/**
* Do the one or two-sided stencil test comparison.
* \sa lp_build_stencil_test_single
* \param front_facing an integer vector mask, indicating front (~0) or back
* (0) facing polygon. If NULL, assume front-facing.
*/
static LLVMValueRef
lp_build_stencil_test(struct lp_build_context *bld,
const struct pipe_stencil_state stencil[2],
LLVMValueRef stencilRefs[2],
LLVMValueRef stencilVals,
LLVMValueRef front_facing)
{
LLVMValueRef res;
assert(stencil[0].enabled);
/* do front face test */
res = lp_build_stencil_test_single(bld, &stencil[0],
stencilRefs[0], stencilVals);
if (stencil[1].enabled && front_facing != NULL) {
/* do back face test */
LLVMValueRef back_res;
back_res = lp_build_stencil_test_single(bld, &stencil[1],
stencilRefs[1], stencilVals);
res = lp_build_select(bld, front_facing, res, back_res);
}
return res;
}
/**
* Do the one or two-sided stencil test comparison.
* \sa lp_build_stencil_test_single
* \param face an integer indicating front (+) or back (-) facing polygon.
* If NULL, assume front-facing.
*/
static LLVMValueRef
lp_build_stencil_test(struct lp_build_context *bld,
const struct pipe_stencil_state stencil[2],
LLVMValueRef stencilRefs[2],
LLVMValueRef stencilVals,
LLVMValueRef face)
{
LLVMValueRef res;
assert(stencil[0].enabled);
if (stencil[1].enabled && face) {
/* do two-sided test */
struct lp_build_flow_context *flow_ctx;
struct lp_build_if_state if_ctx;
LLVMValueRef front_facing;
LLVMValueRef zero = LLVMConstReal(LLVMFloatType(), 0.0);
LLVMValueRef result = bld->undef;
flow_ctx = lp_build_flow_create(bld->builder);
lp_build_flow_scope_begin(flow_ctx);
lp_build_flow_scope_declare(flow_ctx, &result);
/* front_facing = face > 0.0 */
front_facing = LLVMBuildFCmp(bld->builder, LLVMRealUGT, face, zero, "");
lp_build_if(&if_ctx, flow_ctx, bld->builder, front_facing);
{
result = lp_build_stencil_test_single(bld, &stencil[0],
stencilRefs[0], stencilVals);
}
lp_build_else(&if_ctx);
{
result = lp_build_stencil_test_single(bld, &stencil[1],
stencilRefs[1], stencilVals);
}
lp_build_endif(&if_ctx);
lp_build_flow_scope_end(flow_ctx);
lp_build_flow_destroy(flow_ctx);
res = result;
}
else {
/* do single-side test */
res = lp_build_stencil_test_single(bld, &stencil[0],
stencilRefs[0], stencilVals);
}
return res;
}
