-/* $Id: stencil.c,v 1.11 1999/12/04 21:23:55 brianp Exp $ */
+/* $Id: stencil.c,v 1.12 1999/12/10 16:15:04 brianp Exp $ */
/*
* Mesa 3-D graphics library
/*
* Apply the given stencil operator to the array of stencil values.
* Don't touch stencil[i] if mask[i] is zero.
- * Input: n - number of pixels in the span
+ * Input: n - size of stencil array
* oper - the stencil buffer operator
* stencil - array of stencil values
* mask - array [n] of flag: 1=apply operator, 0=don't apply operator
+ * Output: stencil - modified values
*/
-static void apply_stencil_op( GLcontext *ctx, GLenum oper,
- GLuint n, GLstencil stencil[], GLubyte mask[] )
+static void apply_stencil_op( const GLcontext *ctx, GLenum oper,
+ GLuint n, GLstencil stencil[],
+ const GLubyte mask[] )
{
const GLstencil ref = ctx->Stencil.Ref;
const GLstencil wrtmask = ctx->Stencil.WriteMask;
for (i=0;i<n;i++) {
if (mask[i]) {
GLstencil s = stencil[i];
- stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (stencil[i]+1)));
+ stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (s+1)));
}
}
}
for (i=0;i<n;i++) {
if (mask[i]) {
GLstencil s = stencil[i];
- stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (stencil[i]-1)));
+ stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (s-1)));
}
}
}
/*
- * Apply stencil test to a span of pixels before depth buffering.
- * Input: n - number of pixels in the span
- * x, y - coordinate of left-most pixel in the span
+ * Apply stencil test to an array of stencil values (before depth buffering).
+ * Input: n - number of pixels in the array
+ * stencil - array of [n] stencil values
* mask - array [n] of flag: 0=skip the pixel, 1=stencil the pixel
* Output: mask - pixels which fail the stencil test will have their
* mask flag set to 0.
- * Return: 0 = all pixels failed, 1 = zero or more pixels passed.
+ * stencil - updated stencil values (where the test passed)
+ * Return: GL_FALSE = all pixels failed, GL_TRUE = zero or more pixels passed.
*/
-GLint gl_stencil_span( GLcontext *ctx,
- GLuint n, GLint x, GLint y, GLubyte mask[] )
+static GLboolean
+do_stencil_test( GLcontext *ctx, GLuint n, GLstencil stencil[],
+ GLubyte mask[] )
{
- GLubyte fail[MAX_WIDTH];
- GLint allfail = 0;
+ GLubyte fail[PB_SIZE];
+ GLboolean allfail = GL_FALSE;
GLuint i;
GLstencil r, s;
- GLstencil *stencil;
- stencil = STENCIL_ADDRESS( x, y );
+ ASSERT(n <= PB_SIZE);
/*
* Perform stencil test. The results of this operation are stored
fail[i] = 0;
}
}
- allfail = 1;
+ allfail = GL_TRUE;
break;
case GL_LESS:
r = (GLstencil) (ctx->Stencil.Ref & ctx->Stencil.ValueMask);
apply_stencil_op( ctx, ctx->Stencil.FailFunc, n, stencil, fail );
}
- return (allfail) ? 0 : 1;
+ return !allfail;
}
/*
- * Apply the combination depth-buffer/stencil operator to a span of pixels.
+ * Apply stencil and depth testing to an array of pixels.
+ * Hardware or software stencil buffer acceptable.
* Input: n - number of pixels in the span
- * x, y - location of leftmost pixel in span
* z - array [n] of z values
- * Input: mask - array [n] of flags (1=test this pixel, 0=skip the pixel)
- * Output: mask - array [n] of flags (1=depth test passed, 0=failed)
+ * stencil - array [n] of stencil values
+ * mask - array [n] of flags (1=test this pixel, 0=skip the pixel)
+ * Output: stencil - modified stencil values
+ * mask - array [n] of flags (1=stencil and depth test passed)
+ * Return: GL_TRUE - all fragments failed the testing
+ * GL_FALSE - one or more fragments passed the testing
+ *
*/
-void gl_depth_stencil_span( GLcontext *ctx,
- GLuint n, GLint x, GLint y, const GLdepth z[],
- GLubyte mask[] )
+static GLboolean
+stencil_and_depth_test_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
+ const GLdepth z[], GLstencil stencil[],
+ GLubyte mask[] )
{
- GLstencil *stencil = STENCIL_ADDRESS(x, y);
+ ASSERT(ctx->Stencil.Enabled);
+ ASSERT(n <= PB_SIZE);
+
+ /*
+ * Apply the stencil test to the fragments.
+ * failMask[i] is 1 if the stencil test failed.
+ */
+ if (do_stencil_test( ctx, n, stencil, mask ) == GL_FALSE) {
+ /* all fragments failed the stencil test, we're done. */
+ return GL_FALSE;
+ }
+
+ /*
+ * Some fragments passed the stencil test, apply depth test to them
+ * and apply Zpass and Zfail stencil ops.
+ */
if (ctx->Depth.Test==GL_FALSE) {
/*
* No depth buffer, just apply zpass stencil function to active pixels.
apply_stencil_op( ctx, ctx->Stencil.ZPassFunc, n, stencil, passmask );
}
}
+
+ return GL_TRUE; /* one or more fragments passed both tests */
+}
+
+
+
+/*
+ * Apply stencil and depth testing to the span of pixels.
+ * Both software and hardware stencil buffers are acceptable.
+ * Input: n - number of pixels in the span
+ * x, y - location of leftmost pixel in span
+ * z - array [n] of z values
+ * mask - array [n] of flags (1=test this pixel, 0=skip the pixel)
+ * Output: mask - array [n] of flags (1=stencil and depth test passed)
+ * Return: GL_TRUE - all fragments failed the testing
+ * GL_FALSE - one or more fragments passed the testing
+ *
+ */
+GLboolean
+gl_stencil_and_depth_test_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
+ const GLdepth z[], GLubyte mask[] )
+{
+ GLstencil stencilRow[MAX_WIDTH];
+ GLstencil *stencil;
+ GLboolean result;
+
+ ASSERT(ctx->Stencil.Enabled);
+ ASSERT(n <= MAX_WIDTH);
+
+ /* Get initial stencil values */
+ if (ctx->Driver.WriteStencilSpan) {
+ ASSERT(ctx->Driver.ReadStencilSpan);
+ /* Get stencil values from the hardware stencil buffer */
+ (*ctx->Driver.ReadStencilSpan)(ctx, n, x, y, stencilRow);
+ stencil = stencilRow;
+ }
+ else {
+ /* software stencil buffer */
+ stencil = STENCIL_ADDRESS(x, y);
+ }
+
+ /* do all the stencil/depth testing/updating */
+ result = stencil_and_depth_test_span( ctx, n, x, y, z, stencil, mask );
+
+ if (ctx->Driver.WriteStencilSpan) {
+ /* Write updated stencil values into hardware stencil buffer */
+ (ctx->Driver.WriteStencilSpan)(ctx, n, x, y, stencil, mask );
+ }
+
+ return result;
}
/*
* Apply the given stencil operator for each pixel in the array whose
- * mask flag is set.
+ * mask flag is set. This is for software stencil buffers only.
* Input: n - number of pixels in the span
* x, y - array of [n] pixels
* operator - the stencil buffer operator
* mask - array [n] of flag: 1=apply operator, 0=don't apply operator
*/
-static void apply_stencil_op_to_pixels( GLcontext *ctx,
- GLuint n, const GLint x[],
- const GLint y[],
- GLenum oper, GLubyte mask[] )
+static void
+apply_stencil_op_to_pixels( const GLcontext *ctx,
+ GLuint n, const GLint x[], const GLint y[],
+ GLenum oper, const GLubyte mask[] )
{
+ const GLstencil ref = ctx->Stencil.Ref;
+ const GLstencil wrtmask = ctx->Stencil.WriteMask;
+ const GLstencil invmask = (GLstencil) (~ctx->Stencil.WriteMask);
GLuint i;
- GLstencil ref;
- GLstencil wrtmask, invmask;
-
- wrtmask = ctx->Stencil.WriteMask;
- invmask = (GLstencil) (~ctx->Stencil.WriteMask);
- ref = ctx->Stencil.Ref;
+ ASSERT(!ctx->Driver.WriteStencilSpan); /* software stencil buffer only! */
switch (oper) {
case GL_KEEP:
/*
* Apply stencil test to an array of pixels before depth buffering.
+ * Used for software stencil buffer only.
* Input: n - number of pixels in the span
* x, y - array of [n] pixels to stencil
* mask - array [n] of flag: 0=skip the pixel, 1=stencil the pixel
* mask flag set to 0.
* Return: 0 = all pixels failed, 1 = zero or more pixels passed.
*/
-GLint gl_stencil_pixels( GLcontext *ctx,
- GLuint n, const GLint x[], const GLint y[],
- GLubyte mask[] )
+static GLboolean
+stencil_test_pixels( GLcontext *ctx, GLuint n,
+ const GLint x[], const GLint y[], GLubyte mask[] )
{
GLubyte fail[PB_SIZE];
GLstencil r, s;
GLuint i;
- GLint allfail = 0;
+ GLboolean allfail = GL_FALSE;
+
+ ASSERT(!ctx->Driver.WriteStencilSpan); /* software stencil buffer only! */
/*
* Perform stencil test. The results of this operation are stored
fail[i] = 0;
}
}
- allfail = 1;
+ allfail = GL_TRUE;
break;
case GL_LESS:
r = (GLstencil) (ctx->Stencil.Ref & ctx->Stencil.ValueMask);
return 0;
}
- apply_stencil_op_to_pixels( ctx, n, x, y, ctx->Stencil.FailFunc, fail );
+ if (ctx->Stencil.FailFunc != GL_KEEP) {
+ apply_stencil_op_to_pixels( ctx, n, x, y, ctx->Stencil.FailFunc, fail );
+ }
- return (allfail) ? 0 : 1;
+ return !allfail;
}
/*
- * Apply the combination depth-buffer/stencil operator to a span of pixels.
- * Input: n - number of pixels in the span
- * x, y - array of [n] pixels to stencil
+ * Apply stencil and depth testing to an array of pixels.
+ * This is used both for software and hardware stencil buffers.
+ *
+ * The comments in this function are a bit sparse but the code is
+ * almost identical to stencil_and_depth_test_span(), which is well
+ * commented.
+ *
+ * Input: n - number of pixels in the array
+ * x, y - array of [n] pixel positions
* z - array [n] of z values
- * Input: mask - array [n] of flags (1=test this pixel, 0=skip the pixel)
- * Output: mask - array [n] of flags (1=depth test passed, 0=failed)
+ * mask - array [n] of flags (1=test this pixel, 0=skip the pixel)
+ * Output: mask - array [n] of flags (1=stencil and depth test passed)
+ * Return: GL_TRUE - all fragments failed the testing
+ * GL_FALSE - one or more fragments passed the testing
*/
-void gl_depth_stencil_pixels( GLcontext *ctx,
- GLuint n, const GLint x[], const GLint y[],
- const GLdepth z[], GLubyte mask[] )
+GLboolean
+gl_stencil_and_depth_test_pixels( GLcontext *ctx,
+ GLuint n, const GLint x[], const GLint y[],
+ const GLdepth z[], GLubyte mask[] )
{
- if (ctx->Depth.Test==GL_FALSE) {
- /*
- * No depth buffer, just apply zpass stencil function to active pixels.
- */
- apply_stencil_op_to_pixels( ctx, n, x, y, ctx->Stencil.ZPassFunc, mask );
+ ASSERT(ctx->Stencil.Enabled);
+ ASSERT(n <= PB_SIZE);
+
+ if (ctx->Driver.WriteStencilPixels) {
+ /*** Hardware stencil buffer ***/
+ GLstencil stencil[PB_SIZE];
+ GLubyte mask[PB_SIZE];
+
+ ASSERT(ctx->Driver.ReadStencilPixels);
+ (*ctx->Driver.ReadStencilPixels)(ctx, n, x, y, stencil);
+
+
+ if (do_stencil_test( ctx, n, stencil, mask ) == GL_FALSE) {
+ /* all fragments failed the stencil test, we're done. */
+ return GL_FALSE;
+ }
+
+ if (ctx->Depth.Test == GL_FALSE) {
+ apply_stencil_op( ctx, ctx->Stencil.ZPassFunc, n, stencil, mask );
+ }
+ else {
+ GLubyte passmask[PB_SIZE], failmask[PB_SIZE], oldmask[PB_SIZE];
+ GLuint i;
+
+ MEMCPY(oldmask, mask, n * sizeof(GLubyte));
+
+ if (ctx->Driver.DepthTestPixels)
+ (*ctx->Driver.DepthTestPixels)( ctx, n, x, y, z, mask );
+
+ for (i=0;i<n;i++) {
+ ASSERT(mask[i] == 0 || mask[i] == 1);
+ passmask[i] = oldmask[i] & mask[i];
+ failmask[i] = oldmask[i] & (mask[i] ^ 1);
+ }
+
+ if (ctx->Stencil.ZFailFunc != GL_KEEP) {
+ apply_stencil_op( ctx, ctx->Stencil.ZFailFunc, n, stencil, failmask );
+ }
+ if (ctx->Stencil.ZPassFunc != GL_KEEP) {
+ apply_stencil_op( ctx, ctx->Stencil.ZPassFunc, n, stencil, passmask );
+ }
+ }
+
+ /* Write updated stencil values into hardware stencil buffer */
+ (ctx->Driver.WriteStencilPixels)(ctx, n, x, y, stencil, mask );
+
+ return GL_TRUE;
+
}
else {
- /*
- * Perform depth buffering, then apply zpass or zfail stencil function.
- */
- GLubyte passmask[PB_SIZE], failmask[PB_SIZE], oldmask[PB_SIZE];
- GLuint i;
+ /*** Software stencil buffer ***/
- /* save the current mask bits */
- MEMCPY(oldmask, mask, n * sizeof(GLubyte));
+ if (stencil_test_pixels(ctx, n, x, y, mask) == GL_FALSE) {
+ /* all fragments failed the stencil test, we're done. */
+ return GL_FALSE;
+ }
- /* apply the depth test */
- if (ctx->Driver.DepthTestPixels)
- (*ctx->Driver.DepthTestPixels)( ctx, n, x, y, z, mask );
- /* Set the stencil pass/fail flags according to result of depth testing.
- * if oldmask[i] == 0 then
- * Don't touch the stencil value
- * else if oldmask[i] and newmask[i] then
- * Depth test passed
- * else
- * assert(oldmask[i] && !newmask[i])
- * Depth test failed
- * endif
- */
- for (i=0;i<n;i++) {
- ASSERT(mask[i] == 0 || mask[i] == 1);
- passmask[i] = oldmask[i] & mask[i];
- failmask[i] = oldmask[i] & (mask[i] ^ 1);
+ if (ctx->Depth.Test==GL_FALSE) {
+ apply_stencil_op_to_pixels( ctx, n, x, y, ctx->Stencil.ZPassFunc, mask );
}
+ else {
+ GLubyte passmask[PB_SIZE], failmask[PB_SIZE], oldmask[PB_SIZE];
+ GLuint i;
- /* apply the pass and fail operations */
- apply_stencil_op_to_pixels( ctx, n, x, y,
- ctx->Stencil.ZFailFunc, failmask );
- apply_stencil_op_to_pixels( ctx, n, x, y,
- ctx->Stencil.ZPassFunc, passmask );
- }
+ MEMCPY(oldmask, mask, n * sizeof(GLubyte));
+ if (ctx->Driver.DepthTestPixels)
+ (*ctx->Driver.DepthTestPixels)( ctx, n, x, y, z, mask );
+
+ for (i=0;i<n;i++) {
+ ASSERT(mask[i] == 0 || mask[i] == 1);
+ passmask[i] = oldmask[i] & mask[i];
+ failmask[i] = oldmask[i] & (mask[i] ^ 1);
+ }
+
+ if (ctx->Stencil.ZFailFunc != GL_KEEP) {
+ apply_stencil_op_to_pixels( ctx, n, x, y,
+ ctx->Stencil.ZFailFunc, failmask );
+ }
+ if (ctx->Stencil.ZPassFunc != GL_KEEP) {
+ apply_stencil_op_to_pixels( ctx, n, x, y,
+ ctx->Stencil.ZPassFunc, passmask );
+ }
+ }
+
+ return GL_TRUE; /* one or more fragments passed both tests */
+ }
}
/*
* Return a span of stencil values from the stencil buffer.
+ * Used for glRead/CopyPixels
* Input: n - how many pixels
* x,y - location of first pixel
* Output: stencil - the array of stencil values
*/
void gl_read_stencil_span( GLcontext *ctx,
- GLuint n, GLint x, GLint y, GLstencil stencil[] )
+ GLint n, GLint x, GLint y, GLstencil stencil[] )
{
+ ASSERT(n >= 0);
if (ctx->DrawBuffer->Stencil) {
- const GLstencil *s = STENCIL_ADDRESS( x, y );
+ if (ctx->Driver.ReadStencilSpan) {
+ (*ctx->Driver.ReadStencilSpan)( ctx, (GLuint) n, x, y, stencil );
+ }
+ else {
+ const GLstencil *s = STENCIL_ADDRESS( x, y );
#if STENCIL_BITS == 8
- MEMCPY( stencil, s, n * sizeof(GLstencil) );
+ MEMCPY( stencil, s, n * sizeof(GLstencil) );
#else
- GLuint i;
- for (i=0;i<n;i++)
- stencil[i] = s[i];
+ GLuint i;
+ for (i=0;i<n;i++)
+ stencil[i] = s[i];
#endif
+ }
}
}
/*
* Write a span of stencil values to the stencil buffer.
+ * Used for glDraw/CopyPixels
* Input: n - how many pixels
- * x,y - location of first pixel
+ * x, y - location of first pixel
* stencil - the array of stencil values
*/
void gl_write_stencil_span( GLcontext *ctx,
- GLuint n, GLint x, GLint y,
+ GLint n, GLint x, GLint y,
const GLstencil stencil[] )
{
+ ASSERT(n >= 0);
if (ctx->DrawBuffer->Stencil) {
- GLstencil *s = STENCIL_ADDRESS( x, y );
+ /* do clipping */
+ if (y < ctx->DrawBuffer->Ymin || y > ctx->DrawBuffer->Ymax)
+ return;
+ if (x < ctx->DrawBuffer->Xmin) {
+ GLint diff = ctx->DrawBuffer->Xmin - x;
+ n -= diff;
+ stencil += diff;
+ x = ctx->DrawBuffer->Xmin;
+ }
+ if (x + n > ctx->DrawBuffer->Xmax) {
+ GLint diff = x + n - ctx->DrawBuffer->Xmax;
+ n -= diff;
+ }
+
+ ASSERT( n >= 0);
+
+ if (ctx->Driver.WriteStencilSpan) {
+ (*ctx->Driver.WriteStencilSpan)( ctx, n, x, y, stencil, NULL );
+ }
+ else {
+ GLstencil *s = STENCIL_ADDRESS( x, y );
#if STENCIL_BITS == 8
- MEMCPY( s, stencil, n * sizeof(GLstencil) );
+ MEMCPY( s, stencil, n * sizeof(GLstencil) );
#else
- GLuint i;
- for (i=0;i<n;i++)
- s[i] = stencil[i];
+ GLuint i;
+ for (i=0;i<n;i++)
+ s[i] = stencil[i];
#endif
+ }
}
}
-
-void gl_clear_stencil_buffer( GLcontext *ctx )
+/*
+ * Clear the software (malloc'd) stencil buffer.
+ */
+static void
+clear_software_stencil_buffer( GLcontext *ctx )
{
if (ctx->Visual->StencilBits==0 || !ctx->DrawBuffer->Stencil) {
/* no stencil buffer */
if (ctx->Stencil.WriteMask != STENCIL_MAX) {
/* must apply mask to the clear */
GLint y;
- for (y=ctx->DrawBuffer->Ymin; y<=ctx->DrawBuffer->Ymax; y++) {
- GLstencil *ptr = STENCIL_ADDRESS( ctx->DrawBuffer->Xmin, y );
- GLint x;
+ for (y = ctx->DrawBuffer->Ymin; y <= ctx->DrawBuffer->Ymax; y++) {
const GLstencil mask = ctx->Stencil.WriteMask;
const GLstencil invMask = ~mask;
const GLstencil clearVal = (ctx->Stencil.Clear & mask);
- for (x = 0; x < width; x++) {
- ptr[x] = (ptr[x] & invMask) | clearVal;
+ GLstencil *stencil = STENCIL_ADDRESS( ctx->DrawBuffer->Xmin, y );
+ GLint i;
+ for (i = 0; i < width; i++) {
+ stencil[i] = (stencil[i] & invMask) | clearVal;
}
}
}
else {
/* no masking */
GLint y;
- for (y=ctx->DrawBuffer->Ymin; y<=ctx->DrawBuffer->Ymax; y++) {
- GLstencil *ptr = STENCIL_ADDRESS( ctx->DrawBuffer->Xmin, y );
+ for (y = ctx->DrawBuffer->Ymin; y <= ctx->DrawBuffer->Ymax; y++) {
+ GLstencil *stencil = STENCIL_ADDRESS( ctx->DrawBuffer->Xmin, y );
#if STENCIL_BITS==8
- MEMSET( ptr, ctx->Stencil.Clear, width * sizeof(GLstencil) );
+ MEMSET( stencil, ctx->Stencil.Clear, width * sizeof(GLstencil) );
#else
- GLint x;
- for (x = 0; x < width; x++)
- ptr[x] = ctx->Stencil.Clear;
+ GLint i;
+ for (i = 0; i < width; i++)
+ stencil[x] = ctx->Stencil.Clear;
#endif
}
}
if (ctx->Stencil.WriteMask != STENCIL_MAX) {
/* must apply mask to the clear */
const GLuint n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
- GLstencil *buffer = ctx->DrawBuffer->Stencil;
+ GLstencil *stencil = ctx->DrawBuffer->Stencil;
const GLstencil mask = ctx->Stencil.WriteMask;
const GLstencil invMask = ~mask;
const GLstencil clearVal = (ctx->Stencil.Clear & mask);
GLuint i;
for (i = 0; i < n; i++) {
- buffer[i] = (buffer[i] & invMask) | clearVal;
+ stencil[i] = (stencil[i] & invMask) | clearVal;
}
}
else {
/* clear whole buffer without masking */
const GLuint n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
- GLstencil *buffer = ctx->DrawBuffer->Stencil;
+ GLstencil *stencil = ctx->DrawBuffer->Stencil;
#if STENCIL_BITS==8
- MEMSET(buffer, ctx->Stencil.Clear, n * sizeof(GLstencil) );
+ MEMSET(stencil, ctx->Stencil.Clear, n * sizeof(GLstencil) );
#else
GLuint i;
for (i = 0; i < n; i++) {
- buffer[i] = ctx->Stencil.Clear;
+ stencil[i] = ctx->Stencil.Clear;
}
#endif
}
}
}
+
+
+
+/*
+ * Clear the hardware (in graphics card) stencil buffer.
+ * This is done with the Driver.WriteStencilSpan() and Driver.ReadStencilSpan()
+ * functions.
+ * Actually, if there is a hardware stencil buffer it really should have
+ * been cleared in Driver.Clear()! However, if the hardware does not
+ * support scissored clears or masked clears (i.e. glStencilMask) then
+ * we have to use the span-based functions.
+ */
+static void
+clear_hardware_stencil_buffer( GLcontext *ctx )
+{
+ ASSERT(ctx->Driver.WriteStencilSpan);
+ ASSERT(ctx->Driver.ReadStencilSpan);
+
+ if (ctx->Scissor.Enabled) {
+ /* clear scissor region only */
+ const GLint x = ctx->DrawBuffer->Xmin;
+ const GLint width = ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin + 1;
+ if (ctx->Stencil.WriteMask != STENCIL_MAX) {
+ /* must apply mask to the clear */
+ GLint y;
+ for (y = ctx->DrawBuffer->Ymin; y <= ctx->DrawBuffer->Ymax; y++) {
+ const GLstencil mask = ctx->Stencil.WriteMask;
+ const GLstencil invMask = ~mask;
+ const GLstencil clearVal = (ctx->Stencil.Clear & mask);
+ GLstencil stencil[MAX_WIDTH];
+ GLint i;
+ (*ctx->Driver.ReadStencilSpan)(ctx, x, y, width, stencil);
+ for (i = 0; i < width; i++) {
+ stencil[i] = (stencil[i] & invMask) | clearVal;
+ }
+ (*ctx->Driver.WriteStencilSpan)(ctx, x, y, width, stencil, NULL);
+ }
+ }
+ else {
+ /* no masking */
+ GLstencil stencil[MAX_WIDTH];
+ GLint y, i;
+ for (i = 0; i < width; i++) {
+ stencil[i] = ctx->Stencil.Clear;
+ }
+ for (y = ctx->DrawBuffer->Ymin; y <= ctx->DrawBuffer->Ymax; y++) {
+ (*ctx->Driver.WriteStencilSpan)(ctx, x, y, width, stencil, NULL);
+ }
+ }
+ }
+ else {
+ /* clear whole stencil buffer */
+ if (ctx->Stencil.WriteMask != STENCIL_MAX) {
+ /* must apply mask to the clear */
+ const GLstencil mask = ctx->Stencil.WriteMask;
+ const GLstencil invMask = ~mask;
+ const GLstencil clearVal = (ctx->Stencil.Clear & mask);
+ const GLint width = ctx->DrawBuffer->Width;
+ const GLint height = ctx->DrawBuffer->Height;
+ const GLint x = ctx->DrawBuffer->Xmin;
+ GLint y;
+ for (y = 0; y < height; y++) {
+ GLstencil stencil[MAX_WIDTH];
+ GLuint i;
+ (*ctx->Driver.ReadStencilSpan)(ctx, x, y, width, stencil);
+ for (i = 0; i < width; i++) {
+ stencil[i] = (stencil[i] & invMask) | clearVal;
+ }
+ (*ctx->Driver.WriteStencilSpan)(ctx, x, y, width, stencil, NULL);
+ }
+ }
+ else {
+ /* clear whole buffer without masking */
+ const GLint width = ctx->DrawBuffer->Width;
+ const GLint height = ctx->DrawBuffer->Width;
+ const GLint x = ctx->DrawBuffer->Xmin;
+ GLstencil stencil[MAX_WIDTH];
+ GLint y, i;
+ for (i = 0; i < width; i++) {
+ stencil[i] = ctx->Stencil.Clear;
+ }
+ for (y = 0; y < height; y++) {
+ (*ctx->Driver.WriteStencilSpan)(ctx, x, y, width, stencil, NULL);
+ }
+ }
+ }
+}
+
+
+
+/*
+ * Clear the stencil buffer.
+ */
+void gl_clear_stencil_buffer( GLcontext *ctx )
+{
+ if (ctx->Driver.WriteStencilSpan) {
+ ASSERT(ctx->Driver.ReadStencilSpan);
+ clear_hardware_stencil_buffer(ctx);
+ }
+ else {
+ clear_software_stencil_buffer(ctx);
+ }
+}
+
projects / mesa.git / commitdiff