src/mesa/drivers/dri/s3v/s3v_span.c - fp2-dev/platform/external/mesa3d - Gitiles

 /*
  * Author: Max Lingua <sunmax@libero.it>
  */

 #include "s3v_context.h"
 #include "s3v_lock.h"

 #include "swrast/swrast.h"

 #define _SPANLOCK 1
 #define DBG 0

 #define LOCAL_VARS \
 	s3vContextPtr vmesa = S3V_CONTEXT(ctx);	\
 	s3vScreenPtr s3vscrn = vmesa->s3vScreen; \
 	__DRIscreenPrivate *sPriv = vmesa->driScreen; \
 	__DRIdrawablePrivate *dPriv = vmesa->driDrawable; \
 	GLuint pitch = ( (vmesa->Flags & S3V_BACK_BUFFER) ? \
 			((dPriv->w+31)&~31) * s3vscrn->cpp \
 			: sPriv->fbWidth * s3vscrn->cpp); \
 	GLuint height = dPriv->h; \
 	char *buf = ( (vmesa->Flags & S3V_BACK_BUFFER) ? \
 			(char *)(sPriv->pFB + vmesa->drawOffset) \
 			: (char *)(sPriv->pFB + vmesa->drawOffset \
 			  + dPriv->x * s3vscrn->cpp + dPriv->y * pitch) ); \
 	char *read_buf = ( (vmesa->Flags & S3V_BACK_BUFFER) ? \
 			(char *)(sPriv->pFB + vmesa->drawOffset) \
 			: (char *)(sPriv->pFB + vmesa->drawOffset \
 		          + dPriv->x * s3vscrn->cpp + dPriv->y * pitch) ); \
 	GLuint p; \
 	(void) read_buf; (void) buf; (void) p; (void) pitch

 /* FIXME! Depth/Stencil read/writes don't work ! */
 #define LOCAL_DEPTH_VARS \
 	s3vScreenPtr s3vscrn = vmesa->s3vScreen; \
 	__DRIdrawablePrivate *dPriv = vmesa->driDrawable; \
 	__DRIscreenPrivate *sPriv = vmesa->driScreen; \
 	GLuint pitch = s3vscrn->depthPitch; \
 	GLuint height = dPriv->h; \
 	char *buf = (char *)(sPriv->pFB + \
 			s3vscrn->depthOffset); /* + \
 			dPriv->x * s3vscrn->cpp + \
 			dPriv->y * pitch)*/ \
 	(void) pitch

 #define LOCAL_STENCIL_VARS	LOCAL_DEPTH_VARS


 #define CLIPPIXEL( _x, _y ) \
 	((_x >= minx) && (_x < maxx) && (_y >= miny) && (_y < maxy))


 #define CLIPSPAN( _x, _y, _n, _x1, _n1, _i ) \
 	if ( _y < miny || _y >= maxy ) { \
 		_n1 = 0, _x1 = x; \
 	} else { \
 		_n1 = _n; \
 		_x1 = _x; \
 		if ( _x1 < minx ) \
 			_i += (minx-_x1), n1 -= (minx-_x1), _x1 = minx; \
       		if ( _x1 + _n1 >= maxx ) \
 			n1 -= (_x1 + n1 - maxx); \
 	}

 #define Y_FLIP( _y )	(height - _y - 1)

 #if _SPANLOCK	/* OK, we lock */

 #define HW_LOCK() \
 	s3vContextPtr vmesa = S3V_CONTEXT(ctx);	\
 	(void) vmesa; \
 	DMAFLUSH(); \
 	S3V_SIMPLE_FLUSH_LOCK(vmesa);
 #define HW_UNLOCK() S3V_SIMPLE_UNLOCK(vmesa);

 #else			/* plz, don't lock */

 #define HW_LOCK() \
 	s3vContextPtr vmesa = S3V_CONTEXT(ctx); \
     (void) vmesa; \
 	DMAFLUSH();
 #define HW_UNLOCK()

 #endif

 #define HW_CLIPLOOP()							\
    do {									\
       __DRIdrawablePrivate *dPriv = vmesa->driDrawable;			\
       int _nc = dPriv->numClipRects;					\
 									\
       while ( _nc-- ) {							\
 	 int minx = dPriv->pClipRects[_nc].x1 - dPriv->x;		\
 	 int miny = dPriv->pClipRects[_nc].y1 - dPriv->y;		\
 	 int maxx = dPriv->pClipRects[_nc].x2 - dPriv->x;		\
 	 int maxy = dPriv->pClipRects[_nc].y2 - dPriv->y;

 #define HW_ENDCLIPLOOP()						\
       }									\
    } while (0)


 /* ================================================================
  * Color buffer
  */

 /* 16 bit, RGB565 color spanline and pixel functions
  */
 #define INIT_MONO_PIXEL(p, color) \
   p = S3VIRGEPACKCOLOR555( color[0], color[1], color[2], color[3] )

 #define WRITE_RGBA( _x, _y, r, g, b, a ) \
 do { \
    *(GLushort *)(buf + _x*2 + _y*pitch) = ((((int)r & 0xf8) << 7) | \
 					   (((int)g & 0xf8) << 2) | \
 					   (((int)b & 0xf8) >> 3)); \
    DEBUG(("buf=0x%x drawOffset=0x%x dPriv->x=%i s3vscrn->cpp=%i dPriv->y=%i pitch=%i\n", \
    	sPriv->pFB, vmesa->drawOffset, dPriv->x, s3vscrn->cpp, dPriv->y, pitch)); \
    DEBUG(("dPriv->w = %i\n", dPriv->w)); \
 } while(0)

 #define WRITE_PIXEL( _x, _y, p ) \
    *(GLushort *)(buf + _x*2 + _y*pitch) = p

 #define READ_RGBA( rgba, _x, _y ) \
    do { \
       GLushort p = *(GLushort *)(read_buf + _x*2 + _y*pitch); \
       rgba[0] = (p >> 7) & 0xf8; \
       rgba[1] = (p >> 2) & 0xf8; \
       rgba[2] = (p << 3) & 0xf8; \
       rgba[3] = 0xff; /*
       if ( rgba[0] & 0x08 ) rgba[0] |= 0x07; \
       if ( rgba[1] & 0x04 ) rgba[1] |= 0x03; \
       if ( rgba[2] & 0x08 ) rgba[2] |= 0x07; */ \
    } while (0)

 #define TAG(x) s3v##x##_RGB555
 #include "spantmp.h"


 /* 32 bit, ARGB8888 color spanline and pixel functions
  */

 #undef INIT_MONO_PIXEL
 #define INIT_MONO_PIXEL(p, color) \
   p = PACK_COLOR_8888( color[3], color[0], color[1], color[2] )

 #define WRITE_RGBA( _x, _y, r, g, b, a ) \
    *(GLuint *)(buf + _x*4 + _y*pitch) = ((b <<  0) | \
 					 (g <<  8) | \
 					 (r << 16) | \
 					 (a << 24) )

 #define WRITE_PIXEL( _x, _y, p ) \
    *(GLuint *)(buf + _x*4 + _y*pitch) = p

 #define READ_RGBA( rgba, _x, _y ) \
 do { \
    GLuint p = *(GLuint *)(read_buf + _x*4 + _y*pitch); \
    rgba[0] = (p >> 16) & 0xff; \
    rgba[1] = (p >>  8) & 0xff; \
    rgba[2] = (p >>  0) & 0xff; \
    rgba[3] = (p >> 24) & 0xff; \
 } while (0)

 #define TAG(x) s3v##x##_ARGB8888
 #include "spantmp.h"


 /* 16 bit depthbuffer functions.
  */
 #define WRITE_DEPTH( _x, _y, d ) \
    *(GLushort *)(buf + _x*2 + _y*dPriv->w*2) = d

 #define READ_DEPTH( d, _x, _y ) \
    d = *(GLushort *)(buf + _x*2 + _y*dPriv->w*2);

 #define TAG(x) s3v##x##_16
 #include "depthtmp.h"


 /* 32 bit depthbuffer functions.
  */
 #if 0
 #define WRITE_DEPTH( _x, _y, d )	\
    *(GLuint *)(buf + _x*4 + _y*pitch) = d;

 #define READ_DEPTH( d, _x, _y )		\
    d = *(GLuint *)(buf + _x*4 + _y*pitch);

 #define TAG(x) s3v##x##_32
 #include "depthtmp.h"
 #endif


 /* 24/8 bit interleaved depth/stencil functions
  */
 #if 0
 #define WRITE_DEPTH( _x, _y, d ) { \
    GLuint tmp = *(GLuint *)(buf + _x*4 + _y*pitch);	\
    tmp &= 0xff; \
    tmp |= (d) & 0xffffff00; \
    *(GLuint *)(buf + _x*4 + _y*pitch) = tmp; \
 }

 #define READ_DEPTH( d, _x, _y ) \
    d = *(GLuint *)(buf + _x*4 + _y*pitch) & ~0xff


 #define TAG(x) s3v##x##_24_8
 #include "depthtmp.h"

 #define WRITE_STENCIL( _x, _y, d ) { \
    GLuint tmp = *(GLuint *)(buf + _x*4 + _y*pitch);	\
    tmp &= 0xffffff00; \
    tmp |= d & 0xff; \
    *(GLuint *)(buf + _x*4 + _y*pitch) = tmp; \
 }

 #define READ_STENCIL( d, _x, _y ) \
    d = *(GLuint *)(buf + _x*4 + _y*pitch) & 0xff

 #define TAG(x) s3v##x##_24_8
 #include "stenciltmp.h"

 #endif

 static void s3vSetBuffer( GLcontext *ctx, GLframebuffer *colorBuffer,
 			  GLuint bufferBit )
 {
    s3vContextPtr vmesa = S3V_CONTEXT(ctx);

    switch ( bufferBit ) {
    case BUFFER_BIT_FRONT_LEFT:
       vmesa->drawOffset = vmesa->readOffset = 0;
       break;
    case BUFFER_BIT_BACK_LEFT:
       vmesa->drawOffset = vmesa->readOffset = vmesa->driScreen->fbHeight *
                                               vmesa->driScreen->fbWidth *
                                               vmesa->s3vScreen->cpp;
       break;
    }
 }


 void s3vInitSpanFuncs( GLcontext *ctx )
 {
    s3vContextPtr vmesa = S3V_CONTEXT(ctx);
    struct swrast_device_driver *swdd = _swrast_GetDeviceDriverReference(ctx);

    swdd->SetBuffer = s3vSetBuffer;

 #if 0
    switch ( vmesa->s3vScreen->cpp ) {
    case 2:
       swdd->WriteRGBASpan	= s3vWriteRGBASpan_RGB555;
       swdd->WriteRGBSpan	= s3vWriteRGBSpan_RGB555;
       swdd->WriteMonoRGBASpan	= s3vWriteMonoRGBASpan_RGB555;
       swdd->WriteRGBAPixels	= s3vWriteRGBAPixels_RGB555;
       swdd->WriteMonoRGBAPixels	= s3vWriteMonoRGBAPixels_RGB555;
       swdd->ReadRGBASpan	= s3vReadRGBASpan_RGB555;
       swdd->ReadRGBAPixels      = s3vReadRGBAPixels_RGB555;
       break;

    case 4:
       swdd->WriteRGBASpan	= s3vWriteRGBASpan_ARGB8888;
       swdd->WriteRGBSpan	= s3vWriteRGBSpan_ARGB8888;
       swdd->WriteMonoRGBASpan   = s3vWriteMonoRGBASpan_ARGB8888;
       swdd->WriteRGBAPixels     = s3vWriteRGBAPixels_ARGB8888;
       swdd->WriteMonoRGBAPixels = s3vWriteMonoRGBAPixels_ARGB8888;
 #if 1
       swdd->ReadRGBASpan    = s3vReadRGBASpan_ARGB8888;
 #else
       swdd->ReadRGBASpan    = s3vReadRGBASpan8888;
 #endif
       swdd->ReadRGBAPixels  = s3vReadRGBAPixels_ARGB8888;
       break;

    default:
       break;
    }
 #endif

    switch ( vmesa->glCtx->Visual.depthBits ) {
    case 15:
    case 16:
 #if 0
       swdd->ReadDepthSpan	= s3vReadDepthSpan_16;
       swdd->WriteDepthSpan	= s3vWriteDepthSpan_16;
       swdd->ReadDepthPixels	= s3vReadDepthPixels_16;
       swdd->WriteDepthPixels	= s3vWriteDepthPixels_16;
 #endif
       break;

 #if 0
    case 24:
       swdd->ReadDepthSpan	= s3vReadDepthSpan_24_8;
       swdd->WriteDepthSpan	= s3vWriteDepthSpan_24_8;
       swdd->ReadDepthPixels	= s3vReadDepthPixels_24_8;
       swdd->WriteDepthPixels	= s3vWriteDepthPixels_24_8;

       swdd->ReadStencilSpan	= s3vReadStencilSpan_24_8;
       swdd->WriteStencilSpan	= s3vWriteStencilSpan_24_8;
       swdd->ReadStencilPixels	= s3vReadStencilPixels_24_8;
       swdd->WriteStencilPixels	= s3vWriteStencilPixels_24_8;
       break;
 #endif

    default:
       break;
    }
 }


 /**
  * Plug in the Get/Put routines for the given driRenderbuffer.
  */
 void
 s3vSetSpanFunctions(driRenderbuffer *drb, const GLvisual *vis)
 {
    if (drb->Base.InternalFormat == GL_RGBA) {
       if (vis->redBits == 5 && vis->greenBits == 6 && vis->blueBits == 5) {
          drb->Base.GetRow        = s3vReadRGBASpan_RGB555;
          drb->Base.GetValues     = s3vReadRGBAPixels_RGB555;
          drb->Base.PutRow        = s3vWriteRGBASpan_RGB555;
          drb->Base.PutRowRGB     = s3vWriteRGBSpan_RGB555;
          drb->Base.PutMonoRow    = s3vWriteMonoRGBASpan_RGB555;
          drb->Base.PutValues     = s3vWriteRGBAPixels_RGB555;
          drb->Base.PutMonoValues = s3vWriteMonoRGBAPixels_RGB555;
       }
       else {
          drb->Base.GetRow        = s3vReadRGBASpan_ARGB8888;
          drb->Base.GetValues     = s3vReadRGBAPixels_ARGB8888;
          drb->Base.PutRow        = s3vWriteRGBASpan_ARGB8888;
          drb->Base.PutRowRGB     = s3vWriteRGBSpan_ARGB8888;
          drb->Base.PutMonoRow    = s3vWriteMonoRGBASpan_ARGB8888;
          drb->Base.PutValues     = s3vWriteRGBAPixels_ARGB8888;
          drb->Base.PutMonoValues = s3vWriteMonoRGBAPixels_ARGB8888;
       }
    }
    else if (drb->Base.InternalFormat == GL_DEPTH_COMPONENT16) {
       drb->Base.GetRow        = s3vReadDepthSpan_16;
       drb->Base.GetValues     = s3vReadDepthPixels_16;
       drb->Base.PutRow        = s3vWriteDepthSpan_16;
       drb->Base.PutMonoRow    = s3vWriteMonoDepthSpan_16;
       drb->Base.PutValues     = s3vWriteDepthPixels_16;
       drb->Base.PutMonoValues = NULL;
    }
    else if (drb->Base.InternalFormat == GL_DEPTH_COMPONENT24) {
       drb->Base.GetRow = NULL;
       drb->Base.GetValues = NULL;
       drb->Base.PutRow = NULL;
       drb->Base.PutMonoRow = NULL;
       drb->Base.PutValues = NULL;
       drb->Base.PutMonoValues = NULL;
    }
    else if (drb->Base.InternalFormat == GL_STENCIL_INDEX8_EXT) {
       drb->Base.GetRow = NULL;
       drb->Base.GetValues = NULL;
       drb->Base.PutRow = NULL;
       drb->Base.PutMonoRow = NULL;
       drb->Base.PutValues = NULL;
       drb->Base.PutMonoValues = NULL;
    }
 }
	/*
	* Author: Max Lingua <sunmax@libero.it>
	*/

	#include "s3v_context.h"
	#include "s3v_lock.h"

	#include "swrast/swrast.h"

	#define _SPANLOCK 1
	#define DBG 0

	#define LOCAL_VARS \
	s3vContextPtr vmesa = S3V_CONTEXT(ctx); \
	s3vScreenPtr s3vscrn = vmesa->s3vScreen; \
	__DRIscreenPrivate *sPriv = vmesa->driScreen; \
	__DRIdrawablePrivate *dPriv = vmesa->driDrawable; \
	GLuint pitch = ( (vmesa->Flags & S3V_BACK_BUFFER) ? \
	((dPriv->w+31)&~31) * s3vscrn->cpp \
	: sPriv->fbWidth * s3vscrn->cpp); \
	GLuint height = dPriv->h; \
	char *buf = ( (vmesa->Flags & S3V_BACK_BUFFER) ? \
	(char *)(sPriv->pFB + vmesa->drawOffset) \
	: (char *)(sPriv->pFB + vmesa->drawOffset \
	+ dPriv->x * s3vscrn->cpp + dPriv->y * pitch) ); \
	char *read_buf = ( (vmesa->Flags & S3V_BACK_BUFFER) ? \
	(char *)(sPriv->pFB + vmesa->drawOffset) \
	: (char *)(sPriv->pFB + vmesa->drawOffset \
	+ dPriv->x * s3vscrn->cpp + dPriv->y * pitch) ); \
	GLuint p; \
	(void) read_buf; (void) buf; (void) p; (void) pitch

	/* FIXME! Depth/Stencil read/writes don't work ! */
	#define LOCAL_DEPTH_VARS \
	s3vScreenPtr s3vscrn = vmesa->s3vScreen; \
	__DRIdrawablePrivate *dPriv = vmesa->driDrawable; \
	__DRIscreenPrivate *sPriv = vmesa->driScreen; \
	GLuint pitch = s3vscrn->depthPitch; \
	GLuint height = dPriv->h; \
	char buf = (char )(sPriv->pFB + \
	s3vscrn->depthOffset); /* + \
	dPriv->x * s3vscrn->cpp + \
	dPriv->y * pitch)*/ \
	(void) pitch

	#define LOCAL_STENCIL_VARS LOCAL_DEPTH_VARS


	#define CLIPPIXEL( _x, _y ) \
	((_x >= minx) && (_x < maxx) && (_y >= miny) && (_y < maxy))


	#define CLIPSPAN( _x, _y, _n, _x1, _n1, _i ) \
	if ( _y < miny \|\| _y >= maxy ) { \
	_n1 = 0, _x1 = x; \
	} else { \
	_n1 = _n; \
	_x1 = _x; \
	if ( _x1 < minx ) \
	_i += (minx-_x1), n1 -= (minx-_x1), _x1 = minx; \
	if ( _x1 + _n1 >= maxx ) \
	n1 -= (_x1 + n1 - maxx); \
	}

	#define Y_FLIP( _y ) (height - _y - 1)

	#if _SPANLOCK /* OK, we lock */

	#define HW_LOCK() \
	s3vContextPtr vmesa = S3V_CONTEXT(ctx); \
	(void) vmesa; \
	DMAFLUSH(); \
	S3V_SIMPLE_FLUSH_LOCK(vmesa);
	#define HW_UNLOCK() S3V_SIMPLE_UNLOCK(vmesa);

	#else /* plz, don't lock */

	#define HW_LOCK() \
	s3vContextPtr vmesa = S3V_CONTEXT(ctx); \
	(void) vmesa; \
	DMAFLUSH();
	#define HW_UNLOCK()

	#endif

	#define HW_CLIPLOOP() \
	do { \
	__DRIdrawablePrivate *dPriv = vmesa->driDrawable; \
	int _nc = dPriv->numClipRects; \
	\
	while ( _nc-- ) { \
	int minx = dPriv->pClipRects[_nc].x1 - dPriv->x; \
	int miny = dPriv->pClipRects[_nc].y1 - dPriv->y; \
	int maxx = dPriv->pClipRects[_nc].x2 - dPriv->x; \
	int maxy = dPriv->pClipRects[_nc].y2 - dPriv->y;

	#define HW_ENDCLIPLOOP() \
	} \
	} while (0)


	/* ================================================================
	* Color buffer
	*/

	/* 16 bit, RGB565 color spanline and pixel functions
	*/
	#define INIT_MONO_PIXEL(p, color) \
	p = S3VIRGEPACKCOLOR555( color[0], color[1], color[2], color[3] )

	#define WRITE_RGBA( _x, _y, r, g, b, a ) \
	do { \
	(GLushort )(buf + _x2 + _ypitch) = ((((int)r & 0xf8) << 7) \| \
	(((int)g & 0xf8) << 2) \| \
	(((int)b & 0xf8) >> 3)); \
	DEBUG(("buf=0x%x drawOffset=0x%x dPriv->x=%i s3vscrn->cpp=%i dPriv->y=%i pitch=%i\n", \
	sPriv->pFB, vmesa->drawOffset, dPriv->x, s3vscrn->cpp, dPriv->y, pitch)); \
	DEBUG(("dPriv->w = %i\n", dPriv->w)); \
	} while(0)

	#define WRITE_PIXEL( _x, _y, p ) \
	(GLushort )(buf + _x2 + _ypitch) = p

	#define READ_RGBA( rgba, _x, _y ) \
	do { \
	GLushort p = (GLushort )(read_buf + _x2 + _ypitch); \
	rgba[0] = (p >> 7) & 0xf8; \
	rgba[1] = (p >> 2) & 0xf8; \
	rgba[2] = (p << 3) & 0xf8; \
	rgba[3] = 0xff; /*
	if ( rgba[0] & 0x08 ) rgba[0] \|= 0x07; \
	if ( rgba[1] & 0x04 ) rgba[1] \|= 0x03; \
	if ( rgba[2] & 0x08 ) rgba[2] \|= 0x07; */ \
	} while (0)

	#define TAG(x) s3v##x##_RGB555
	#include "spantmp.h"


	/* 32 bit, ARGB8888 color spanline and pixel functions
	*/

	#undef INIT_MONO_PIXEL
	#define INIT_MONO_PIXEL(p, color) \
	p = PACK_COLOR_8888( color[3], color[0], color[1], color[2] )

	#define WRITE_RGBA( _x, _y, r, g, b, a ) \
	(GLuint )(buf + _x4 + _ypitch) = ((b << 0) \| \
	(g << 8) \| \
	(r << 16) \| \
	(a << 24) )

	#define WRITE_PIXEL( _x, _y, p ) \
	(GLuint )(buf + _x4 + _ypitch) = p

	#define READ_RGBA( rgba, _x, _y ) \
	do { \
	GLuint p = (GLuint )(read_buf + _x4 + _ypitch); \
	rgba[0] = (p >> 16) & 0xff; \
	rgba[1] = (p >> 8) & 0xff; \
	rgba[2] = (p >> 0) & 0xff; \
	rgba[3] = (p >> 24) & 0xff; \
	} while (0)

	#define TAG(x) s3v##x##_ARGB8888
	#include "spantmp.h"


	/* 16 bit depthbuffer functions.
	*/
	#define WRITE_DEPTH( _x, _y, d ) \
	(GLushort )(buf + _x2 + _ydPriv->w*2) = d

	#define READ_DEPTH( d, _x, _y ) \
	d = (GLushort )(buf + _x2 + _ydPriv->w*2);

	#define TAG(x) s3v##x##_16
	#include "depthtmp.h"




	/* 32 bit depthbuffer functions.
	*/
	#if 0
	#define WRITE_DEPTH( _x, _y, d ) \
	(GLuint )(buf + _x4 + _ypitch) = d;

	#define READ_DEPTH( d, _x, _y ) \
	d = (GLuint )(buf + _x4 + _ypitch);

	#define TAG(x) s3v##x##_32
	#include "depthtmp.h"
	#endif


	/* 24/8 bit interleaved depth/stencil functions
	*/
	#if 0
	#define WRITE_DEPTH( _x, _y, d ) { \
	GLuint tmp = (GLuint )(buf + _x4 + _ypitch); \
	tmp &= 0xff; \
	tmp \|= (d) & 0xffffff00; \
	(GLuint )(buf + _x4 + _ypitch) = tmp; \
	}

	#define READ_DEPTH( d, _x, _y ) \
	d = (GLuint )(buf + _x4 + _ypitch) & ~0xff


	#define TAG(x) s3v##x##_24_8
	#include "depthtmp.h"

	#define WRITE_STENCIL( _x, _y, d ) { \
	GLuint tmp = (GLuint )(buf + _x4 + _ypitch); \
	tmp &= 0xffffff00; \
	tmp \|= d & 0xff; \
	(GLuint )(buf + _x4 + _ypitch) = tmp; \
	}

	#define READ_STENCIL( d, _x, _y ) \
	d = (GLuint )(buf + _x4 + _ypitch) & 0xff

	#define TAG(x) s3v##x##_24_8
	#include "stenciltmp.h"

	#endif

	static void s3vSetBuffer( GLcontext ctx, GLframebuffer colorBuffer,
	GLuint bufferBit )
	{
	s3vContextPtr vmesa = S3V_CONTEXT(ctx);

	switch ( bufferBit ) {
	case BUFFER_BIT_FRONT_LEFT:
	vmesa->drawOffset = vmesa->readOffset = 0;
	break;
	case BUFFER_BIT_BACK_LEFT:
	vmesa->drawOffset = vmesa->readOffset = vmesa->driScreen->fbHeight *
	vmesa->driScreen->fbWidth *
	vmesa->s3vScreen->cpp;
	break;
	}
	}


	void s3vInitSpanFuncs( GLcontext *ctx )
	{
	s3vContextPtr vmesa = S3V_CONTEXT(ctx);
	struct swrast_device_driver *swdd = _swrast_GetDeviceDriverReference(ctx);

	swdd->SetBuffer = s3vSetBuffer;

	#if 0
	switch ( vmesa->s3vScreen->cpp ) {
	case 2:
	swdd->WriteRGBASpan = s3vWriteRGBASpan_RGB555;
	swdd->WriteRGBSpan = s3vWriteRGBSpan_RGB555;
	swdd->WriteMonoRGBASpan = s3vWriteMonoRGBASpan_RGB555;
	swdd->WriteRGBAPixels = s3vWriteRGBAPixels_RGB555;
	swdd->WriteMonoRGBAPixels = s3vWriteMonoRGBAPixels_RGB555;
	swdd->ReadRGBASpan = s3vReadRGBASpan_RGB555;
	swdd->ReadRGBAPixels = s3vReadRGBAPixels_RGB555;
	break;

	case 4:
	swdd->WriteRGBASpan = s3vWriteRGBASpan_ARGB8888;
	swdd->WriteRGBSpan = s3vWriteRGBSpan_ARGB8888;
	swdd->WriteMonoRGBASpan = s3vWriteMonoRGBASpan_ARGB8888;
	swdd->WriteRGBAPixels = s3vWriteRGBAPixels_ARGB8888;
	swdd->WriteMonoRGBAPixels = s3vWriteMonoRGBAPixels_ARGB8888;
	#if 1
	swdd->ReadRGBASpan = s3vReadRGBASpan_ARGB8888;
	#else
	swdd->ReadRGBASpan = s3vReadRGBASpan8888;
	#endif
	swdd->ReadRGBAPixels = s3vReadRGBAPixels_ARGB8888;
	break;

	default:
	break;
	}
	#endif

	switch ( vmesa->glCtx->Visual.depthBits ) {
	case 15:
	case 16:
	#if 0
	swdd->ReadDepthSpan = s3vReadDepthSpan_16;
	swdd->WriteDepthSpan = s3vWriteDepthSpan_16;
	swdd->ReadDepthPixels = s3vReadDepthPixels_16;
	swdd->WriteDepthPixels = s3vWriteDepthPixels_16;
	#endif
	break;

	#if 0
	case 24:
	swdd->ReadDepthSpan = s3vReadDepthSpan_24_8;
	swdd->WriteDepthSpan = s3vWriteDepthSpan_24_8;
	swdd->ReadDepthPixels = s3vReadDepthPixels_24_8;
	swdd->WriteDepthPixels = s3vWriteDepthPixels_24_8;

	swdd->ReadStencilSpan = s3vReadStencilSpan_24_8;
	swdd->WriteStencilSpan = s3vWriteStencilSpan_24_8;
	swdd->ReadStencilPixels = s3vReadStencilPixels_24_8;
	swdd->WriteStencilPixels = s3vWriteStencilPixels_24_8;
	break;
	#endif

	default:
	break;
	}
	}


	/**
	* Plug in the Get/Put routines for the given driRenderbuffer.
	*/
	void
	s3vSetSpanFunctions(driRenderbuffer drb, const GLvisual vis)
	{
	if (drb->Base.InternalFormat == GL_RGBA) {
	if (vis->redBits == 5 && vis->greenBits == 6 && vis->blueBits == 5) {
	drb->Base.GetRow = s3vReadRGBASpan_RGB555;
	drb->Base.GetValues = s3vReadRGBAPixels_RGB555;
	drb->Base.PutRow = s3vWriteRGBASpan_RGB555;
	drb->Base.PutRowRGB = s3vWriteRGBSpan_RGB555;
	drb->Base.PutMonoRow = s3vWriteMonoRGBASpan_RGB555;
	drb->Base.PutValues = s3vWriteRGBAPixels_RGB555;
	drb->Base.PutMonoValues = s3vWriteMonoRGBAPixels_RGB555;
	}
	else {
	drb->Base.GetRow = s3vReadRGBASpan_ARGB8888;
	drb->Base.GetValues = s3vReadRGBAPixels_ARGB8888;
	drb->Base.PutRow = s3vWriteRGBASpan_ARGB8888;
	drb->Base.PutRowRGB = s3vWriteRGBSpan_ARGB8888;
	drb->Base.PutMonoRow = s3vWriteMonoRGBASpan_ARGB8888;
	drb->Base.PutValues = s3vWriteRGBAPixels_ARGB8888;
	drb->Base.PutMonoValues = s3vWriteMonoRGBAPixels_ARGB8888;
	}
	}
	else if (drb->Base.InternalFormat == GL_DEPTH_COMPONENT16) {
	drb->Base.GetRow = s3vReadDepthSpan_16;
	drb->Base.GetValues = s3vReadDepthPixels_16;
	drb->Base.PutRow = s3vWriteDepthSpan_16;
	drb->Base.PutMonoRow = s3vWriteMonoDepthSpan_16;
	drb->Base.PutValues = s3vWriteDepthPixels_16;
	drb->Base.PutMonoValues = NULL;
	}
	else if (drb->Base.InternalFormat == GL_DEPTH_COMPONENT24) {
	drb->Base.GetRow = NULL;
	drb->Base.GetValues = NULL;
	drb->Base.PutRow = NULL;
	drb->Base.PutMonoRow = NULL;
	drb->Base.PutValues = NULL;
	drb->Base.PutMonoValues = NULL;
	}
	else if (drb->Base.InternalFormat == GL_STENCIL_INDEX8_EXT) {
	drb->Base.GetRow = NULL;
	drb->Base.GetValues = NULL;
	drb->Base.PutRow = NULL;
	drb->Base.PutMonoRow = NULL;
	drb->Base.PutValues = NULL;
	drb->Base.PutMonoValues = NULL;
	}
	}