/**
* 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( struct gl_context *ctx, SWspan *span, GLuint face )
{
GLubyte passMask[MAX_WIDTH], failMask[MAX_WIDTH], origMask[MAX_WIDTH];
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 */
GLubyte stencil[MAX_WIDTH];
ASSERT(rb->DataType == GL_UNSIGNED_BYTE);
_swrast_get_values(ctx, rb, n, x, y, stencil, sizeof(GLubyte));
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 {
GLubyte tmpMask[MAX_WIDTH];
memcpy(tmpMask, mask, n * sizeof(GLubyte));
_swrast_depth_test_span(ctx, span);
compute_pass_fail_masks(n, tmpMask, mask, passMask, failMask);
if (ctx->Stencil.ZFailFunc[face] != GL_KEEP) {
apply_stencil_op(ctx, ctx->Stencil.ZFailFunc[face], face,
n, stencil, failMask);
}
if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {
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 {
memcpy(origMask, mask, n * sizeof(GLubyte));
_swrast_depth_test_span(ctx, span);
compute_pass_fail_masks(n, origMask, mask, passMask, failMask);
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 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_FALSE - all fragments failed the testing
* GL_TRUE - one or more fragments passed the testing
*
*/
static GLboolean
stencil_and_ztest_span(GLcontext *ctx, SWspan *span, GLuint face)
{
struct gl_framebuffer *fb = ctx->DrawBuffer;
struct gl_renderbuffer *rb = fb->_StencilBuffer;
GLstencil stencilRow[MAX_WIDTH];
GLstencil *stencil;
const GLuint n = span->end;
const GLint x = span->x;
const GLint y = span->y;
GLubyte *mask = span->array->mask;
ASSERT((span->arrayMask & SPAN_XY) == 0);
ASSERT(ctx->Stencil.Enabled);
ASSERT(n <= MAX_WIDTH);
#ifdef DEBUG
if (ctx->Depth.Test) {
ASSERT(span->arrayMask & SPAN_Z);
}
#endif
stencil = (GLstencil *) rb->GetPointer(ctx, rb, x, y);
if (!stencil) {
rb->GetRow(ctx, rb, n, x, y, stencilRow);
stencil = stencilRow;
}
/*
* Apply the stencil test to the fragments.
* failMask[i] is 1 if the stencil test failed.
*/
if (do_stencil_test( ctx, face, n, stencil, mask ) == GL_FALSE) {
/* all fragments failed the stencil test, we're done. */
span->writeAll = GL_FALSE;
if (!rb->GetPointer(ctx, rb, 0, 0)) {
/* put updated stencil values into buffer */
rb->PutRow(ctx, rb, n, x, y, stencil, NULL);
}
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[face], face, n, stencil, mask );
}
else {
/*
* Perform depth buffering, then apply zpass or zfail stencil function.
*/
GLubyte passmask[MAX_WIDTH], failmask[MAX_WIDTH], oldmask[MAX_WIDTH];
GLuint i;
/* save the current mask bits */
_mesa_memcpy(oldmask, mask, n * sizeof(GLubyte));
/* apply the depth test */
_swrast_depth_test_span(ctx, span);
/* 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);
}
/* apply the pass and fail operations */
if (ctx->Stencil.ZFailFunc[face] != GL_KEEP) {
apply_stencil_op( ctx, ctx->Stencil.ZFailFunc[face], face,
n, stencil, failmask );
}
if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {
apply_stencil_op( ctx, ctx->Stencil.ZPassFunc[face], face,
n, stencil, passmask );
}
}
/*
* Write updated stencil values back into hardware stencil buffer.
*/
if (!rb->GetPointer(ctx, rb, 0, 0)) {
rb->PutRow(ctx, rb, n, x, y, stencil, NULL);
}
span->writeAll = GL_FALSE;
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_FALSE - all fragments failed the testing
* GL_TRUE - one or more fragments passed the testing
*
*/
static GLboolean
stencil_and_ztest_span(struct gl_context *ctx, SWspan *span, GLuint face)
{
struct gl_framebuffer *fb = ctx->DrawBuffer;
struct gl_renderbuffer *rb = fb->_StencilBuffer;
GLubyte stencilRow[MAX_WIDTH];
GLubyte *stencil;
const GLuint n = span->end;
const GLint x = span->x;
const GLint y = span->y;
GLubyte *mask = span->array->mask;
ASSERT((span->arrayMask & SPAN_XY) == 0);
ASSERT(ctx->Stencil.Enabled);
ASSERT(n <= MAX_WIDTH);
#ifdef DEBUG
if (ctx->Depth.Test) {
ASSERT(span->arrayMask & SPAN_Z);
}
#endif
stencil = (GLubyte *) rb->GetPointer(ctx, rb, x, y);
if (!stencil) {
rb->GetRow(ctx, rb, n, x, y, stencilRow);
stencil = stencilRow;
}
/*
* Apply the stencil test to the fragments.
* failMask[i] is 1 if the stencil test failed.
*/
if (do_stencil_test( ctx, face, n, stencil, mask ) == GL_FALSE) {
/* all fragments failed the stencil test, we're done. */
span->writeAll = GL_FALSE;
if (!rb->GetPointer(ctx, rb, 0, 0)) {
/* put updated stencil values into buffer */
rb->PutRow(ctx, rb, n, x, y, stencil, NULL);
}
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 ||
ctx->DrawBuffer->_DepthBuffer == NULL) {
/*
* No depth buffer, just apply zpass stencil function to active pixels.
*/
apply_stencil_op( ctx, ctx->Stencil.ZPassFunc[face], face, n, stencil, mask );
}
else {
/*
* Perform depth buffering, then apply zpass or zfail stencil function.
*/
GLubyte passMask[MAX_WIDTH], failMask[MAX_WIDTH], origMask[MAX_WIDTH];
/* save the current mask bits */
memcpy(origMask, mask, n * sizeof(GLubyte));
/* apply the depth test */
_swrast_depth_test_span(ctx, span);
compute_pass_fail_masks(n, origMask, mask, passMask, failMask);
/* apply the pass and fail operations */
if (ctx->Stencil.ZFailFunc[face] != GL_KEEP) {
apply_stencil_op( ctx, ctx->Stencil.ZFailFunc[face], face,
n, stencil, failMask );
}
if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {
apply_stencil_op( ctx, ctx->Stencil.ZPassFunc[face], face,
n, stencil, passMask );
}
}
/*
* Write updated stencil values back into hardware stencil buffer.
*/
if (!rb->GetPointer(ctx, rb, 0, 0)) {
rb->PutRow(ctx, rb, n, x, y, stencil, NULL);
}
span->writeAll = GL_FALSE;
return GL_TRUE; /* one or more fragments passed both tests */
}
