/*
* 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
* 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)
*/
void gl_depth_stencil_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;
/* init pass and fail masks to zero */
for (i=0;i<n;i++) {
passmask[i] = failmask[i] = 0;
oldmask[i] = mask[i];
}
/* 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 test */
for (i=0;i<n;i++) {
if (oldmask[i]) {
if (mask[i]) {
passmask[i] = 1;
}
else {
failmask[i] = 1;
}
}
}
/* 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 );
}
}
/*
* 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
* 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.
*/
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;
GLboolean allfail = GL_FALSE;
ASSERT(!ctx->Driver.WriteStencilSpan); /* software stencil buffer only! */
/*
* Perform stencil test. The results of this operation are stored
* in the fail[] array:
* IF fail[i] is non-zero THEN
* the stencil fail operator is to be applied
* ELSE
* the stencil fail operator is not to be applied
* ENDIF
*/
switch (ctx->Stencil.Function) {
case GL_NEVER:
/* always fail */
for (i=0;i<n;i++) {
if (mask[i]) {
mask[i] = 0;
fail[i] = 1;
}
else {
fail[i] = 0;
}
}
allfail = GL_TRUE;
break;
case GL_LESS:
r = (GLstencil) (ctx->Stencil.Ref & ctx->Stencil.ValueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & ctx->Stencil.ValueMask);
if (r < s) {
/* passed */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_LEQUAL:
r = (GLstencil) (ctx->Stencil.Ref & ctx->Stencil.ValueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & ctx->Stencil.ValueMask);
if (r <= s) {
/* pass */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_GREATER:
r = (GLstencil) (ctx->Stencil.Ref & ctx->Stencil.ValueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & ctx->Stencil.ValueMask);
if (r > s) {
/* passed */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_GEQUAL:
r = (GLstencil) (ctx->Stencil.Ref & ctx->Stencil.ValueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & ctx->Stencil.ValueMask);
if (r >= s) {
/* passed */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_EQUAL:
r = (GLstencil) (ctx->Stencil.Ref & ctx->Stencil.ValueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & ctx->Stencil.ValueMask);
if (r == s) {
/* passed */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_NOTEQUAL:
r = (GLstencil) (ctx->Stencil.Ref & ctx->Stencil.ValueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & ctx->Stencil.ValueMask);
if (r != s) {
/* passed */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_ALWAYS:
/* always pass */
for (i=0;i<n;i++) {
fail[i] = 0;
}
break;
default:
gl_problem(ctx, "Bad stencil func in gl_stencil_pixels");
return 0;
}
if (ctx->Stencil.FailFunc != GL_KEEP) {
apply_stencil_op_to_pixels( ctx, n, x, y, ctx->Stencil.FailFunc, fail );
}
return !allfail;
}
/*
* 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_ztest_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
* 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
_mesa_stencil_and_ztest_pixels( GLcontext *ctx,
GLuint n, const GLint x[], const GLint y[],
const GLdepth z[], GLubyte mask[] )
{
ASSERT(ctx->Stencil.Enabled);
ASSERT(n <= PB_SIZE);
if (ctx->Driver.WriteStencilPixels) {
/*** Hardware stencil buffer ***/
GLstencil stencil[PB_SIZE];
GLubyte origMask[PB_SIZE];
ASSERT(ctx->Driver.ReadStencilPixels);
(*ctx->Driver.ReadStencilPixels)(ctx, n, x, y, stencil);
MEMCPY(origMask, mask, n * sizeof(GLubyte));
(void) do_stencil_test( ctx, n, stencil, mask );
if (ctx->Depth.Test == GL_FALSE) {
apply_stencil_op( ctx, ctx->Stencil.ZPassFunc, n, stencil, mask );
}
else {
_mesa_depth_test_pixels(ctx, n, x, y, z, mask);
if (ctx->Stencil.ZFailFunc != GL_KEEP) {
GLubyte failmask[PB_SIZE];
GLuint i;
for (i = 0; i < n; i++) {
ASSERT(mask[i] == 0 || mask[i] == 1);
failmask[i] = origMask[i] & (mask[i] ^ 1);
}
apply_stencil_op(ctx, ctx->Stencil.ZFailFunc, n, stencil, failmask);
}
if (ctx->Stencil.ZPassFunc != GL_KEEP) {
GLubyte passmask[PB_SIZE];
GLuint i;
for (i = 0; i < n; i++) {
ASSERT(mask[i] == 0 || mask[i] == 1);
passmask[i] = origMask[i] & mask[i];
}
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, origMask );
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));
_mesa_depth_test_pixels(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 */
}
}
/**
* 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_ztest_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
* 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_FALSE - all fragments failed the testing
* GL_TRUE - one or more fragments passed the testing
*/
static GLboolean
stencil_and_ztest_pixels( GLcontext *ctx, struct sw_span *span, GLuint face )
{
const GLuint n = span->end;
const GLint *x = span->array->x;
const GLint *y = span->array->y;
GLubyte *mask = span->array->mask;
SWcontext *swrast = SWRAST_CONTEXT(ctx);
ASSERT(span->arrayMask & SPAN_XY);
ASSERT(ctx->Stencil.Enabled);
ASSERT(n <= MAX_WIDTH);
if (swrast->Driver.WriteStencilPixels) {
/*** Hardware stencil buffer ***/
GLstencil stencil[MAX_WIDTH];
GLubyte origMask[MAX_WIDTH];
ASSERT(!ctx->DrawBuffer->UseSoftwareStencilBuffer);
ASSERT(swrast->Driver.ReadStencilPixels);
(*swrast->Driver.ReadStencilPixels)(ctx, n, x, y, stencil);
MEMCPY(origMask, mask, n * sizeof(GLubyte));
(void) do_stencil_test(ctx, face, n, stencil, mask);
if (ctx->Depth.Test == GL_FALSE) {
apply_stencil_op(ctx, ctx->Stencil.ZPassFunc[face], face,
n, stencil, mask);
}
else {
_swrast_depth_test_span(ctx, span);
if (ctx->Stencil.ZFailFunc[face] != GL_KEEP) {
GLubyte failmask[MAX_WIDTH];
GLuint i;
for (i = 0; i < n; i++) {
ASSERT(mask[i] == 0 || mask[i] == 1);
failmask[i] = origMask[i] & (mask[i] ^ 1);
}
apply_stencil_op(ctx, ctx->Stencil.ZFailFunc[face], face,
n, stencil, failmask);
}
if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {
GLubyte passmask[MAX_WIDTH];
GLuint i;
for (i = 0; i < n; i++) {
ASSERT(mask[i] == 0 || mask[i] == 1);
passmask[i] = origMask[i] & mask[i];
}
apply_stencil_op(ctx, ctx->Stencil.ZPassFunc[face], face,
n, stencil, passmask);
}
}
/* Write updated stencil values into hardware stencil buffer */
(swrast->Driver.WriteStencilPixels)(ctx, n, x, y, stencil, origMask);
return GL_TRUE;
}
else {
/*** Software stencil buffer ***/
ASSERT(ctx->DrawBuffer->UseSoftwareStencilBuffer);
if (stencil_test_pixels(ctx, face, 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[face], face, mask);
}
else {
GLubyte passmask[MAX_WIDTH], failmask[MAX_WIDTH], oldmask[MAX_WIDTH];
GLuint i;
MEMCPY(oldmask, mask, n * sizeof(GLubyte));
_swrast_depth_test_span(ctx, span);
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[face] != GL_KEEP) {
apply_stencil_op_to_pixels(ctx, n, x, y,
ctx->Stencil.ZFailFunc[face],
face, failmask);
}
if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {
apply_stencil_op_to_pixels(ctx, n, x, y,
ctx->Stencil.ZPassFunc[face],
face, passmask);
}
}
return GL_TRUE; /* one or more fragments passed both tests */
}
}
/**
* 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_ztest_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
* 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_FALSE - all fragments failed the testing
* GL_TRUE - one or more fragments passed the testing
*/
static GLboolean
stencil_and_ztest_pixels( GLcontext *ctx, SWspan *span, GLuint face )
{
struct gl_framebuffer *fb = ctx->DrawBuffer;
struct gl_renderbuffer *rb = fb->_StencilBuffer;
const GLuint n = span->end;
const GLint *x = span->array->x;
const GLint *y = span->array->y;
GLubyte *mask = span->array->mask;
ASSERT(span->arrayMask & SPAN_XY);
ASSERT(ctx->Stencil.Enabled);
ASSERT(n <= MAX_WIDTH);
if (!rb->GetPointer(ctx, rb, 0, 0)) {
/* No direct access */
GLstencil stencil[MAX_WIDTH];
GLubyte origMask[MAX_WIDTH];
ASSERT(rb->DataType == GL_UNSIGNED_BYTE);
_swrast_get_values(ctx, rb, n, x, y, stencil, sizeof(GLubyte));
_mesa_memcpy(origMask, mask, n * sizeof(GLubyte));
(void) do_stencil_test(ctx, face, n, stencil, mask);
if (ctx->Depth.Test == GL_FALSE) {
apply_stencil_op(ctx, ctx->Stencil.ZPassFunc[face], face,
n, stencil, mask);
}
else {
_swrast_depth_test_span(ctx, span);
if (ctx->Stencil.ZFailFunc[face] != GL_KEEP) {
GLubyte failmask[MAX_WIDTH];
GLuint i;
for (i = 0; i < n; i++) {
ASSERT(mask[i] == 0 || mask[i] == 1);
failmask[i] = origMask[i] & (mask[i] ^ 1);
}
apply_stencil_op(ctx, ctx->Stencil.ZFailFunc[face], face,
n, stencil, failmask);
}
if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {
GLubyte passmask[MAX_WIDTH];
GLuint i;
for (i = 0; i < n; i++) {
ASSERT(mask[i] == 0 || mask[i] == 1);
passmask[i] = origMask[i] & mask[i];
}
apply_stencil_op(ctx, ctx->Stencil.ZPassFunc[face], face,
n, stencil, passmask);
}
}
/* Write updated stencil values into hardware stencil buffer */
rb->PutValues(ctx, rb, n, x, y, stencil, origMask);
return GL_TRUE;
}
else {
/* Direct access to stencil buffer */
if (stencil_test_pixels(ctx, face, 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[face], face, mask);
}
else {
GLubyte passmask[MAX_WIDTH], failmask[MAX_WIDTH], oldmask[MAX_WIDTH];
GLuint i;
_mesa_memcpy(oldmask, mask, n * sizeof(GLubyte));
_swrast_depth_test_span(ctx, span);
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[face] != GL_KEEP) {
apply_stencil_op_to_pixels(ctx, n, x, y,
ctx->Stencil.ZFailFunc[face],
face, failmask);
}
if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {
apply_stencil_op_to_pixels(ctx, n, x, y,
ctx->Stencil.ZPassFunc[face],
face, passmask);
}
}
return GL_TRUE; /* one or more fragments passed both tests */
}
}
/**
* Apply stencil test to an array of pixels before depth buffering.
*
* \note 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
* Output: mask - pixels which fail the stencil test will have their
* mask flag set to 0.
* \return GL_FALSE = all pixels failed, GL_TRUE = zero or more pixels passed.
*/
static GLboolean
stencil_test_pixels( GLcontext *ctx, GLuint face, GLuint n,
const GLint x[], const GLint y[], GLubyte mask[] )
{
const struct gl_framebuffer *fb = ctx->DrawBuffer;
struct gl_renderbuffer *rb = fb->_StencilBuffer;
GLubyte fail[MAX_WIDTH];
GLstencil r, s;
GLuint i;
GLboolean allfail = GL_FALSE;
const GLuint valueMask = ctx->Stencil.ValueMask[face];
const GLstencil *stencilStart = (GLstencil *) rb->Data;
const GLuint stride = rb->Width;
ASSERT(rb->GetPointer(ctx, rb, 0, 0));
ASSERT(sizeof(GLstencil) == 1);
/*
* Perform stencil test. The results of this operation are stored
* in the fail[] array:
* IF fail[i] is non-zero THEN
* the stencil fail operator is to be applied
* ELSE
* the stencil fail operator is not to be applied
* ENDIF
*/
switch (ctx->Stencil.Function[face]) {
case GL_NEVER:
/* always fail */
for (i=0;i<n;i++) {
if (mask[i]) {
mask[i] = 0;
fail[i] = 1;
}
else {
fail[i] = 0;
}
}
allfail = GL_TRUE;
break;
case GL_LESS:
r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & valueMask);
if (r < s) {
/* passed */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_LEQUAL:
r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & valueMask);
if (r <= s) {
/* pass */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_GREATER:
r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & valueMask);
if (r > s) {
/* passed */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_GEQUAL:
r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & valueMask);
if (r >= s) {
/* passed */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_EQUAL:
r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & valueMask);
if (r == s) {
/* passed */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_NOTEQUAL:
r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
for (i=0;i<n;i++) {
if (mask[i]) {
const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
s = (GLstencil) (*sptr & valueMask);
if (r != s) {
/* passed */
fail[i] = 0;
}
else {
fail[i] = 1;
mask[i] = 0;
}
}
else {
fail[i] = 0;
}
}
break;
case GL_ALWAYS:
/* always pass */
for (i=0;i<n;i++) {
fail[i] = 0;
}
break;
default:
_mesa_problem(ctx, "Bad stencil func in gl_stencil_pixels");
return 0;
}
if (ctx->Stencil.FailFunc[face] != GL_KEEP) {
apply_stencil_op_to_pixels( ctx, n, x, y, ctx->Stencil.FailFunc[face],
face, fail );
}
return !allfail;
}
