/*
* 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
_mesa_stencil_and_ztest_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_ztest_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;
}
/**
* /return GL_TRUE = one or more fragments passed,
* GL_FALSE = all fragments failed.
*/
GLboolean
_swrast_stencil_and_ztest_span(GLcontext *ctx, SWspan *span)
{
if (span->arrayMask & SPAN_XY)
return stencil_and_ztest_pixels(ctx, span, span->facing);
else
return stencil_and_ztest_span(ctx, span, span->facing);
}
/**
* /return GL_TRUE = one or more fragments passed,
* GL_FALSE = all fragments failed.
*/
GLboolean
_swrast_stencil_and_ztest_span(GLcontext *ctx, struct sw_span *span)
{
/* span->facing can only be non-zero if using two-sided stencil */
ASSERT(ctx->Stencil.TestTwoSide || span->facing == 0);
if (span->arrayMask & SPAN_XY)
return stencil_and_ztest_pixels(ctx, span, span->facing);
else
return stencil_and_ztest_span(ctx, span, span->facing);
}
/**
* /return GL_TRUE = one or more fragments passed,
* GL_FALSE = all fragments failed.
*/
GLboolean
_swrast_stencil_and_ztest_span(struct gl_context *ctx, SWspan *span)
{
const GLuint face = (span->facing == 0) ? 0 : ctx->Stencil._BackFace;
if (span->arrayMask & SPAN_XY)
return stencil_and_ztest_pixels(ctx, span, face);
else
return stencil_and_ztest_span(ctx, span, face);
}