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SoftGPU: Rasterize triangles in chunks of 4 pixels.
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Not very optimal yet.
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@unknownbrackets
unknownbrackets committed Apr 23, 2017
1 parent ee3fe70 commit 3627c7f
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Showing 2 changed files with 120 additions and 58 deletions.
4 changes: 4 additions & 0 deletions GPU/Math3D.h
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Original file line number Diff line number Diff line change
Expand Up @@ -599,6 +599,10 @@ class Vec4
{
return Vec4(x*other.x, y*other.y, z*other.z, w*other.w);
}
Vec4 operator | (const Vec4 &other) const
{
return Vec4(x | other.x, y | other.y, z | other.z, w | other.w);
}
template<typename V>
Vec4 operator * (const V& f) const
{
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174 changes: 116 additions & 58 deletions GPU/Software/Rasterizer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1180,19 +1180,47 @@ static inline Vec2<float> Interpolate(const Vec2<float> &c0, const Vec2<float> &
#endif
}

struct TriangleEdge {
Vec4<int> Start(const ScreenCoords &v0, const ScreenCoords &v1, const ScreenCoords &origin);
inline Vec4<int> StepX(const Vec4<int> &w);
inline Vec4<int> StepY(const Vec4<int> &w);

Vec4<int> stepX;
Vec4<int> stepY;
};

Vec4<int> TriangleEdge::Start(const ScreenCoords &v0, const ScreenCoords &v1, const ScreenCoords &origin) {
Vec4<int> initX = Vec4<int>::AssignToAll(origin.x) + Vec4<int>(0, 16, 0, 16);
Vec4<int> initY = Vec4<int>::AssignToAll(origin.y) + Vec4<int>(0, 0, 16, 16);

// orient2d refactored.
int xf = v0.y - v1.y;
int yf = v1.x - v0.x;
int c = v1.y * v0.x - v1.x * v0.y;

stepX = Vec4<int>::AssignToAll(xf * 16 * 2);
stepY = Vec4<int>::AssignToAll(yf * 16 * 2);

return Vec4<int>::AssignToAll(xf) * initX + Vec4<int>::AssignToAll(yf) * initY + Vec4<int>::AssignToAll(c);
}

inline Vec4<int> TriangleEdge::StepX(const Vec4<int> &w) {
return w + stepX;
}

inline Vec4<int> TriangleEdge::StepY(const Vec4<int> &w) {
return w + stepY;
}

template <bool clearMode>
void DrawTriangleSlice(
const VertexData& v0, const VertexData& v1, const VertexData& v2,
int minX, int minY, int maxX, int maxY,
int y1, int y2)
int hy1, int hy2)
{
Vec2<int> d01((int)v0.screenpos.x - (int)v1.screenpos.x, (int)v0.screenpos.y - (int)v1.screenpos.y);
Vec2<int> d02((int)v0.screenpos.x - (int)v2.screenpos.x, (int)v0.screenpos.y - (int)v2.screenpos.y);
Vec2<int> d12((int)v1.screenpos.x - (int)v2.screenpos.x, (int)v1.screenpos.y - (int)v2.screenpos.y);

int bias0 = IsRightSideOrFlatBottomLine(v0.screenpos.xy(), v1.screenpos.xy(), v2.screenpos.xy()) ? -1 : 0;
int bias1 = IsRightSideOrFlatBottomLine(v1.screenpos.xy(), v2.screenpos.xy(), v0.screenpos.xy()) ? -1 : 0;
int bias2 = IsRightSideOrFlatBottomLine(v2.screenpos.xy(), v0.screenpos.xy(), v1.screenpos.xy()) ? -1 : 0;
Vec4<int> bias0 = Vec4<int>::AssignToAll(IsRightSideOrFlatBottomLine(v0.screenpos.xy(), v1.screenpos.xy(), v2.screenpos.xy()) ? -1 : 0);
Vec4<int> bias1 = Vec4<int>::AssignToAll(IsRightSideOrFlatBottomLine(v1.screenpos.xy(), v2.screenpos.xy(), v0.screenpos.xy()) ? -1 : 0);
Vec4<int> bias2 = Vec4<int>::AssignToAll(IsRightSideOrFlatBottomLine(v2.screenpos.xy(), v0.screenpos.xy(), v1.screenpos.xy()) ? -1 : 0);

int texbufwidthbytes[8] = {0};

Expand Down Expand Up @@ -1225,89 +1253,118 @@ void DrawTriangleSlice(
}
}

TriangleEdge e0;
TriangleEdge e1;
TriangleEdge e2;

ScreenCoords pprime(minX, minY, 0);
int w0_base = orient2d(v1.screenpos, v2.screenpos, pprime);
int w1_base = orient2d(v2.screenpos, v0.screenpos, pprime);
int w2_base = orient2d(v0.screenpos, v1.screenpos, pprime);
Vec4<int> w0_base = e0.Start(v1.screenpos, v2.screenpos, pprime);
Vec4<int> w1_base = e1.Start(v2.screenpos, v0.screenpos, pprime);
Vec4<int> w2_base = e2.Start(v0.screenpos, v1.screenpos, pprime);

// Step forward to y1 (slice..)
w0_base += orient2dIncY(d12.x) * 16 * y1;
w1_base += orient2dIncY(-d02.x) * 16 * y1;
w2_base += orient2dIncY(d01.x) * 16 * y1;
w0_base += e0.stepY * hy1;
w1_base += e1.stepY * hy1;
w2_base += e2.stepY * hy1;

// All the z values are the same, no interpolation required.
// This is common, and when we interpolate, we lose accuracy.
const bool flatZ = v0.screenpos.z == v1.screenpos.z && v0.screenpos.z == v2.screenpos.z;

for (pprime.y = minY + y1 * 16; pprime.y < minY + y2 * 16; pprime.y += 16,
w0_base += orient2dIncY(d12.x)*16,
w1_base += orient2dIncY(-d02.x)*16,
w2_base += orient2dIncY(d01.x)*16) {
int w0 = w0_base;
int w1 = w1_base;
int w2 = w2_base;
for (pprime.y = minY + hy1 * 32; pprime.y < minY + hy2 * 32; pprime.y += 32,
w0_base = e0.StepY(w0_base),
w1_base = e1.StepY(w1_base),
w2_base = e2.StepY(w2_base)) {
Vec4<int> w0 = w0_base;
Vec4<int> w1 = w1_base;
Vec4<int> w2 = w2_base;

pprime.x = minX;
DrawingCoords p = TransformUnit::ScreenToDrawing(pprime);

for (; pprime.x <= maxX; pprime.x +=16,
w0 += orient2dIncX(d12.y)*16,
w1 += orient2dIncX(-d02.y)*16,
w2 += orient2dIncX(d01.y)*16,
p.x = (p.x + 1) & 0x3FF) {
for (; pprime.x <= maxX; pprime.x += 32,
w0 = e0.StepX(w0),
w1 = e1.StepX(w1),
w2 = e2.StepX(w2),
p.x = (p.x + 2) & 0x3FF) {

// If p is on or inside all edges, render pixel
if (w0 + bias0 >= 0 && w1 + bias1 >= 0 && w2 + bias2 >= 0) {
int wsum = w0 + w1 + w2;
if (wsum == 0.0f)
continue;
float wsum_recip = 1.0f / (float)wsum;

Vec4<int> prim_color;
Vec3<int> sec_color;
Vec4<int> mask = (w0 + bias0) | (w1 + bias1) | (w2 + bias2);
if (mask.x >= 0 || mask.y >= 0 || mask.z >= 0 || mask.w >= 0) {
Vec4<float> wsum = (w0 + w1 + w2).Cast<float>();
Vec4<float> wsum_recip(1.0f / wsum.x, 1.0f / wsum.y, 1.0f / wsum.z, 1.0f / wsum.w);

Vec4<int> prim_color[4];
Vec3<int> sec_color[4];
if (gstate.getShadeMode() == GE_SHADE_GOURAUD && !clearMode) {
// Does the PSP do perspective-correct color interpolation? The GC doesn't.
prim_color = Interpolate(v0.color0, v1.color0, v2.color0, w0, w1, w2, wsum_recip);
sec_color = Interpolate(v0.color1, v1.color1, v2.color1, w0, w1, w2, wsum_recip);
for (int i = 0; i < 4; ++i) {
prim_color[i] = Interpolate(v0.color0, v1.color0, v2.color0, w0[i], w1[i], w2[i], wsum_recip[i]);
sec_color[i] = Interpolate(v0.color1, v1.color1, v2.color1, w0[i], w1[i], w2[i], wsum_recip[i]);
}
} else {
prim_color = v2.color0;
sec_color = v2.color1;
for (int i = 0; i < 4; ++i) {
prim_color[i] = v2.color0;
sec_color[i] = v2.color1;
}
}

if (gstate.isTextureMapEnabled() && !clearMode) {
if (gstate.isModeThrough()) {
Vec2<float> texcoords = Interpolate(v0.texturecoords, v1.texturecoords, v2.texturecoords, w0, w1, w2, wsum_recip);
ApplyTexturing(prim_color, texcoords.s(), texcoords.t(), maxTexLevel, magFilt, texptr, texbufwidthbytes);
for (int i = 0; i < 4; ++i) {
Vec2<float> texcoords = Interpolate(v0.texturecoords, v1.texturecoords, v2.texturecoords, w0[i], w1[i], w2[i], wsum_recip[i]);
ApplyTexturing(prim_color[i], texcoords.s(), texcoords.t(), maxTexLevel, magFilt, texptr, texbufwidthbytes);
}
} else {
// Texture coordinate interpolation must definitely be perspective-correct.
float s = 0, t = 0;
GetTextureCoordinates(v0, v1, v2, w0, w1, w2, s, t);
ApplyTexturing(prim_color, s, t, maxTexLevel, magFilt, texptr, texbufwidthbytes);
for (int i = 0; i < 4; ++i) {
float s = 0, t = 0;
GetTextureCoordinates(v0, v1, v2, w0[i], w1[i], w2[i], s, t);
ApplyTexturing(prim_color[i], s, t, maxTexLevel, magFilt, texptr, texbufwidthbytes);
}
}
}

if (!clearMode) {
// TODO: Tried making Vec4 do this, but things got slower.
for (int i = 0; i < 4; ++i) {
#if defined(_M_SSE)
const __m128i sec = _mm_and_si128(sec_color.ivec, _mm_set_epi32(0, -1, -1, -1));
prim_color.ivec = _mm_add_epi32(prim_color.ivec, sec);
// TODO: Tried making Vec4 do this, but things got slower.
const __m128i sec = _mm_and_si128(sec_color[i].ivec, _mm_set_epi32(0, -1, -1, -1));
prim_color[i].ivec = _mm_add_epi32(prim_color[i].ivec, sec);
#else
prim_color += Vec4<int>(sec_color, 0);
prim_color[i] += Vec4<int>(sec_color[i], 0);
#endif
}
}

int fog = 255;
Vec4<int> fog = Vec4<int>::AssignToAll(255);
if (gstate.isFogEnabled() && !clearMode) {
fog = ClampFogDepth(((float)v0.fogdepth * w0 + (float)v1.fogdepth * w1 + (float)v2.fogdepth * w2) * wsum_recip);
Vec4<float> fogdepths = w0.Cast<float>() * v0.fogdepth + w1.Cast<float>() * v1.fogdepth + w2.Cast<float>() * v2.fogdepth;
fogdepths = fogdepths * wsum_recip;
for (int i = 0; i < 4; ++i) {
fog[i] = ClampFogDepth(fogdepths[i]);
}
}

Vec4<int> z;
if (flatZ) {
z = Vec4<int>::AssignToAll(v2.screenpos.z);
} else {
// TODO: Is that the correct way to interpolate?
Vec4<float> zfloats = w0.Cast<float>() * v0.screenpos.z + w1.Cast<float>() * v1.screenpos.z + w2.Cast<float>() * v2.screenpos.z;
z = (zfloats * wsum_recip).Cast<int>();
}

u16 z = v2.screenpos.z;
// TODO: Is that the correct way to interpolate?
// Without the (u32), this causes an ICE in some versions of gcc.
if (!flatZ)
z = (u16)(u32)(((float)v0.screenpos.z * w0 + (float)v1.screenpos.z * w1 + (float)v2.screenpos.z * w2) * wsum_recip);
DrawingCoords subp = p;
for (int i = 0; i < 4; ++i) {
if (mask[i] < 0) {
continue;
}
subp.x = p.x + (i & 1);
subp.y = p.y + (i / 2);

DrawSinglePixel<clearMode>(p, z, fog, prim_color);
DrawSinglePixel<clearMode>(subp, (u16)z[i], fog[i], prim_color[i]);
}
}
}
}
Expand Down Expand Up @@ -1338,9 +1395,10 @@ void DrawTriangle(const VertexData& v0, const VertexData& v1, const VertexData&
minY = std::max(minY, (int)TransformUnit::DrawingToScreen(scissorTL).y);
maxY = std::min(maxY, (int)TransformUnit::DrawingToScreen(scissorBR).y);

int range = (maxY - minY) / 16 + 1;
// 32 because we do two pixels at once, and we don't want overlap.
int range = (maxY - minY) / 32 + 1;
if (gstate.isModeClear()) {
if (range >= 24 && (maxX - minX) >= 24 * 16) {
if (range >= 12 && (maxX - minX) >= 24 * 16) {
auto bound = [&](int a, int b) -> void {
DrawTriangleSlice<true>(v0, v1, v2, minX, minY, maxX, maxY, a, b);
};
Expand All @@ -1349,7 +1407,7 @@ void DrawTriangle(const VertexData& v0, const VertexData& v1, const VertexData&
DrawTriangleSlice<true>(v0, v1, v2, minX, minY, maxX, maxY, 0, range);
}
} else {
if (range >= 24 && (maxX - minX) >= 24 * 16) {
if (range >= 12 && (maxX - minX) >= 24 * 16) {
auto bound = [&](int a, int b) -> void {
DrawTriangleSlice<false>(v0, v1, v2, minX, minY, maxX, maxY, a, b);
};
Expand Down

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