint mask = ((1 << WRITEMASK_RED_SHIFT) |
			(1 << WRITEMASK_GREEN_SHIFT) |
			(1 << WRITEMASK_BLUE_SHIFT) |
			(1 << WRITEMASK_ALPHA_SHIFT));

   if (state) {
      i830->meta.Ctx[I830_CTXREG_ENABLES_2] &= ~mask;
      i830->meta.Ctx[I830_CTXREG_ENABLES_2] |= 
	 (i830->state.Ctx[I830_CTXREG_ENABLES_2] & mask);
   }
   else 
      i830->meta.Ctx[I830_CTXREG_ENABLES_2] |= mask;
      
   i830->meta.emitted &= ~I830_UPLOAD_CTX;
}

/* Installs a one-stage passthrough texture blend pipeline.  Is there
 * more that can be done to turn off texturing?
 */
static void set_no_texture( i830ContextPtr i830 )
{
   static const struct gl_tex_env_combine_state comb = {
      GL_NONE, GL_NONE,
      { GL_TEXTURE, 0, 0, }, { GL_TEXTURE, 0, 0, },
      { GL_SRC_COLOR, 0, 0 }, { GL_SRC_ALPHA, 0, 0 },
      0, 0, 0, 0
   };

   i830->meta.TexBlendWordsUsed[0] =
     i830SetTexEnvCombine( i830, & comb, 0, TEXBLENDARG_TEXEL0,
			   i830->meta.TexBlend[0], NULL);

   i830->meta.TexBlend[0][0] |= TEXOP_LAST_STAGE;
   i830->meta.emitted &= ~I830_UPLOAD_TEXBLEND(0);
}

/* Set up a single element blend stage for 'replace' texturing with no
 * funny ops.
 */
static void enable_texture_blend_replace( i830ContextPtr i830,
					  GLenum format )
{
   static const struct gl_tex_env_combine_state comb = {
      GL_REPLACE, GL_REPLACE,
      { GL_TEXTURE, 0, 0, }, { GL_TEXTURE, 0, 0, },
      { GL_SRC_COLOR, 0, 0 }, { GL_SRC_ALPHA, 0, 0 },
      0, 0, 1, 1
   };

   i830->meta.TexBlendWordsUsed[0] =
     i830SetTexEnvCombine( i830, & comb, 0, TEXBLENDARG_TEXEL0,
			   i830->meta.TexBlend[0], NULL);

   i830->meta.TexBlend[0][0] |= TEXOP_LAST_STAGE;
   i830->meta.emitted &= ~I830_UPLOAD_TEXBLEND(0);

/*    fprintf(stderr, "%s: TexBlendWordsUsed[0]: %d\n",  */
/* 	   __FUNCTION__, i830->meta.TexBlendWordsUsed[0]); */
}



/* Set up an arbitary piece of memory as a rectangular texture
 * (including the front or back buffer).
 */
static void set_tex_rect_source( i830ContextPtr i830,
				 GLuint offset,
				 GLuint width, 
				 GLuint height,
				 GLuint pitch,
				 GLuint textureFormat )
{
   GLint numLevels = 1;
   GLuint *setup = i830->meta.Tex[0];

   pitch *= i830->intel.intelScreen->cpp;

/*    fprintf(stderr, "%s: offset: %x w: %d h: %d pitch %d format %x\n", */
/* 	   __FUNCTION__, offset, width, height, pitch, textureFormat ); */

   setup[I830_TEXREG_TM0LI] = (_3DSTATE_LOAD_STATE_IMMEDIATE_2 | 
			       (LOAD_TEXTURE_MAP0 << 0) | 4);
   setup[I830_TEXREG_TM0S0] = (TM0S0_USE_FENCE | offset);
   setup[I830_TEXREG_TM0S1] = (((height - 1) << TM0S1_HEIGHT_SHIFT) |
			       ((width - 1) << TM0S1_WIDTH_SHIFT) |
			       textureFormat);
   setup[I830_TEXREG_TM0S2] = ((((pitch / 4) - 1) << TM0S2_PITCH_SHIFT));   
   setup[I830_TEXREG_TM0S3] &= ~TM0S3_MAX_MIP_MASK;
   setup[I830_TEXREG_TM0S3] &= ~TM0S3_MIN_MIP_MASK;
   setup[I830_TEXREG_TM0S3] |= ((numLevels - 1)*4) << TM0S3_MIN_MIP_SHIFT;

   setup[I830_TEXREG_MCS] = (_3DSTATE_MAP_COORD_SET_CMD |
			     MAP_UNIT(0) |
			     ENABLE_TEXCOORD_PARAMS |
			     TEXCOORDS_ARE_IN_TEXELUNITS |
			     TEXCOORDTYPE_CARTESIAN |
			     ENABLE_ADDR_V_CNTL |
			     TEXCOORD_ADDR_V_MODE(TEXCOORDMODE_WRAP) |
			     ENABLE_ADDR_U_CNTL |
			     TEXCOORD_ADDR_U_MODE(TEXCOORDMODE_WRAP));

   i830->meta.emitted &= ~I830_UPLOAD_TEX(0);
}


/* Select between front and back draw buffers.
 */
static void set_draw_offset( i830ContextPtr i830,
			     GLuint offset )
{
   i830->meta.Buffer[I830_DESTREG_CBUFADDR2] = offset;
   i830->meta.emitted &= ~I830_UPLOAD_BUFFERS;
}

/* Setup an arbitary draw format, useful for targeting
 * texture or agp memory.
 */
static void set_draw_format( i830ContextPtr i830,
			     GLuint format,
			     GLuint depth_format)
{
   i830->meta.Buffer[I830_DESTREG_DV1] = (DSTORG_HORT_BIAS(0x8) | /* .5 */
					  DSTORG_VERT_BIAS(0x8) | /* .5 */
					  format |
					  DEPTH_IS_Z |
					  depth_format);
}


static void set_vertex_format( i830ContextPtr i830 )
{
   i830->meta.Ctx[I830_CTXREG_VF] =  (_3DSTATE_VFT0_CMD |
				      VFT0_TEX_COUNT(1) |
				      VFT0_DIFFUSE |
				      VFT0_SPEC |
				      VFT0_XYZW);
   i830->meta.Ctx[I830_CTXREG_VF2] = (_3DSTATE_VFT1_CMD |
				      VFT1_TEX0_FMT(TEXCOORDFMT_2D) |
				      VFT1_TEX1_FMT(TEXCOORDFMT_2D) | 
				      VFT1_TEX2_FMT(TEXCOORDFMT_2D) |
				      VFT1_TEX3_FMT(TEXCOORDFMT_2D));
   i830->meta.emitted &= ~I830_UPLOAD_CTX;
}


static void draw_quad(i830ContextPtr i830, 
		      GLfloat x0, GLfloat x1,
		      GLfloat y0, GLfloat y1, 
		      GLubyte red, GLubyte green,
		      GLubyte blue, GLubyte alpha,
		      GLfloat s0, GLfloat s1,
		      GLfloat t0, GLfloat t1 )
{
   GLuint vertex_size = 8;
   GLuint *vb = intelEmitInlinePrimitiveLocked( &i830->intel, 
						PRIM3D_TRIFAN, 
						4*vertex_size,
						vertex_size );
   intelVertex tmp;
   int i;

   
/*    fprintf(stderr, "%s: %f,%f-%f,%f 0x%x%x%x%x %f,%f-%f,%f\n", */
/* 	   __FUNCTION__, */
/* 	   x0,y0,x1,y1,red,green,blue,alpha,s0,t0,s1,t1); */


   /* initial vertex, left bottom */
   tmp.v.x = x0;
   tmp.v.y = y0;
   tmp.v.z = 1.0;
   tmp.v.w = 1.0;
   tmp.v.color.red = red;
   tmp.v.color.green = green;
   tmp.v.color.blue = blue;
   tmp.v.color.alpha = alpha;
   tmp.v.specular.red = 0;
   tmp.v.specular.green = 0;
   tmp.v.specular.blue = 0;
   tmp.v.specular.alpha = 0;
   tmp.v.u0 = s0;
   tmp.v.v0 = t0;
   for (i = 0 ; i < 8 ; i++)
      vb[i] = tmp.ui[i];

   /* right bottom */
   vb += 8;
   tmp.v.x = x1;
   tmp.v.u0 = s1;
   for (i = 0 ; i < 8 ; i++)
      vb[i] = tmp.ui[i];

   /* right top */
   vb += 8;
   tmp.v.y = y1;
   tmp.v.v0 = t1;
   for (i = 0 ; i < 8 ; i++)
      vb[i] = tmp.ui[i];

   /* left top */
   vb += 8;
   tmp.v.x = x0;
   tmp.v.u0 = s0;
   for (i = 0 ; i < 8 ; i++)
      vb[i] = tmp.ui[i];

/*    fprintf(stderr, "%s: DV1: %x\n",  */
/* 	   __FUNCTION__, i830->meta.Buffer[I830_DESTREG_DV1]); */
}

void 
i830ClearWithTris(intelContextPtr intel, GLbitfield mask,
		  GLboolean all,
		  GLint cx, GLint cy, GLint cw, GLint ch)
{
   i830ContextPtr i830 = I830_CONTEXT( intel );
   __DRIdrawablePrivate *dPriv = intel->driDrawable;
   intelScreenPrivate *screen = intel->intelScreen;
   int x0, y0, x1, y1;


   SET_STATE( i830, meta );
   set_initial_state( i830 );
   set_no_texture( i830 );
   set_vertex_format( i830 ); 

   LOCK_HARDWARE(intel);

   if(!all) {
      x0 = cx;
      y0 = cy;
      x1 = x0 + cw;
      y1 = y0 + ch;
   } else {
      x0 = 0;
      y0 = 0;
      x1 = x0 + dPriv->w;
      y1 = y0 + dPriv->h;
   }

   /* Don't do any clipping to screen - these are window coordinates.
    * The active cliprects will be applied as for any other geometry.
    */

   if(mask & BUFFER_BIT_FRONT_LEFT) {
      set_no_depth_stencil_write( i830 );
      set_color_mask( i830, GL_TRUE );
      set_draw_offset( i830, screen->frontOffset );
      draw_quad(i830, x0, x1, y0, y1,
		intel->clear_red, intel->clear_green,
		intel->clear_blue, intel->clear_alpha,
		0, 0, 0, 0);
   }

   if(mask & BUFFER_BIT_BACK_LEFT) {
      set_no_depth_stencil_write( i830 );
      set_color_mask( i830, GL_TRUE );
      set_draw_offset( i830, screen->backOffset );

      draw_quad(i830, x0, x1, y0, y1,
		intel->clear_red, intel->clear_green,
		intel->clear_blue, intel->clear_alpha,
		0, 0, 0, 0);
   }

   if(mask & BUFFER_BIT_STENCIL) {
      set_stencil_replace( i830, 
			   intel->ctx.Stencil.WriteMask[0], 
			   intel->ctx.Stencil.Clear);

      set_color_mask( i830, GL_FALSE );
      set_draw_offset( i830, screen->frontOffset );
      draw_quad( i830, x0, x1, y0, y1, 0, 0, 0, 0, 0, 0, 0, 0 );
   }

   UNLOCK_HARDWARE(intel);

   SET_STATE( i830, state );
}




GLboolean
i830TryTextureReadPixels( GLcontext *ctx,
			  GLint x, GLint y, GLsizei width, GLsizei height,
			  GLenum format, GLenum type,
			  const struct gl_pixelstore_attrib *pack,
			  GLvoid *pixels )
{
   i830ContextPtr i830 = I830_CONTEXT(ctx);
   intelContextPtr intel = INTEL_CONTEXT(ctx);
   intelScreenPrivate *screen = i830->intel.intelScreen;
   GLint pitch = pack->RowLength ? pack->RowLength : width;
   __DRIdrawablePrivate *dPriv = i830->intel.driDrawable;
   int textureFormat;
   GLenum glTextureFormat;
   int src_offset = i830->meta.Buffer[I830_DESTREG_CBUFADDR2];
   int destOffset = intelAgpOffsetFromVirtual( &i830->intel, pixels);
   int destFormat, depthFormat, destPitch;
   drm_clip_rect_t tmp;

   if (INTEL_DEBUG & DEBUG_PIXEL)
      fprintf(stderr, "%s\n", __FUNCTION__);


   if (	ctx->_ImageTransferState ||
	pack->SwapBytes ||
	pack->LsbFirst ||
	!pack->Invert) {
      fprintf(stderr, "%s: check_color failed\n", __FUNCTION__);
      return GL_FALSE;
   }

   switch (screen->fbFormat) {
   case DV_PF_565:
      textureFormat = MAPSURF_16BIT | MT_16BIT_RGB565;
      glTextureFormat = GL_RGB;
      break;
   case DV_PF_555:
      textureFormat = MAPSURF_16BIT | MT_16BIT_ARGB1555;
      glTextureFormat = GL_RGBA;
      break;
   case DV_PF_8888:
      textureFormat = MAPSURF_32BIT | MT_32BIT_ARGB8888;
      glTextureFormat = GL_RGBA;
      break;
   default:
      fprintf(stderr, "%s: textureFormat failed %x\n", __FUNCTION__,
	      screen->fbFormat);
      return GL_FALSE;
   }


   switch (type) {
   case GL_UNSIGNED_SHORT_5_6_5: 
      if (format != GL_RGB) return GL_FALSE;
      destFormat = COLR_BUF_RGB565; 
      depthFormat = DEPTH_FRMT_16_FIXED;
      destPitch = pitch * 2;
      break;
   case GL_UNSIGNED_INT_8_8_8_8_REV: 
      if (format != GL_BGRA) return GL_FALSE;
      destFormat = COLR_BUF_ARGB8888; 
      depthFormat = DEPTH_FRMT_24_FIXED_8_OTHER;
      destPitch = pitch * 4;
      break;
   default:
      fprintf(stderr, "%s: destFormat failed %s\n", __FUNCTION__,
	      _mesa_lookup_enum_by_nr(type));
      return GL_FALSE;
   }

   destFormat |= (0x02<<24);

/*    fprintf(stderr, "type: %s destFormat: %x\n", */
/* 	   _mesa_lookup_enum_by_nr(type), */
/* 	   destFormat); */

   intelFlush( ctx );

   SET_STATE( i830, meta );
   set_initial_state( i830 );
   set_no_depth_stencil_write( i830 );

   LOCK_HARDWARE( intel );
   {
      intelWaitForIdle( intel ); /* required by GL */

      if (!driClipRectToFramebuffer(ctx->ReadBuffer, &x, &y, &width, &height)) {
	 UNLOCK_HARDWARE( intel );
	 SET_STATE(i830, state);
	 fprintf(stderr, "%s: cliprect failed\n", __FUNCTION__);
	 return GL_TRUE;
      }

#if 0
      /* FIXME -- Just emit the correct state
       */
      if (i830SetParam(i830->driFd, I830_SETPARAM_CBUFFER_PITCH, 
		      destPitch) != 0) {
	 UNLOCK_HARDWARE( intel );
	 SET_STATE(i830, state);
	 fprintf(stderr, "%s: setparam failed\n", __FUNCTION__);
	 return GL_FALSE;
      }
#endif


      y = dPriv->h - y - height;
      x += dPriv->x;
      y += dPriv->y;


      /* Set the frontbuffer up as a large rectangular texture.
       */
      set_tex_rect_source( i830, 
			   src_offset, 
			   screen->width, 
			   screen->height, 
			   screen->frontPitch, 
			   textureFormat ); 
   
   
      enable_texture_blend_replace( i830, glTextureFormat ); 


      /* Set the 3d engine to draw into the agp memory
       */

      set_draw_offset( i830, destOffset ); 
      set_draw_format( i830, destFormat, depthFormat );  


      /* Draw a single quad, no cliprects:
       */
      i830->intel.numClipRects = 1;
      i830->intel.pClipRects = &tmp;
      i830->intel.pClipRects[0].x1 = 0;
      i830->intel.pClipRects[0].y1 = 0;
      i830->intel.pClipRects[0].x2 = width;
      i830->intel.pClipRects[0].y2 = height;

      draw_quad( i830, 
		 0, width, 0, height, 
		 0, 255, 0, 0, 
		 x, x+width, y, y+height );

      intelWindowMoved( intel );
   }
   UNLOCK_HARDWARE( intel );
   intelFinish( ctx ); /* required by GL */

   SET_STATE( i830, state );
   return GL_TRUE;
}


GLboolean
i830TryTextureDrawPixels( GLcontext *ctx,
			  GLint x, GLint y, GLsizei width, GLsizei height,
			  GLenum format, GLenum type,
			  const struct gl_pixelstore_attrib *unpack,
			  const GLvoid *pixels )
{
   intelContextPtr intel = INTEL_CONTEXT(ctx);
   i830ContextPtr i830 = I830_CONTEXT(ctx);
   GLint pitch = unpack->RowLength ? unpack->RowLength : width;
   __DRIdrawablePrivate *dPriv = intel->driDrawable;
   int textureFormat;
   GLenum glTextureFormat;
   int dst_offset = i830->meta.Buffer[I830_DESTREG_CBUFADDR2];
   int src_offset = intelAgpOffsetFromVirtual( intel, pixels );

   if (INTEL_DEBUG & DEBUG_PIXEL)
      fprintf(stderr, "%s\n", __FUNCTION__);

   /* Todo -- upload images that aren't in agp space, then texture
    * from them.  
    */

   if ( !intelIsAgpMemory( intel, pixels, pitch*height ) ) {
      fprintf(stderr, "%s: intelIsAgpMemory failed\n", __FUNCTION__);
      return GL_FALSE;
   }

   /* Todo -- don't want to clobber all the drawing state like we do
    * for readpixels -- most of this state can be handled just fine.
    */
   if (	ctx->_ImageTransferState ||
	unpack->SwapBytes ||
	unpack->LsbFirst ||
	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->Depth.OcclusionTest) {
      fprintf(stderr, "%s: other tests failed\n", __FUNCTION__);
      return GL_FALSE;
   }

   /* Todo -- remove these restrictions:
    */
   if (ctx->Pixel.ZoomX != 1.0F ||
       ctx->Pixel.ZoomY != -1.0F)
      return GL_FALSE;



   switch (type) {
   case GL_UNSIGNED_SHORT_1_5_5_5_REV:
      if (format != GL_BGRA) return GL_FALSE;
      textureFormat = MAPSURF_16BIT | MT_16BIT_ARGB1555;
      glTextureFormat = GL_RGBA;
      break;
   case GL_UNSIGNED_SHORT_5_6_5: 
      if (format != GL_RGB) return GL_FALSE;
      textureFormat = MAPSURF_16BIT | MT_16BIT_RGB565;
      glTextureFormat = GL_RGB;
      break;
   case GL_UNSIGNED_SHORT_8_8_MESA: 
      if (format != GL_YCBCR_MESA) return GL_FALSE;
      textureFormat = (MAPSURF_422 | MT_422_YCRCB_SWAPY 
/*  		       | TM0S1_COLORSPACE_CONVERSION */
	 );
      glTextureFormat = GL_YCBCR_MESA;
      break;
   case GL_UNSIGNED_SHORT_8_8_REV_MESA: 
      if (format != GL_YCBCR_MESA) return GL_FALSE;
      textureFormat = (MAPSURF_422 | MT_422_YCRCB_NORMAL 
/* 		       | TM0S1_COLORSPACE_CONVERSION */
	 );
      glTextureFormat = GL_YCBCR_MESA;
      break;
   case GL_UNSIGNED_INT_8_8_8_8_REV: 
      if (format != GL_BGRA) return GL_FALSE;
      textureFormat = MAPSURF_32BIT | MT_32BIT_ARGB8888;
      glTextureFormat = GL_RGBA;
      break;
   default:
      fprintf(stderr, "%s: destFormat failed\n", __FUNCTION__);
      return GL_FALSE;
   }

   intelFlush( ctx );

   SET_STATE( i830, meta );

   LOCK_HARDWARE( intel );
   {
      intelWaitForIdle( intel ); /* required by GL */

      y -= height;			/* cope with pixel zoom */

      if (!driClipRectToFramebuffer(ctx->ReadBuffer, &x, &y, &width, &height)) {
	 UNLOCK_HARDWARE( intel );
	 SET_STATE(i830, state);
	 fprintf(stderr, "%s: cliprect failed\n", __FUNCTION__);
	 return GL_TRUE;
      }


      y = dPriv->h - y - height;

      set_initial_state( i830 );

      /* Set the pixel image up as a rectangular texture.
       */
      set_tex_rect_source( i830, 
			   src_offset, 
			   width, 
			   height, 
			   pitch, /* XXXX!!!! -- /2 sometimes */
			   textureFormat ); 
   
   
      enable_texture_blend_replace( i830, glTextureFormat ); 

   
      /* Draw to the current draw buffer:
       */
      set_draw_offset( i830, dst_offset );

      /* Draw a quad, use regular cliprects
       */
/*       fprintf(stderr, "x: %d y: %d width %d height %d\n", x, y, width, height); */

      draw_quad( i830, 
		 x, x+width, y, y+height,
		 0, 255, 0, 0, 
		 0, width, 0, height );

      intelWindowMoved( intel );
   }
   UNLOCK_HARDWARE( intel );
   intelFinish( ctx ); /* required by GL */
   
   SET_STATE(i830, state);

   return GL_TRUE;
}

