swrasterizer: implement shadow map rendering

This commit is contained in:
wwylele 2018-03-12 19:45:30 +02:00
parent ae75d3032f
commit 9f8ff7b04e
4 changed files with 77 additions and 1 deletions

View File

@ -15,6 +15,12 @@
namespace Pica {
struct FramebufferRegs {
enum class FragmentOperationMode : u32 {
Default = 0,
Gas = 1,
Shadow = 3,
};
enum class LogicOp : u32 {
Clear = 0,
And = 1,
@ -84,6 +90,7 @@ struct FramebufferRegs {
struct {
union {
BitField<0, 2, FragmentOperationMode> fragment_operation_mode;
// If false, logic blending is used
BitField<8, 1, u32> alphablend_enable;
};
@ -274,7 +281,14 @@ struct FramebufferRegs {
ASSERT_MSG(false, "Unknown depth format %u", static_cast<u32>(format));
}
INSERT_PADDING_WORDS(0x20);
INSERT_PADDING_WORDS(0x10); // Gas related registers
union {
BitField<0, 16, u32> constant; // float1.5.10
BitField<16, 16, u32> linear; // float1.5.10
} shadow;
INSERT_PADDING_WORDS(0xF);
};
static_assert(sizeof(FramebufferRegs) == 0x40 * sizeof(u32),

View File

@ -359,5 +359,54 @@ u8 LogicOp(u8 src, u8 dest, FramebufferRegs::LogicOp op) {
UNREACHABLE();
};
// Decode/Encode for shadow map format. It is similar to D24S8 format, but the depth field is in
// big-endian
static const Math::Vec2<u32> DecodeD24S8Shadow(const u8* bytes) {
return {static_cast<u32>((bytes[0] << 16) | (bytes[1] << 8) | bytes[2]), bytes[3]};
}
static void EncodeD24X8Shadow(u32 depth, u8* bytes) {
bytes[2] = depth & 0xFF;
bytes[1] = (depth >> 8) & 0xFF;
bytes[0] = (depth >> 16) & 0xFF;
}
static void EncodeX24S8Shadow(u8 stencil, u8* bytes) {
bytes[3] = stencil;
}
void DrawShadowMapPixel(int x, int y, u32 depth, u8 stencil) {
const auto& framebuffer = g_state.regs.framebuffer.framebuffer;
const auto& shadow = g_state.regs.framebuffer.shadow;
const PAddr addr = framebuffer.GetColorBufferPhysicalAddress();
y = framebuffer.height - y;
const u32 coarse_y = y & ~7;
u32 bytes_per_pixel = 4;
u32 dst_offset = VideoCore::GetMortonOffset(x, y, bytes_per_pixel) +
coarse_y * framebuffer.width * bytes_per_pixel;
u8* dst_pixel = Memory::GetPhysicalPointer(addr) + dst_offset;
auto ref = DecodeD24S8Shadow(dst_pixel);
u32 ref_z = ref.x;
u32 ref_s = ref.y;
if (depth < ref_z) {
if (stencil == 0) {
EncodeD24X8Shadow(depth, dst_pixel);
} else {
float16 constant = float16::FromRaw(shadow.constant);
float16 linear = float16::FromRaw(shadow.linear);
float16 x = float16::FromFloat32(static_cast<float>(depth) / ref_z);
float16 stencil_new = float16::FromFloat32(stencil) / (constant + linear * x);
stencil = static_cast<u8>(MathUtil::Clamp(stencil_new.ToFloat32(), 0.0f, 255.0f));
if (stencil < ref_s)
EncodeX24S8Shadow(stencil, dst_pixel);
}
}
}
} // namespace Rasterizer
} // namespace Pica

View File

@ -25,5 +25,7 @@ Math::Vec4<u8> EvaluateBlendEquation(const Math::Vec4<u8>& src, const Math::Vec4
u8 LogicOp(u8 src, u8 dest, FramebufferRegs::LogicOp op);
void DrawShadowMapPixel(int x, int y, u32 depth, u8 stencil);
} // namespace Rasterizer
} // namespace Pica

View File

@ -572,6 +572,17 @@ static void ProcessTriangleInternal(const Vertex& v0, const Vertex& v1, const Ve
}
const auto& output_merger = regs.framebuffer.output_merger;
if (output_merger.fragment_operation_mode ==
FramebufferRegs::FragmentOperationMode::Shadow) {
u32 depth_int = static_cast<u32>(depth * 0xFFFFFF);
// use green color as the shadow intensity
u8 stencil = combiner_output.y;
DrawShadowMapPixel(x >> 4, y >> 4, depth_int, stencil);
// skip the normal output merger pipeline if it is in shadow mode
continue;
}
// TODO: Does alpha testing happen before or after stencil?
if (output_merger.alpha_test.enable) {
bool pass = false;