mirror of
https://github.com/citra-emu/citra.git
synced 2024-11-16 19:30:04 +00:00
367 lines
17 KiB
C++
367 lines
17 KiB
C++
// Copyright 2014 Citra Emulator Project
|
|
// Licensed under GPLv2
|
|
// Refer to the license.txt file included.
|
|
|
|
#include <algorithm>
|
|
|
|
#include "common/common_types.h"
|
|
|
|
#include "math.h"
|
|
#include "pica.h"
|
|
#include "rasterizer.h"
|
|
#include "vertex_shader.h"
|
|
|
|
#include "debug_utils/debug_utils.h"
|
|
|
|
namespace Pica {
|
|
|
|
namespace Rasterizer {
|
|
|
|
static void DrawPixel(int x, int y, const Math::Vec4<u8>& color) {
|
|
u32* color_buffer = (u32*)Memory::GetPointer(registers.framebuffer.GetColorBufferAddress());
|
|
u32 value = (color.a() << 24) | (color.r() << 16) | (color.g() << 8) | color.b();
|
|
|
|
// Assuming RGBA8 format until actual framebuffer format handling is implemented
|
|
*(color_buffer + x + y * registers.framebuffer.GetWidth() / 2) = value;
|
|
}
|
|
|
|
static u32 GetDepth(int x, int y) {
|
|
u16* depth_buffer = (u16*)Memory::GetPointer(registers.framebuffer.GetDepthBufferAddress());
|
|
|
|
// Assuming 16-bit depth buffer format until actual format handling is implemented
|
|
return *(depth_buffer + x + y * registers.framebuffer.GetWidth() / 2);
|
|
}
|
|
|
|
static void SetDepth(int x, int y, u16 value) {
|
|
u16* depth_buffer = (u16*)Memory::GetPointer(registers.framebuffer.GetDepthBufferAddress());
|
|
|
|
// Assuming 16-bit depth buffer format until actual format handling is implemented
|
|
*(depth_buffer + x + y * registers.framebuffer.GetWidth() / 2) = value;
|
|
}
|
|
|
|
void ProcessTriangle(const VertexShader::OutputVertex& v0,
|
|
const VertexShader::OutputVertex& v1,
|
|
const VertexShader::OutputVertex& v2)
|
|
{
|
|
// NOTE: Assuming that rasterizer coordinates are 12.4 fixed-point values
|
|
struct Fix12P4 {
|
|
Fix12P4() {}
|
|
Fix12P4(u16 val) : val(val) {}
|
|
|
|
static u16 FracMask() { return 0xF; }
|
|
static u16 IntMask() { return (u16)~0xF; }
|
|
|
|
operator u16() const {
|
|
return val;
|
|
}
|
|
|
|
bool operator < (const Fix12P4& oth) const {
|
|
return (u16)*this < (u16)oth;
|
|
}
|
|
|
|
private:
|
|
u16 val;
|
|
};
|
|
|
|
// vertex positions in rasterizer coordinates
|
|
auto FloatToFix = [](float24 flt) {
|
|
return Fix12P4(flt.ToFloat32() * 16.0f);
|
|
};
|
|
auto ScreenToRasterizerCoordinates = [FloatToFix](const Math::Vec3<float24> vec) {
|
|
return Math::Vec3<Fix12P4>{FloatToFix(vec.x), FloatToFix(vec.y), FloatToFix(vec.z)};
|
|
};
|
|
Math::Vec3<Fix12P4> vtxpos[3]{ ScreenToRasterizerCoordinates(v0.screenpos),
|
|
ScreenToRasterizerCoordinates(v1.screenpos),
|
|
ScreenToRasterizerCoordinates(v2.screenpos) };
|
|
|
|
// TODO: Proper scissor rect test!
|
|
u16 min_x = std::min({vtxpos[0].x, vtxpos[1].x, vtxpos[2].x});
|
|
u16 min_y = std::min({vtxpos[0].y, vtxpos[1].y, vtxpos[2].y});
|
|
u16 max_x = std::max({vtxpos[0].x, vtxpos[1].x, vtxpos[2].x});
|
|
u16 max_y = std::max({vtxpos[0].y, vtxpos[1].y, vtxpos[2].y});
|
|
|
|
min_x &= Fix12P4::IntMask();
|
|
min_y &= Fix12P4::IntMask();
|
|
max_x = ((max_x + Fix12P4::FracMask()) & Fix12P4::IntMask());
|
|
max_y = ((max_y + Fix12P4::FracMask()) & Fix12P4::IntMask());
|
|
|
|
// Triangle filling rules: Pixels on the right-sided edge or on flat bottom edges are not
|
|
// drawn. Pixels on any other triangle border are drawn. This is implemented with three bias
|
|
// values which are added to the barycentric coordinates w0, w1 and w2, respectively.
|
|
// NOTE: These are the PSP filling rules. Not sure if the 3DS uses the same ones...
|
|
auto IsRightSideOrFlatBottomEdge = [](const Math::Vec2<Fix12P4>& vtx,
|
|
const Math::Vec2<Fix12P4>& line1,
|
|
const Math::Vec2<Fix12P4>& line2)
|
|
{
|
|
if (line1.y == line2.y) {
|
|
// just check if vertex is above us => bottom line parallel to x-axis
|
|
return vtx.y < line1.y;
|
|
} else {
|
|
// check if vertex is on our left => right side
|
|
// TODO: Not sure how likely this is to overflow
|
|
return (int)vtx.x < (int)line1.x + ((int)line2.x - (int)line1.x) * ((int)vtx.y - (int)line1.y) / ((int)line2.y - (int)line1.y);
|
|
}
|
|
};
|
|
int bias0 = IsRightSideOrFlatBottomEdge(vtxpos[0].xy(), vtxpos[1].xy(), vtxpos[2].xy()) ? -1 : 0;
|
|
int bias1 = IsRightSideOrFlatBottomEdge(vtxpos[1].xy(), vtxpos[2].xy(), vtxpos[0].xy()) ? -1 : 0;
|
|
int bias2 = IsRightSideOrFlatBottomEdge(vtxpos[2].xy(), vtxpos[0].xy(), vtxpos[1].xy()) ? -1 : 0;
|
|
|
|
// TODO: Not sure if looping through x first might be faster
|
|
for (u16 y = min_y; y < max_y; y += 0x10) {
|
|
for (u16 x = min_x; x < max_x; x += 0x10) {
|
|
|
|
// Calculate the barycentric coordinates w0, w1 and w2
|
|
auto orient2d = [](const Math::Vec2<Fix12P4>& vtx1,
|
|
const Math::Vec2<Fix12P4>& vtx2,
|
|
const Math::Vec2<Fix12P4>& vtx3) {
|
|
const auto vec1 = Math::MakeVec(vtx2 - vtx1, 0);
|
|
const auto vec2 = Math::MakeVec(vtx3 - vtx1, 0);
|
|
// TODO: There is a very small chance this will overflow for sizeof(int) == 4
|
|
return Math::Cross(vec1, vec2).z;
|
|
};
|
|
|
|
int w0 = bias0 + orient2d(vtxpos[1].xy(), vtxpos[2].xy(), {x, y});
|
|
int w1 = bias1 + orient2d(vtxpos[2].xy(), vtxpos[0].xy(), {x, y});
|
|
int w2 = bias2 + orient2d(vtxpos[0].xy(), vtxpos[1].xy(), {x, y});
|
|
int wsum = w0 + w1 + w2;
|
|
|
|
// If current pixel is not covered by the current primitive
|
|
if (w0 < 0 || w1 < 0 || w2 < 0)
|
|
continue;
|
|
|
|
// Perspective correct attribute interpolation:
|
|
// Attribute values cannot be calculated by simple linear interpolation since
|
|
// they are not linear in screen space. For example, when interpolating a
|
|
// texture coordinate across two vertices, something simple like
|
|
// u = (u0*w0 + u1*w1)/(w0+w1)
|
|
// will not work. However, the attribute value divided by the
|
|
// clipspace w-coordinate (u/w) and and the inverse w-coordinate (1/w) are linear
|
|
// in screenspace. Hence, we can linearly interpolate these two independently and
|
|
// calculate the interpolated attribute by dividing the results.
|
|
// I.e.
|
|
// u_over_w = ((u0/v0.pos.w)*w0 + (u1/v1.pos.w)*w1)/(w0+w1)
|
|
// one_over_w = (( 1/v0.pos.w)*w0 + ( 1/v1.pos.w)*w1)/(w0+w1)
|
|
// u = u_over_w / one_over_w
|
|
//
|
|
// The generalization to three vertices is straightforward in baricentric coordinates.
|
|
auto GetInterpolatedAttribute = [&](float24 attr0, float24 attr1, float24 attr2) {
|
|
auto attr_over_w = Math::MakeVec(attr0 / v0.pos.w,
|
|
attr1 / v1.pos.w,
|
|
attr2 / v2.pos.w);
|
|
auto w_inverse = Math::MakeVec(float24::FromFloat32(1.f) / v0.pos.w,
|
|
float24::FromFloat32(1.f) / v1.pos.w,
|
|
float24::FromFloat32(1.f) / v2.pos.w);
|
|
auto baricentric_coordinates = Math::MakeVec(float24::FromFloat32(w0),
|
|
float24::FromFloat32(w1),
|
|
float24::FromFloat32(w2));
|
|
|
|
float24 interpolated_attr_over_w = Math::Dot(attr_over_w, baricentric_coordinates);
|
|
float24 interpolated_w_inverse = Math::Dot(w_inverse, baricentric_coordinates);
|
|
return interpolated_attr_over_w / interpolated_w_inverse;
|
|
};
|
|
|
|
Math::Vec4<u8> primary_color{
|
|
(u8)(GetInterpolatedAttribute(v0.color.r(), v1.color.r(), v2.color.r()).ToFloat32() * 255),
|
|
(u8)(GetInterpolatedAttribute(v0.color.g(), v1.color.g(), v2.color.g()).ToFloat32() * 255),
|
|
(u8)(GetInterpolatedAttribute(v0.color.b(), v1.color.b(), v2.color.b()).ToFloat32() * 255),
|
|
(u8)(GetInterpolatedAttribute(v0.color.a(), v1.color.a(), v2.color.a()).ToFloat32() * 255)
|
|
};
|
|
|
|
Math::Vec4<u8> texture_color{};
|
|
float24 u = GetInterpolatedAttribute(v0.tc0.u(), v1.tc0.u(), v2.tc0.u());
|
|
float24 v = GetInterpolatedAttribute(v0.tc0.v(), v1.tc0.v(), v2.tc0.v());
|
|
if (registers.texturing_enable) {
|
|
// Images are split into 8x8 tiles. Each tile is composed of four 4x4 subtiles each
|
|
// of which is composed of four 2x2 subtiles each of which is composed of four texels.
|
|
// Each structure is embedded into the next-bigger one in a diagonal pattern, e.g.
|
|
// texels are laid out in a 2x2 subtile like this:
|
|
// 2 3
|
|
// 0 1
|
|
//
|
|
// The full 8x8 tile has the texels arranged like this:
|
|
//
|
|
// 42 43 46 47 58 59 62 63
|
|
// 40 41 44 45 56 57 60 61
|
|
// 34 35 38 39 50 51 54 55
|
|
// 32 33 36 37 48 49 52 53
|
|
// 10 11 14 15 26 27 30 31
|
|
// 08 09 12 13 24 25 28 29
|
|
// 02 03 06 07 18 19 22 23
|
|
// 00 01 04 05 16 17 20 21
|
|
|
|
// TODO: This is currently hardcoded for RGB8
|
|
u32* texture_data = (u32*)Memory::GetPointer(registers.texture0.GetPhysicalAddress());
|
|
|
|
// TODO(neobrain): Not sure if this swizzling pattern is used for all textures.
|
|
// To be flexible in case different but similar patterns are used, we keep this
|
|
// somewhat inefficient code around for now.
|
|
int s = (int)(u * float24::FromFloat32(registers.texture0.width)).ToFloat32();
|
|
int t = (int)(v * float24::FromFloat32(registers.texture0.height)).ToFloat32();
|
|
int texel_index_within_tile = 0;
|
|
for (int block_size_index = 0; block_size_index < 3; ++block_size_index) {
|
|
int sub_tile_width = 1 << block_size_index;
|
|
int sub_tile_height = 1 << block_size_index;
|
|
|
|
int sub_tile_index = (s & sub_tile_width) << block_size_index;
|
|
sub_tile_index += 2 * ((t & sub_tile_height) << block_size_index);
|
|
texel_index_within_tile += sub_tile_index;
|
|
}
|
|
|
|
const int block_width = 8;
|
|
const int block_height = 8;
|
|
|
|
int coarse_s = (s / block_width) * block_width;
|
|
int coarse_t = (t / block_height) * block_height;
|
|
|
|
const int row_stride = registers.texture0.width * 3;
|
|
u8* source_ptr = (u8*)texture_data + coarse_s * block_height * 3 + coarse_t * row_stride + texel_index_within_tile * 3;
|
|
texture_color.r() = source_ptr[2];
|
|
texture_color.g() = source_ptr[1];
|
|
texture_color.b() = source_ptr[0];
|
|
texture_color.a() = 0xFF;
|
|
|
|
DebugUtils::DumpTexture(registers.texture0, (u8*)texture_data);
|
|
}
|
|
|
|
// Texture environment - consists of 6 stages of color and alpha combining.
|
|
//
|
|
// Color combiners take three input color values from some source (e.g. interpolated
|
|
// vertex color, texture color, previous stage, etc), perform some very simple
|
|
// operations on each of them (e.g. inversion) and then calculate the output color
|
|
// with some basic arithmetic. Alpha combiners can be configured separately but work
|
|
// analogously.
|
|
Math::Vec4<u8> combiner_output;
|
|
for (auto tev_stage : registers.GetTevStages()) {
|
|
using Source = Regs::TevStageConfig::Source;
|
|
using ColorModifier = Regs::TevStageConfig::ColorModifier;
|
|
using AlphaModifier = Regs::TevStageConfig::AlphaModifier;
|
|
using Operation = Regs::TevStageConfig::Operation;
|
|
|
|
auto GetColorSource = [&](Source source) -> Math::Vec3<u8> {
|
|
switch (source) {
|
|
case Source::PrimaryColor:
|
|
return primary_color.rgb();
|
|
|
|
case Source::Texture0:
|
|
return texture_color.rgb();
|
|
|
|
case Source::Constant:
|
|
return {tev_stage.const_r, tev_stage.const_g, tev_stage.const_b};
|
|
|
|
case Source::Previous:
|
|
return combiner_output.rgb();
|
|
|
|
default:
|
|
ERROR_LOG(GPU, "Unknown color combiner source %d\n", (int)source);
|
|
return {};
|
|
}
|
|
};
|
|
|
|
auto GetAlphaSource = [&](Source source) -> u8 {
|
|
switch (source) {
|
|
case Source::PrimaryColor:
|
|
return primary_color.a();
|
|
|
|
case Source::Texture0:
|
|
return texture_color.a();
|
|
|
|
case Source::Constant:
|
|
return tev_stage.const_a;
|
|
|
|
case Source::Previous:
|
|
return combiner_output.a();
|
|
|
|
default:
|
|
ERROR_LOG(GPU, "Unknown alpha combiner source %d\n", (int)source);
|
|
return 0;
|
|
}
|
|
};
|
|
|
|
auto GetColorModifier = [](ColorModifier factor, const Math::Vec3<u8>& values) -> Math::Vec3<u8> {
|
|
switch (factor)
|
|
{
|
|
case ColorModifier::SourceColor:
|
|
return values;
|
|
default:
|
|
ERROR_LOG(GPU, "Unknown color factor %d\n", (int)factor);
|
|
return {};
|
|
}
|
|
};
|
|
|
|
auto GetAlphaModifier = [](AlphaModifier factor, u8 value) -> u8 {
|
|
switch (factor) {
|
|
case AlphaModifier::SourceAlpha:
|
|
return value;
|
|
default:
|
|
ERROR_LOG(GPU, "Unknown color factor %d\n", (int)factor);
|
|
return 0;
|
|
}
|
|
};
|
|
|
|
auto ColorCombine = [](Operation op, const Math::Vec3<u8> input[3]) -> Math::Vec3<u8> {
|
|
switch (op) {
|
|
case Operation::Replace:
|
|
return input[0];
|
|
|
|
case Operation::Modulate:
|
|
return ((input[0] * input[1]) / 255).Cast<u8>();
|
|
|
|
default:
|
|
ERROR_LOG(GPU, "Unknown color combiner operation %d\n", (int)op);
|
|
return {};
|
|
}
|
|
};
|
|
|
|
auto AlphaCombine = [](Operation op, const std::array<u8,3>& input) -> u8 {
|
|
switch (op) {
|
|
case Operation::Replace:
|
|
return input[0];
|
|
|
|
case Operation::Modulate:
|
|
return input[0] * input[1] / 255;
|
|
|
|
default:
|
|
ERROR_LOG(GPU, "Unknown alpha combiner operation %d\n", (int)op);
|
|
return 0;
|
|
}
|
|
};
|
|
|
|
// color combiner
|
|
// NOTE: Not sure if the alpha combiner might use the color output of the previous
|
|
// stage as input. Hence, we currently don't directly write the result to
|
|
// combiner_output.rgb(), but instead store it in a temporary variable until
|
|
// alpha combining has been done.
|
|
Math::Vec3<u8> color_result[3] = {
|
|
GetColorModifier(tev_stage.color_modifier1, GetColorSource(tev_stage.color_source1)),
|
|
GetColorModifier(tev_stage.color_modifier2, GetColorSource(tev_stage.color_source2)),
|
|
GetColorModifier(tev_stage.color_modifier3, GetColorSource(tev_stage.color_source3))
|
|
};
|
|
auto color_output = ColorCombine(tev_stage.color_op, color_result);
|
|
|
|
// alpha combiner
|
|
std::array<u8,3> alpha_result = {
|
|
GetAlphaModifier(tev_stage.alpha_modifier1, GetAlphaSource(tev_stage.alpha_source1)),
|
|
GetAlphaModifier(tev_stage.alpha_modifier2, GetAlphaSource(tev_stage.alpha_source2)),
|
|
GetAlphaModifier(tev_stage.alpha_modifier3, GetAlphaSource(tev_stage.alpha_source3))
|
|
};
|
|
auto alpha_output = AlphaCombine(tev_stage.alpha_op, alpha_result);
|
|
|
|
combiner_output = Math::MakeVec(color_output, alpha_output);
|
|
}
|
|
|
|
// TODO: Not sure if the multiplication by 65535 has already been taken care
|
|
// of when transforming to screen coordinates or not.
|
|
u16 z = (u16)(((float)v0.screenpos[2].ToFloat32() * w0 +
|
|
(float)v1.screenpos[2].ToFloat32() * w1 +
|
|
(float)v2.screenpos[2].ToFloat32() * w2) * 65535.f / wsum);
|
|
SetDepth(x >> 4, y >> 4, z);
|
|
|
|
DrawPixel(x >> 4, y >> 4, combiner_output);
|
|
}
|
|
}
|
|
}
|
|
|
|
} // namespace Rasterizer
|
|
|
|
} // namespace Pica
|