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updated for hardware stencil support

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This commit is contained in:
Brian Paul
1999-12-10 16:15:04 +00:00
parent 86d518ec5b
commit 5ee41bda2c
2 changed files with 403 additions and 142 deletions
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src/mesa/main/stencil.c
+388 -120
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@@ -1,4 +1,4 @@
/* $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
@@ -190,13 +190,15 @@ ENDIF
/*
* 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;
@@ -298,7 +300,7 @@ static void apply_stencil_op( GLcontext *ctx, GLenum oper,
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)));
}
}
}
@@ -315,7 +317,7 @@ static void apply_stencil_op( GLcontext *ctx, GLenum oper,
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)));
}
}
}
@@ -347,24 +349,25 @@ static void apply_stencil_op( GLcontext *ctx, GLenum oper,
/*
* 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
@@ -387,7 +390,7 @@ GLint gl_stencil_span( GLcontext *ctx,
fail[i] = 0;
}
}
allfail = 1;
allfail = GL_TRUE;
break;
case GL_LESS:
r = (GLstencil) (ctx->Stencil.Ref & ctx->Stencil.ValueMask);
@@ -518,26 +521,47 @@ GLint gl_stencil_span( GLcontext *ctx,
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.
@@ -582,6 +606,56 @@ void gl_depth_stencil_span( GLcontext *ctx,
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;
}
@@ -589,25 +663,23 @@ void gl_depth_stencil_span( GLcontext *ctx,
/*
* 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:
@@ -756,6 +828,7 @@ static void apply_stencil_op_to_pixels( GLcontext *ctx,
/*
* 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
@@ -763,14 +836,16 @@ static void apply_stencil_op_to_pixels( GLcontext *ctx,
* 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
@@ -794,7 +869,7 @@ GLint gl_stencil_pixels( GLcontext *ctx,
fail[i] = 0;
}
}
allfail = 1;
allfail = GL_TRUE;
break;
case GL_LESS:
r = (GLstencil) (ctx->Stencil.Ref & ctx->Stencil.ValueMask);
@@ -927,91 +1002,154 @@ GLint gl_stencil_pixels( GLcontext *ctx,
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 );
}
else {
/*
* Perform depth buffering, then apply zpass or zfail stencil function.
*/
GLubyte passmask[PB_SIZE], failmask[PB_SIZE], oldmask[PB_SIZE];
GLuint i;
ASSERT(ctx->Stencil.Enabled);
ASSERT(n <= PB_SIZE);
/* save the current mask bits */
MEMCPY(oldmask, mask, n * sizeof(GLubyte));
if (ctx->Driver.WriteStencilPixels) {
/*** Hardware stencil buffer ***/
GLstencil stencil[PB_SIZE];
GLubyte mask[PB_SIZE];
/* apply the depth test */
if (ctx->Driver.DepthTestPixels)
(*ctx->Driver.DepthTestPixels)( ctx, n, x, y, z, mask );
ASSERT(ctx->Driver.ReadStencilPixels);
(*ctx->Driver.ReadStencilPixels)(ctx, n, x, y, stencil);
/* 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 (do_stencil_test( ctx, n, stencil, mask ) == GL_FALSE) {
/* all fragments failed the stencil test, we're done. */
return GL_FALSE;
}
/* 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 );
}
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 {
/*** Software stencil buffer ***/
if (stencil_test_pixels(ctx, n, x, y, mask) == GL_FALSE) {
/* all fragments failed the stencil test, we're done. */
return GL_FALSE;
}
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;
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
}
}
}
@@ -1019,23 +1157,46 @@ void gl_read_stencil_span( GLcontext *ctx,
/*
* 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
}
}
}
@@ -1066,8 +1227,11 @@ void gl_alloc_stencil_buffer( GLcontext *ctx )
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 */
@@ -1080,28 +1244,28 @@ void gl_clear_stencil_buffer( GLcontext *ctx )
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
}
}
@@ -1111,28 +1275,132 @@ void gl_clear_stencil_buffer( GLcontext *ctx )
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);
}
}
src/mesa/main/stencil.h
+15 -22
View File
@@ -1,4 +1,4 @@
/* $Id: stencil.h,v 1.2 1999/11/11 01:22:27 brianp Exp $ */
/* $Id: stencil.h,v 1.3 1999/12/10 16:15:04 brianp Exp $ */
/*
* Mesa 3-D graphics library
@@ -49,33 +49,26 @@ _mesa_StencilOp( GLenum fail, GLenum zfail, GLenum zpass );
extern GLint gl_stencil_span( GLcontext *ctx,
GLuint n, GLint x, GLint y, GLubyte mask[] );
extern GLboolean
gl_stencil_and_depth_test_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
const GLdepth z[], GLubyte mask[] );
extern void gl_depth_stencil_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
const GLdepth z[], GLubyte mask[] );
extern GLboolean
gl_stencil_and_depth_test_pixels( GLcontext *ctx, GLuint n,
const GLint x[], const GLint y[],
const GLdepth z[], GLubyte mask[] );
extern GLint gl_stencil_pixels( GLcontext *ctx,
GLuint n, const GLint x[], const GLint y[],
GLubyte mask[] );
extern void
gl_read_stencil_span( GLcontext *ctx, GLint n, GLint x, GLint y,
GLstencil stencil[] );
extern void gl_depth_stencil_pixels( GLcontext *ctx,
GLuint n, const GLint x[],
const GLint y[], const GLdepth z[],
GLubyte mask[] );
extern void gl_read_stencil_span( GLcontext *ctx,
GLuint n, GLint x, GLint y,
GLstencil stencil[] );
extern void gl_write_stencil_span( GLcontext *ctx,
GLuint n, GLint x, GLint y,
const GLstencil stencil[] );
extern void
gl_write_stencil_span( GLcontext *ctx, GLint n, GLint x, GLint y,
const GLstencil stencil[] );
extern void gl_alloc_stencil_buffer( GLcontext *ctx );