Pica: Implement stencil testing.

This commit is contained in:
Tony Wasserka 2015-05-21 16:51:31 +02:00
parent 302e9a20f3
commit 5e79706db2
3 changed files with 199 additions and 13 deletions

View file

@ -208,7 +208,32 @@ inline void EncodeD24(u32 value, u8* bytes) {
* @param bytes Pointer where to store the encoded value
*/
inline void EncodeD24S8(u32 depth, u8 stencil, u8* bytes) {
*reinterpret_cast<u32_le*>(bytes) = (stencil << 24) | depth;
bytes[0] = depth & 0xFF;
bytes[1] = (depth >> 8) & 0xFF;
bytes[2] = (depth >> 16) & 0xFF;
bytes[3] = stencil;
}
/**
* Encode a 24 bit depth value as D24X8 format (32 bits per pixel with 8 bits unused)
* @param depth 24 bit source depth value to encode
* @param bytes Pointer where to store the encoded value
* @note unused bits will not be modified
*/
inline void EncodeD24X8(u32 depth, u8* bytes) {
bytes[0] = depth & 0xFF;
bytes[1] = (depth >> 8) & 0xFF;
bytes[2] = (depth >> 16) & 0xFF;
}
/**
* Encode an 8 bit stencil value as X24S8 format (32 bits per pixel with 24 bits unused)
* @param stencil 8 bit source stencil value to encode
* @param bytes Pointer where to store the encoded value
* @note unused bits will not be modified
*/
inline void EncodeX24S8(u8 stencil, u8* bytes) {
bytes[3] = stencil;
}
} // namespace

View file

@ -420,6 +420,11 @@ struct Regs {
GreaterThanOrEqual = 7,
};
enum class StencilAction : u32 {
Keep = 0,
Xor = 5,
};
struct {
union {
// If false, logic blending is used
@ -454,15 +459,35 @@ struct Regs {
BitField< 8, 8, u32> ref;
} alpha_test;
struct {
union {
BitField< 0, 1, u32> stencil_test_enable;
BitField< 4, 3, CompareFunc> stencil_test_func;
BitField< 8, 8, u32> stencil_replacement_value;
BitField<16, 8, u32> stencil_reference_value;
BitField<24, 8, u32> stencil_mask;
} stencil_test;
// If true, enable stencil testing
BitField< 0, 1, u32> enable;
INSERT_PADDING_WORDS(0x1);
// Comparison operation for stencil testing
BitField< 4, 3, CompareFunc> func;
// Value to calculate the new stencil value from
BitField< 8, 8, u32> replacement_value;
// 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;
};
union {
// Action to perform when the stencil test fails
BitField< 0, 3, StencilAction> action_stencil_fail;
// Action to perform when stencil testing passed but depth testing fails
BitField< 4, 3, StencilAction> action_depth_fail;
// Action to perform when both stencil and depth testing pass
BitField< 8, 3, StencilAction> action_depth_pass;
};
} stencil_test;
union {
BitField< 0, 1, u32> depth_test_enable;
@ -512,7 +537,7 @@ struct Regs {
struct {
INSERT_PADDING_WORDS(0x6);
DepthFormat depth_format;
DepthFormat depth_format; // TODO: Should be a BitField!
BitField<16, 3, ColorFormat> color_format;
INSERT_PADDING_WORDS(0x4);

View file

@ -126,6 +126,30 @@ static u32 GetDepth(int x, int y) {
}
}
static u8 GetStencil(int x, int y) {
const auto& framebuffer = g_state.regs.framebuffer;
const PAddr addr = framebuffer.GetDepthBufferPhysicalAddress();
u8* depth_buffer = Memory::GetPhysicalPointer(addr);
y = framebuffer.height - y;
const u32 coarse_y = y & ~7;
u32 bytes_per_pixel = Pica::Regs::BytesPerDepthPixel(framebuffer.depth_format);
u32 stride = framebuffer.width * bytes_per_pixel;
u32 src_offset = VideoCore::GetMortonOffset(x, y, bytes_per_pixel) + coarse_y * stride;
u8* src_pixel = depth_buffer + src_offset;
switch (framebuffer.depth_format) {
case Regs::DepthFormat::D24S8:
return Color::DecodeD24S8(src_pixel).y;
default:
LOG_WARNING(HW_GPU, "GetStencil called for function which doesn't have a stencil component (format %u)", framebuffer.depth_format);
return 0;
}
}
static void SetDepth(int x, int y, u32 value) {
const auto& framebuffer = g_state.regs.framebuffer;
const PAddr addr = framebuffer.GetDepthBufferPhysicalAddress();
@ -144,13 +168,15 @@ static void SetDepth(int x, int y, u32 value) {
case Regs::DepthFormat::D16:
Color::EncodeD16(value, dst_pixel);
break;
case Regs::DepthFormat::D24:
Color::EncodeD24(value, dst_pixel);
break;
case Regs::DepthFormat::D24S8:
// TODO(Subv): Implement the stencil buffer
Color::EncodeD24S8(value, 0, dst_pixel);
Color::EncodeD24X8(value, dst_pixel);
break;
default:
LOG_CRITICAL(HW_GPU, "Unimplemented depth format %u", framebuffer.depth_format);
UNIMPLEMENTED();
@ -158,6 +184,53 @@ static void SetDepth(int x, int y, u32 value) {
}
}
static void SetStencil(int x, int y, u8 value) {
const auto& framebuffer = g_state.regs.framebuffer;
const PAddr addr = framebuffer.GetDepthBufferPhysicalAddress();
u8* depth_buffer = Memory::GetPhysicalPointer(addr);
y = framebuffer.height - y;
const u32 coarse_y = y & ~7;
u32 bytes_per_pixel = Pica::Regs::BytesPerDepthPixel(framebuffer.depth_format);
u32 stride = framebuffer.width * bytes_per_pixel;
u32 dst_offset = VideoCore::GetMortonOffset(x, y, bytes_per_pixel) + coarse_y * stride;
u8* dst_pixel = depth_buffer + dst_offset;
switch (framebuffer.depth_format) {
case Pica::Regs::DepthFormat::D16:
case Pica::Regs::DepthFormat::D24:
// Nothing to do
break;
case Pica::Regs::DepthFormat::D24S8:
Color::EncodeX24S8(value, dst_pixel);
break;
default:
LOG_CRITICAL(HW_GPU, "Unimplemented depth format %u", framebuffer.depth_format);
UNIMPLEMENTED();
break;
}
}
// 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) {
switch (action) {
case Regs::StencilAction::Keep:
return dest;
case Regs::StencilAction::Xor:
return dest ^ ref;
default:
LOG_CRITICAL(HW_GPU, "Unknown stencil action %x", (int)action);
UNIMPLEMENTED();
return 0;
}
}
// NOTE: Assuming that rasterizer coordinates are 12.4 fixed-point values
struct Fix12P4 {
Fix12P4() {}
@ -276,6 +349,9 @@ static void ProcessTriangleInternal(const VertexShader::OutputVertex& v0,
auto textures = regs.GetTextures();
auto tev_stages = regs.GetTevStages();
bool stencil_action_enable = g_state.regs.output_merger.stencil_test.enable && g_state.regs.framebuffer.depth_format == Regs::DepthFormat::D24S8;
const auto stencil_test = g_state.regs.output_merger.stencil_test;
// Enter rasterization loop, starting at the center of the topleft bounding box corner.
// TODO: Not sure if looping through x first might be faster
for (u16 y = min_y + 8; y < max_y; y += 0x10) {
@ -647,6 +723,7 @@ static void ProcessTriangleInternal(const VertexShader::OutputVertex& v0,
}
const auto& output_merger = regs.output_merger;
// TODO: Does alpha testing happen before or after stencil?
if (output_merger.alpha_test.enable) {
bool pass = false;
@ -688,6 +765,54 @@ static void ProcessTriangleInternal(const VertexShader::OutputVertex& v0,
continue;
}
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;
bool pass = false;
switch (stencil_test.func) {
case Regs::CompareFunc::Never:
pass = false;
break;
case Regs::CompareFunc::Always:
pass = true;
break;
case Regs::CompareFunc::Equal:
pass = (ref == dest);
break;
case Regs::CompareFunc::NotEqual:
pass = (ref != dest);
break;
case Regs::CompareFunc::LessThan:
pass = (ref < dest);
break;
case Regs::CompareFunc::LessThanOrEqual:
pass = (ref <= dest);
break;
case Regs::CompareFunc::GreaterThan:
pass = (ref > dest);
break;
case Regs::CompareFunc::GreaterThanOrEqual:
pass = (ref >= dest);
break;
}
if (!pass) {
u8 new_stencil = PerformStencilAction(stencil_test.action_stencil_fail, old_stencil, stencil_test.replacement_value);
SetStencil(x >> 4, y >> 4, new_stencil);
continue;
}
}
// TODO: Does depth indeed only get written even if depth testing is enabled?
if (output_merger.depth_test_enable) {
unsigned num_bits = Regs::DepthBitsPerPixel(regs.framebuffer.depth_format);
@ -732,11 +857,22 @@ static void ProcessTriangleInternal(const VertexShader::OutputVertex& v0,
break;
}
if (!pass)
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);
}
continue;
}
if (output_merger.depth_write_enable)
SetDepth(x >> 4, y >> 4, z);
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);
}
}
auto dest = GetPixel(x >> 4, y >> 4);