fxddspan.c

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

 * This is more evil. We make Mesa run in 32bit depth, but
 * tha Voodoo HW can only handle 24bit depth. Well, exploiting
 * the pixel pipeline, we can achieve 24:8 format for greater
 * precision...
 * If anyone tells me how to really store 32bit values into the
 * depth buffer, I'll write the *_Z32 routines. Howver, bear in
 * mind that means running without stencil!
 */

/************************************************************************/
/*****                    Span functions (optimized)                *****/
/************************************************************************/

/*
 * Read a span of 15-bit RGB pixels.  Note, we don't worry about cliprects
 * since OpenGL says obscured pixels have undefined values.
 */
static void fxReadRGBASpan_ARGB1555 (const GLcontext * ctx,
                                     struct gl_renderbuffer *rb,
                                     GLuint n,
                                     GLint x, GLint y,
                                     GLubyte rgba[][4])
{
 fxMesaContext fxMesa = FX_CONTEXT(ctx);
 GrBuffer_t currentFB = GR_BUFFER_BACKBUFFER;
 GrLfbInfo_t info;
 info.size = sizeof(GrLfbInfo_t);
 if (grLfbLock(GR_LFB_READ_ONLY, currentFB,
               GR_LFBWRITEMODE_ANY, GR_ORIGIN_UPPER_LEFT, FXFALSE, &info)) {
    const GLint winX = 0;
    const GLint winY = fxMesa->height - 1;
    const GLushort *data16 = (const GLushort *)((const GLubyte *)info.lfbPtr +
	                                        (winY - y) * info.strideInBytes +
                                                (winX + x) * 2);
    const GLuint *data32 = (const GLuint *) data16;
    GLuint i, j;
    GLuint extraPixel = (n & 1);
    n -= extraPixel;

    for (i = j = 0; i < n; i += 2, j++) {
	GLuint pixel = data32[j];
	rgba[i][0] = FX_rgb_scale_5[(pixel >> 10) & 0x1F];
	rgba[i][1] = FX_rgb_scale_5[(pixel >> 5)  & 0x1F];
	rgba[i][2] = FX_rgb_scale_5[ pixel        & 0x1F];
	rgba[i][3] = (pixel & 0x8000) ? 255 : 0;
	rgba[i+1][0] = FX_rgb_scale_5[(pixel >> 26) & 0x1F];
	rgba[i+1][1] = FX_rgb_scale_5[(pixel >> 21) & 0x1F];
	rgba[i+1][2] = FX_rgb_scale_5[(pixel >> 16) & 0x1F];
	rgba[i+1][3] = (pixel & 0x80000000) ? 255 : 0;
    }
    if (extraPixel) {
       GLushort pixel = data16[n];
       rgba[n][0] = FX_rgb_scale_5[(pixel >> 10) & 0x1F];
       rgba[n][1] = FX_rgb_scale_5[(pixel >> 5)  & 0x1F];
       rgba[n][2] = FX_rgb_scale_5[ pixel        & 0x1F];
       rgba[n][3] = (pixel & 0x8000) ? 255 : 0;
    }

    grLfbUnlock(GR_LFB_READ_ONLY, currentFB);
 }
}

/*
 * Read a span of 16-bit RGB pixels.  Note, we don't worry about cliprects
 * since OpenGL says obscured pixels have undefined values.
 */
static void fxReadRGBASpan_RGB565 (const GLcontext * ctx,
                                   struct gl_renderbuffer *rb,
                                   GLuint n,
                                   GLint x, GLint y,
                                   GLubyte rgba[][4])
{
 fxMesaContext fxMesa = FX_CONTEXT(ctx);
 GrBuffer_t currentFB = GR_BUFFER_BACKBUFFER;
 GrLfbInfo_t info;
 info.size = sizeof(GrLfbInfo_t);
 if (grLfbLock(GR_LFB_READ_ONLY, currentFB,
               GR_LFBWRITEMODE_ANY, GR_ORIGIN_UPPER_LEFT, FXFALSE, &info)) {
    const GLint winX = 0;
    const GLint winY = fxMesa->height - 1;
    const GLushort *data16 = (const GLushort *)((const GLubyte *)info.lfbPtr +
	                                        (winY - y) * info.strideInBytes +
                                                (winX + x) * 2);
    const GLuint *data32 = (const GLuint *) data16;
    GLuint i, j;
    GLuint extraPixel = (n & 1);
    n -= extraPixel;

    for (i = j = 0; i < n; i += 2, j++) {
        GLuint pixel = data32[j];
	rgba[i][0] = FX_rgb_scale_5[(pixel >> 11) & 0x1F];
	rgba[i][1] = FX_rgb_scale_6[(pixel >> 5)  & 0x3F];
	rgba[i][2] = FX_rgb_scale_5[ pixel        & 0x1F];
	rgba[i][3] = 255;
	rgba[i+1][0] = FX_rgb_scale_5[(pixel >> 27) & 0x1F];
	rgba[i+1][1] = FX_rgb_scale_6[(pixel >> 21) & 0x3F];
	rgba[i+1][2] = FX_rgb_scale_5[(pixel >> 16) & 0x1F];
	rgba[i+1][3] = 255;
    }
    if (extraPixel) {
       GLushort pixel = data16[n];
       rgba[n][0] = FX_rgb_scale_5[(pixel >> 11) & 0x1F];
       rgba[n][1] = FX_rgb_scale_6[(pixel >> 5)  & 0x3F];
       rgba[n][2] = FX_rgb_scale_5[ pixel        & 0x1F];
       rgba[n][3] = 255;
    }

    grLfbUnlock(GR_LFB_READ_ONLY, currentFB);
 }
}

/*
 * Read a span of 32-bit RGB pixels.  Note, we don't worry about cliprects
 * since OpenGL says obscured pixels have undefined values.
 */
static void fxReadRGBASpan_ARGB8888 (const GLcontext * ctx,
                                     struct gl_renderbuffer *rb,
                                     GLuint n,
                                     GLint x, GLint y,
                                     GLubyte rgba[][4])
{
 fxMesaContext fxMesa = FX_CONTEXT(ctx);
 GrBuffer_t currentFB = GR_BUFFER_BACKBUFFER;
 GLuint i;
 grLfbReadRegion(currentFB, x, fxMesa->height - 1 - y, n, 1, n * 4, rgba);
 for (i = 0; i < n; i++) {
     GLubyte c = rgba[i][0];
     rgba[i][0] = rgba[i][2];
     rgba[i][2] = c;
 }
}


/************************************************************************/
/*****                    Depth functions (optimized)               *****/
/************************************************************************/

static void
fxReadDepthSpan_Z16(GLcontext * ctx, struct gl_renderbuffer *rb,
		    GLuint n, GLint x, GLint y, GLuint depth[])
{
   fxMesaContext fxMesa = FX_CONTEXT(ctx);
   GLint bottom = fxMesa->height - 1;
   GLushort depth16[MAX_WIDTH];
   GLuint i;

   if (TDFX_DEBUG & VERBOSE_DRIVER) {
      fprintf(stderr, "fxReadDepthSpan_Z16(...)\n");
   }

   grLfbReadRegion(GR_BUFFER_AUXBUFFER, x, bottom - y, n, 1, 0, depth16);
   for (i = 0; i < n; i++) {
      depth[i] = depth16[i];
   }
}


static void
fxReadDepthSpan_Z24(GLcontext * ctx, struct gl_renderbuffer *rb,
		    GLuint n, GLint x, GLint y, GLuint depth[])
{
   fxMesaContext fxMesa = FX_CONTEXT(ctx);
   GLint bottom = fxMesa->height - 1;
   GLuint i;

   if (TDFX_DEBUG & VERBOSE_DRIVER) {
      fprintf(stderr, "fxReadDepthSpan_Z24(...)\n");
   }

   grLfbReadRegion(GR_BUFFER_AUXBUFFER, x, bottom - y, n, 1, 0, depth);
   for (i = 0; i < n; i++) {
      depth[i] &= 0xffffff;
   }
}


/************************************************************************/
/*****                    Stencil functions (optimized)             *****/
/************************************************************************/

static void
fxWriteStencilSpan (GLcontext *ctx, struct gl_renderbuffer *rb,
                    GLuint n, GLint x, GLint y,
                    const GLstencil stencil[], const GLubyte mask[])
{
 /*
  * XXX todo
  */
}

static void
fxReadStencilSpan(GLcontext * ctx, struct gl_renderbuffer *rb,
		  GLuint n, GLint x, GLint y, GLstencil stencil[])
{
   fxMesaContext fxMesa = FX_CONTEXT(ctx);
   GLint bottom = fxMesa->height - 1;
   GLuint zs32[MAX_WIDTH];
   GLuint i;

   if (TDFX_DEBUG & VERBOSE_DRIVER) {
      fprintf(stderr, "fxReadStencilSpan(...)\n");
   }

   grLfbReadRegion(GR_BUFFER_AUXBUFFER, x, bottom - y, n, 1, 0, zs32);
   for (i = 0; i < n; i++) {
      stencil[i] = zs32[i] >> 24;
   }
}

static void
fxWriteStencilPixels (GLcontext *ctx, struct gl_renderbuffer *rb, GLuint n,
                      const GLint x[], const GLint y[],
                      const GLstencil stencil[],
                      const GLubyte mask[])
{
 /*
  * XXX todo
  */
}

static void
fxReadStencilPixels (GLcontext *ctx, struct gl_renderbuffer *rb, GLuint n,
                     const GLint x[], const GLint y[],
                     GLstencil stencil[])
{
 /*
  * XXX todo
  */
}


void
fxSetupDDSpanPointers(GLcontext * ctx)
{
   struct swrast_device_driver *swdd = _swrast_GetDeviceDriverReference( ctx );
   fxMesaContext fxMesa = FX_CONTEXT(ctx);

   switch (fxMesa->colDepth) {
          case 15:
               swdd->WriteRGBASpan = tdfxWriteRGBASpan_ARGB1555;
               swdd->WriteRGBSpan = tdfxWriteRGBSpan_ARGB1555;
               swdd->WriteRGBAPixels = tdfxWriteRGBAPixels_ARGB1555;
               swdd->WriteMonoRGBASpan = tdfxWriteMonoRGBASpan_ARGB1555;
               swdd->WriteMonoRGBAPixels = tdfxWriteMonoRGBAPixels_ARGB1555;
               swdd->ReadRGBASpan = /*td*/fxReadRGBASpan_ARGB1555;
               swdd->ReadRGBAPixels = tdfxReadRGBAPixels_ARGB1555;

               swdd->WriteDepthSpan = tdfxWriteDepthSpan_Z16;
               swdd->WriteDepthPixels = tdfxWriteDepthPixels_Z16;
               swdd->ReadDepthSpan = /*td*/fxReadDepthSpan_Z16;
               swdd->ReadDepthPixels = tdfxReadDepthPixels_Z16;
               break;
          case 16:
               swdd->WriteRGBASpan = tdfxWriteRGBASpan_RGB565;
               swdd->WriteRGBSpan = tdfxWriteRGBSpan_RGB565;
               swdd->WriteRGBAPixels = tdfxWriteRGBAPixels_RGB565;
               swdd->WriteMonoRGBASpan = tdfxWriteMonoRGBASpan_RGB565;
               swdd->WriteMonoRGBAPixels = tdfxWriteMonoRGBAPixels_RGB565;
               swdd->ReadRGBASpan = /*td*/fxReadRGBASpan_RGB565;
               swdd->ReadRGBAPixels = tdfxReadRGBAPixels_RGB565;

               swdd->WriteDepthSpan = tdfxWriteDepthSpan_Z16;
               swdd->WriteDepthPixels = tdfxWriteDepthPixels_Z16;
               swdd->ReadDepthSpan = /*td*/fxReadDepthSpan_Z16;
               swdd->ReadDepthPixels = tdfxReadDepthPixels_Z16;
               break;
          case 32:
               swdd->WriteRGBASpan = tdfxWriteRGBASpan_ARGB8888;
               swdd->WriteRGBSpan = tdfxWriteRGBSpan_ARGB8888;
               swdd->WriteRGBAPixels = tdfxWriteRGBAPixels_ARGB8888;
               swdd->WriteMonoRGBASpan = tdfxWriteMonoRGBASpan_ARGB8888;
               swdd->WriteMonoRGBAPixels = tdfxWriteMonoRGBAPixels_ARGB8888;
               swdd->ReadRGBASpan = /*td*/fxReadRGBASpan_ARGB8888;
               swdd->ReadRGBAPixels = tdfxReadRGBAPixels_ARGB8888;

               swdd->WriteDepthSpan = tdfxWriteDepthSpan_Z24;
               swdd->WriteDepthPixels = tdfxWriteDepthPixels_Z24;
               swdd->ReadDepthSpan = /*td*/fxReadDepthSpan_Z24;
               swdd->ReadDepthPixels = tdfxReadDepthPixels_Z24;
               break;
   }

   if (fxMesa->haveHwStencil) {
      swdd->WriteStencilSpan = fxWriteStencilSpan;
      swdd->ReadStencilSpan = fxReadStencilSpan;
      swdd->WriteStencilPixels = fxWriteStencilPixels;
      swdd->ReadStencilPixels = fxReadStencilPixels;
   }
#if 0
   swdd->WriteCI8Span		= NULL;
   swdd->WriteCI32Span		= NULL;
   swdd->WriteMonoCISpan	= NULL;
   swdd->WriteCI32Pixels	= NULL;
   swdd->WriteMonoCIPixels	= NULL;
   swdd->ReadCI32Span		= NULL;
   swdd->ReadCI32Pixels		= NULL;

   swdd->SpanRenderStart        = tdfxSpanRenderStart; /* BEGIN_BOARD_LOCK */
   swdd->SpanRenderFinish       = tdfxSpanRenderFinish; /* END_BOARD_LOCK */
#endif
}


#else


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

extern int gl_fx_dummy_function_span(void);
int
gl_fx_dummy_function_span(void)
{
   return 0;
}

#endif /* FX */