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GPU/Rasterizer: Corrected the stencil implementation.

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Verified the behavior with hardware tests.
This commit is contained in:
Subv 2015-08-20 10:10:35 -05:00
parent ef7eb8bc4c
commit 186873420f
2 changed files with 39 additions and 18 deletions
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20
src/video_core/pica.h
View file

@ -441,8 +441,12 @@ struct Regs {
};
enum class StencilAction : u32 {
Keep = 0,
Xor = 5,
Keep = 0,
Replace = 2,
Increment = 3,
Decrement = 4,
Invert = 5
};
struct {
@ -481,23 +485,29 @@ struct Regs {
struct {
union {
// Raw value of this register
u32 raw_func;
// If true, enable stencil testing
BitField< 0, 1, u32> enable;
// Comparison operation for stencil testing
BitField< 4, 3, CompareFunc> func;
// Value to calculate the new stencil value from
BitField< 8, 8, u32> replacement_value;
// Mask used to control writing to the stencil buffer
BitField< 8, 8, u32> write_mask;
// Value to compare against for stencil testing
BitField<16, 8, u32> reference_value;
// Mask to apply on stencil test inputs
BitField<24, 8, u32> mask;
BitField<24, 8, u32> input_mask;
};
union {
// Raw value of this register
u32 raw_op;
// Action to perform when the stencil test fails
BitField< 0, 3, StencilAction> action_stencil_fail;

37
src/video_core/rasterizer.cpp
View file

@ -215,14 +215,25 @@ static void SetStencil(int x, int y, u8 value) {
}
}
// TODO: Should the stencil mask be applied to the "dest" or "ref" operands? Most likely not!
static u8 PerformStencilAction(Regs::StencilAction action, u8 dest, u8 ref) {
// TODO: Should the stencil mask be applied to the "old_stencil" or "ref" operands? Most likely not!
static u8 PerformStencilAction(Regs::StencilAction action, u8 old_stencil, u8 ref) {
switch (action) {
case Regs::StencilAction::Keep:
return dest;
return old_stencil;
case Regs::StencilAction::Xor:
return dest ^ ref;
case Regs::StencilAction::Replace:
return ref;
case Regs::StencilAction::Increment:
// Saturated increment
return std::min<u8>(old_stencil, 254) + 1;
case Regs::StencilAction::Decrement:
// Saturated decrement
return std::max<u8>(old_stencil, 1) - 1;
case Regs::StencilAction::Invert:
return ~old_stencil;
default:
LOG_CRITICAL(HW_GPU, "Unknown stencil action %x", (int)action);
@ -782,8 +793,8 @@ static void ProcessTriangleInternal(const Shader::OutputVertex& v0,
u8 old_stencil = 0;
if (stencil_action_enable) {
old_stencil = GetStencil(x >> 4, y >> 4);
u8 dest = old_stencil & stencil_test.mask;
u8 ref = stencil_test.reference_value & stencil_test.mask;
u8 dest = old_stencil & stencil_test.input_mask;
u8 ref = stencil_test.reference_value & stencil_test.input_mask;
bool pass = false;
switch (stencil_test.func) {
@ -821,8 +832,8 @@ static void ProcessTriangleInternal(const Shader::OutputVertex& v0,
}
if (!pass) {
u8 new_stencil = PerformStencilAction(stencil_test.action_stencil_fail, old_stencil, stencil_test.replacement_value);
SetStencil(x >> 4, y >> 4, new_stencil);
u8 new_stencil = PerformStencilAction(stencil_test.action_stencil_fail, old_stencil, stencil_test.reference_value);
SetStencil(x >> 4, y >> 4, (new_stencil & stencil_test.write_mask) | (old_stencil & ~stencil_test.write_mask));
continue;
}
}
@ -873,8 +884,8 @@ static void ProcessTriangleInternal(const Shader::OutputVertex& v0,
if (!pass) {
if (stencil_action_enable) {
u8 new_stencil = PerformStencilAction(stencil_test.action_depth_fail, old_stencil, stencil_test.replacement_value);
SetStencil(x >> 4, y >> 4, new_stencil);
u8 new_stencil = PerformStencilAction(stencil_test.action_depth_fail, old_stencil, stencil_test.reference_value);
SetStencil(x >> 4, y >> 4, (new_stencil & stencil_test.write_mask) | (old_stencil & ~stencil_test.write_mask));
}
continue;
}
@ -884,8 +895,8 @@ static void ProcessTriangleInternal(const Shader::OutputVertex& v0,
if (stencil_action_enable) {
// TODO: What happens if stencil testing is enabled, but depth testing is not? Will stencil get updated anyway?
u8 new_stencil = PerformStencilAction(stencil_test.action_depth_pass, old_stencil, stencil_test.replacement_value);
SetStencil(x >> 4, y >> 4, new_stencil);
u8 new_stencil = PerformStencilAction(stencil_test.action_depth_pass, old_stencil, stencil_test.reference_value);
SetStencil(x >> 4, y >> 4, (new_stencil & stencil_test.write_mask) | (old_stencil & ~stencil_test.write_mask));
}
}