src/Shader/SetupRoutine.cpp

// SwiftShader Software Renderer
//
// Copyright(c) 2005-2011 TransGaming Inc.
//
// All rights reserved. No part of this software may be copied, distributed, transmitted,
// transcribed, stored in a retrieval system, translated into any human or computer
// language by any means, or disclosed to third parties without the explicit written
// agreement of TransGaming Inc. Without such an agreement, no rights or licenses, express
// or implied, including but not limited to any patent rights, are granted to you.
//

#include "SetupRoutine.hpp"

#include "Constants.hpp"
#include "Renderer/Primitive.hpp"
#include "Renderer/Polygon.hpp"
#include "Renderer/Renderer.hpp"
#include "Reactor/Shell.hpp"

namespace sw
{
	extern bool complementaryDepthBuffer;
	extern TranscendentalPrecision logPrecision;

	SetupRoutine::SetupRoutine(const SetupProcessor::State &state) : state(state)
	{
		routine = 0;
	}

	SetupRoutine::~SetupRoutine()
	{
	}

	void SetupRoutine::generate()
	{
		Function<Bool, Pointer<Byte>, Pointer<Byte>, Pointer<Byte>, Pointer<Byte>> function;
		{
			Pointer<Byte> primitive(function.arg(0));
			Pointer<Byte> tri(function.arg(1));
			Pointer<Byte> polygon(function.arg(2));
			Pointer<Byte> data(function.arg(3));

			Pointer<Byte> constants = *Pointer<Pointer<Byte>>(data + OFFSET(DrawData,constants));

			const bool point = state.isDrawPoint;
			const bool sprite = state.pointSprite;
			const bool line = state.isDrawLine;
			const bool triangle = state.isDrawSolidTriangle || sprite;
			const bool solidTriangle = state.isDrawSolidTriangle;

			const int V0 = OFFSET(Triangle,v0);
			const int V1 = (triangle || line) ? OFFSET(Triangle,v1) : OFFSET(Triangle,v0);
			const int V2 = triangle ? OFFSET(Triangle,v2) : (line ? OFFSET(Triangle,v1) : OFFSET(Triangle,v0));

			int pos = state.positionRegister;

			Pointer<Byte> v0 = tri + V0;
			Pointer<Byte> v1 = tri + V1;
			Pointer<Byte> v2 = tri + V2;

			Array<Int> X(16);
			Array<Int> Y(16);

			X[0] = *Pointer<Int>(v0 + OFFSET(Vertex,X));
			X[1] = *Pointer<Int>(v1 + OFFSET(Vertex,X));
			X[2] = *Pointer<Int>(v2 + OFFSET(Vertex,X));

			Y[0] = *Pointer<Int>(v0 + OFFSET(Vertex,Y));
			Y[1] = *Pointer<Int>(v1 + OFFSET(Vertex,Y));
			Y[2] = *Pointer<Int>(v2 + OFFSET(Vertex,Y));

			Int d = 1;     // Winding direction

			// Culling
			if(solidTriangle)
			{
				Float x0 = Float(X[0]);
				Float x1 = Float(X[1]);
				Float x2 = Float(X[2]);

				Float y0 = Float(Y[0]);
				Float y1 = Float(Y[1]);
				Float y2 = Float(Y[2]);

				Float A = (y2 - y0) * x1 + (y1 - y2) * x0 + (y0 - y1) * x2;   // Area

				If(A == Float(0.0f))
				{
					Return(false);
				}

				Float w0w1w2 = *Pointer<Float>(v0 + pos * 16 + 12) *
							   *Pointer<Float>(v1 + pos * 16 + 12) *
							   *Pointer<Float>(v2 + pos * 16 + 12);

				A = IfThenElse(w0w1w2 < Float(0.0f), -A, A);

				if(state.cullMode == Context::CULL_CLOCKWISE)
				{
					If(A >= Float(0.0f)) Return(false);
				}
				else if(state.cullMode == Context::CULL_COUNTERCLOCKWISE)
				{
					If(A <= Float(0.0f)) Return(false);
				}

				d = IfThenElse(A < Float(0.0f), d, Int(0));

				if(state.twoSidedStencil)
				{
					Byte8 clockwiseMask = IfThenElse(A > Float(0.0f), Byte8(0xFFFFFFFFFFFFFFFF), Byte8(0x0000000000000000));

					*Pointer<Byte8>(primitive + OFFSET(Primitive,clockwiseMask)) =  clockwiseMask;
					*Pointer<Byte8>(primitive + OFFSET(Primitive,invClockwiseMask)) = ~clockwiseMask;
				}

				if(state.vFace)
				{
					*Pointer<Float>(primitive + OFFSET(Primitive,area)) = Float(0.5f) * A;
				}
			}
			else
			{
				if(state.twoSidedStencil)
				{
					*Pointer<Byte8>(primitive + OFFSET(Primitive,clockwiseMask)) =  Byte8(0xFFFFFFFFFFFFFFFF);
					*Pointer<Byte8>(primitive + OFFSET(Primitive,invClockwiseMask)) = Byte8(0x0000000000000000);
				}
			}

			Int n = *Pointer<Int>(polygon + OFFSET(Polygon,n));
			Int m = *Pointer<Int>(polygon + OFFSET(Polygon,i));

			If(m != 0 || Bool(!solidTriangle))   // Clipped triangle; reproject
			{
				Pointer<Byte> V = polygon + OFFSET(Polygon,P) + m * sizeof(void*) * 16;
		
				Int i = 0;

				Do
				{
					Pointer<Float4> p = *Pointer<Pointer<Float4>>(V + i * sizeof(void*));
					Float4 v = *Pointer<Float4>(p, 16);

					Float w = v.w;
					Float rhw = IfThenElse(w != Float(0.0f), Float(1.0f) / w, Float(1.0f));

					X[i] = RoundInt(*Pointer<Float>(data + OFFSET(DrawData,LLLLx16)) + v.x * rhw * *Pointer<Float>(data + OFFSET(DrawData,WWWWx16)));
					Y[i] = RoundInt(*Pointer<Float>(data + OFFSET(DrawData,TTTTx16)) + v.y * rhw * *Pointer<Float>(data + OFFSET(DrawData,HHHHx16)));

					i++;
				}
				Until(i >= n)
			}

			// Vertical range
			Int yMin = Y[0];
			Int yMax = Y[0];
			
			Int i = 1;
			
			Do
			{
				yMin = IfThenElse(Y[i] < yMin, Int(Y[i]), yMin);   // FIXME: Min(Y[i], yMin)
				yMax = IfThenElse(Y[i] > yMax, Int(Y[i]), yMax);   // FIXME: Max(Y[i], yMax)

				i++;
			}
			Until(i >= n)

			if(state.multiSample > 1)
			{
				yMin = (yMin + 0x0A) >> 4;
				yMax = (yMax + 0x14) >> 4;
			}
			else
			{
				yMin = (yMin + 0x0F) >> 4;
				yMax = (yMax + 0x0F) >> 4;
			}

			If(yMin == yMax)
			{
				Return(false);
			}
		
			For(Int q = 0, q < state.multiSample, q++)
			{
				Array<Int> Xq(16);
				Array<Int> Yq(16);

				Int i = 0;

				Do
				{
					Xq[i] = X[i];
					Yq[i] = Y[i];

					if(state.multiSample > 1)
					{
						Xq[i] = Xq[i] + *Pointer<Int>(constants + OFFSET(Constants,Xf) + q * sizeof(int));
						Yq[i] = Yq[i] + *Pointer<Int>(constants + OFFSET(Constants,Yf) + q * sizeof(int));
					}

					i++;
				}
				Until(i >= n)

				Pointer<Byte> leftEdge = Pointer<Byte>(primitive + OFFSET(Primitive,outline->left)) + q * sizeof(Primitive);
				Pointer<Byte> rightEdge = Pointer<Byte>(primitive + OFFSET(Primitive,outline->right)) + q * sizeof(Primitive);

				if(state.multiSample > 1)
				{
					Short x = Short((X[0] + 0xF) >> 4);

					For(Int y = yMin - 1, y < yMax + 1, y++)
					{
						*Pointer<Short>(leftEdge + y * sizeof(Primitive::Span)) = x;
						*Pointer<Short>(rightEdge + y * sizeof(Primitive::Span)) = x;
					}
				}

				Xq[n] = Xq[0];
				Yq[n] = Yq[0];

				// Rasterize
				{
					Int i = 0;

					Do
					{
						edge(primitive, Int(Xq[i + 1 - d]), Int(Yq[i + 1 - d]), Int(Xq[i + d]), Int(Yq[i + d]), q);

						i++;
					}
					Until(i >= n)
				}

				if(state.multiSample == 1)
				{
					For(yMin, yMin < yMax && *Pointer<Short>(leftEdge + yMin * sizeof(Primitive::Span)) == *Pointer<Short>(rightEdge + yMin * sizeof(Primitive::Span)), yMin++)
					{
						// Increments yMin
					}

					For(yMax, yMax > yMin && *Pointer<Short>(leftEdge + (yMax - 1) * sizeof(Primitive::Span)) == *Pointer<Short>(rightEdge + (yMax - 1) * sizeof(Primitive::Span)), yMax--)
					{
						// Decrements yMax
					}

					If(yMin == yMax)
					{
						Return(false);
					}

					*Pointer<Short>(leftEdge + (yMin - 1) * sizeof(Primitive::Span)) = *Pointer<Short>(leftEdge + yMin * sizeof(Primitive::Span));
					*Pointer<Short>(rightEdge + (yMin - 1) * sizeof(Primitive::Span)) = *Pointer<Short>(leftEdge + yMin * sizeof(Primitive::Span));
					*Pointer<Short>(leftEdge + yMax * sizeof(Primitive::Span)) = *Pointer<Short>(leftEdge + (yMax - 1) * sizeof(Primitive::Span));
					*Pointer<Short>(rightEdge + yMax * sizeof(Primitive::Span)) = *Pointer<Short>(leftEdge + (yMax - 1) * sizeof(Primitive::Span));
				}
			}

			*Pointer<Int>(primitive + OFFSET(Primitive,yMin)) = yMin;
			*Pointer<Int>(primitive + OFFSET(Primitive,yMax)) = yMax;

			// Sort by minimum y
			if(solidTriangle && logPrecision >= WHQL)
			{
				Float y0 = *Pointer<Float>(v0 + pos * 16 + 4);
				Float y1 = *Pointer<Float>(v1 + pos * 16 + 4);
				Float y2 = *Pointer<Float>(v2 + pos * 16 + 4);

				Float yMin = Min(Min(y0, y1), y2);

				conditionalRotate1(yMin == y1, v0, v1, v2);
				conditionalRotate2(yMin == y2, v0, v1, v2);
			}

			// Sort by maximum w
			if(solidTriangle)
			{
				Float w0 = *Pointer<Float>(v0 + pos * 16 + 12);
				Float w1 = *Pointer<Float>(v1 + pos * 16 + 12);
				Float w2 = *Pointer<Float>(v2 + pos * 16 + 12);

				Float wMax = Max(Max(w0, w1), w2);

				conditionalRotate1(wMax == w1, v0, v1, v2);
				conditionalRotate2(wMax == w2, v0, v1, v2);
			}

			Float4 p0 = *Pointer<Float4>(v0 + pos * 16, 16);
			Float4 p1 = *Pointer<Float4>(v1 + pos * 16, 16);
			Float4 p2 = *Pointer<Float4>(v2 + pos * 16, 16);

			Float w0 = p0.w;
			Float w1 = p1.w;
			Float w2 = p2.w;

			Float4 w012;

			w012.x = w0;
			w012.y = w1;
			w012.z = w2;
			w012.w = 1;

			Float rhw0 = *Pointer<Float>(v0 + OFFSET(Vertex,W));

			Int X0 = *Pointer<Int>(v0 + OFFSET(Vertex,X));
			Int X1 = *Pointer<Int>(v1 + OFFSET(Vertex,X));
			Int X2 = *Pointer<Int>(v2 + OFFSET(Vertex,X));

			Int Y0 = *Pointer<Int>(v0 + OFFSET(Vertex,Y));
			Int Y1 = *Pointer<Int>(v1 + OFFSET(Vertex,Y));
			Int Y2 = *Pointer<Int>(v2 + OFFSET(Vertex,Y));

			if(line)
			{
				X2 = X1 + Y1 - Y0;
				Y2 = Y1 + X0 - X1;
			}

			Float dx = Float(X0) * Float(1.0f / 16.0f);
			Float dy = Float(Y0) * Float(1.0f / 16.0f);

			X1 -= X0;
			Y1 -= Y0;

			X2 -= X0;
			Y2 -= Y0;

			Float x1 = w1 * Float(1.0f / 16.0f) * Float(X1);
			Float y1 = w1 * Float(1.0f / 16.0f) * Float(Y1);

			Float x2 = w2 * Float(1.0f / 16.0f) * Float(X2);
			Float y2 = w2 * Float(1.0f / 16.0f) * Float(Y2);

			Float a = x1 * y2 - x2 * y1;

			Float4 xQuad = Float4(0, 1, 0, 1) - Float4(dx);
			Float4 yQuad = Float4(0, 0, 1, 1) - Float4(dy);

			*Pointer<Float4>(primitive + OFFSET(Primitive,xQuad), 16) = xQuad;
			*Pointer<Float4>(primitive + OFFSET(Primitive,yQuad), 16) = yQuad;

			Float4 M[3];

			M[0] = Float4(0, 0, 0, 0);
			M[1] = Float4(0, 0, 0, 0);
			M[2] = Float4(0, 0, 0, 0);

			M[0].z = rhw0;

			If(a != Float(0.0f))
			{
				Float A = Float(1) / a;
				Float D = A * rhw0;

				M[0].x = (y1 * w2 - y2 * w1) * D;
				M[0].y = (x2 * w1 - x1 * w2) * D;
			//	M[0].z = rhw0;
			//	M[0].w = 0;

				M[1].x = y2 * A;
				M[1].y = -x2 * A;
			//	M[1].z = 0;
			//	M[1].w = 0;

				M[2].x = -y1 * A;
				M[2].y = x1 * A;
			//	M[2].z = 0;
			//	M[2].w = 0;
			}

			if(state.perspective)
			{
				Float4 ABC = M[0] + M[1] + M[2];

				Float4 A = ABC.x;
				Float4 B = ABC.y;
				Float4 C = ABC.z;

				*Pointer<Float4>(primitive + OFFSET(Primitive,w.A), 16) = A;
				*Pointer<Float4>(primitive + OFFSET(Primitive,w.B), 16) = B;
				*Pointer<Float4>(primitive + OFFSET(Primitive,w.C), 16) = C;
			}

			if(state.interpolateDepth)
			{
				Float z0 = *Pointer<Float>(v0 + OFFSET(Vertex,Z));
				Float z1 = *Pointer<Float>(v1 + OFFSET(Vertex,Z));
				Float z2 = *Pointer<Float>(v2 + OFFSET(Vertex,Z));

				z1 -= z0;
				z2 -= z0;

				Float4 A;
				Float4 B;
				Float4 C;

				if(!point)
				{
					Float x1 = Float(X1) * Float(1.0f / 16.0f);
					Float y1 = Float(Y1) * Float(1.0f / 16.0f);
					Float x2 = Float(X2) * Float(1.0f / 16.0f);
					Float y2 = Float(Y2) * Float(1.0f / 16.0f);

					Float D = *Pointer<Float>(data + OFFSET(DrawData,depthRange)) / (x1 * y2 - x2 * y1);

					Float a = (y2 * z1 - y1 * z2) * D;
					Float b = (x1 * z2 - x2 * z1) * D;

					A = Float4(a);
					B = Float4(b);
				}
				else
				{
					A = Float4(0, 0, 0, 0);
					B = Float4(0, 0, 0, 0);
				}

				*Pointer<Float4>(primitive + OFFSET(Primitive,z.A), 16) = A;
				*Pointer<Float4>(primitive + OFFSET(Primitive,z.B), 16) = B;

				Float c = z0;

				if(state.isDrawTriangle && state.slopeDepthBias)
				{
					Float bias = Max(Abs(Float(A.x)), Abs(Float(B.x)));
					bias *= *Pointer<Float>(data + OFFSET(DrawData,slopeDepthBias));

					if(complementaryDepthBuffer)
					{
						bias = -bias;
					}

					c += bias;
				}

				C = Float4(c * *Pointer<Float>(data + OFFSET(DrawData,depthRange)) + *Pointer<Float>(data + OFFSET(DrawData,depthNear)));

				*Pointer<Float4>(primitive + OFFSET(Primitive,z.C), 16) = C;
			}

			for(int interpolant = 0; interpolant < 11; interpolant++)
			{
				int componentCount = interpolant < 10 ? 4 : 1;   // Fog only has one component

				for(int component = 0; component < componentCount; component++)
				{
					int attribute = state.gradient[interpolant][component].attribute;
					bool flat = state.gradient[interpolant][component].flat;
					bool wrap = state.gradient[interpolant][component].wrap;

					if(attribute < 12)
					{
						setupGradient(primitive, tri, w012, M, v0, v1, v2, OFFSET(Vertex,v[attribute][component]), OFFSET(Primitive,V[interpolant][component]), flat, sprite, state.perspective, wrap, component);
					}
				}
			}

			Return(true);
		}

		routine = function(L"SetupRoutine");
	}

	void SetupRoutine::setupGradient(Pointer<Byte> &primitive, Pointer<Byte> &triangle, Float4 &w012, Float4 (&m)[3], Pointer<Byte> &v0, Pointer<Byte> &v1, Pointer<Byte> &v2, int attribute, int planeEquation, bool flat, bool sprite, bool perspective, bool wrap, int component)
	{
		Float4 i;

		if(!flat)
		{
			if(!sprite)
			{
				i.x = *Pointer<Float>(v0 + attribute);
				i.y = *Pointer<Float>(v1 + attribute);
				i.z = *Pointer<Float>(v2 + attribute);
				i.w = 0;
			}
			else
			{
				if(component == 0) i.x = Float(0.5f);
				if(component == 1) i.x = Float(0.5f);
				if(component == 2) i.x = Float(0.0f);
				if(component == 3) i.x = Float(1.0f);

				if(component == 0) i.y = Float(1.0f);
				if(component == 1) i.y = Float(0.5f);
				if(component == 2) i.y = Float(0.0f);
				if(component == 3) i.y = Float(1.0f);

				if(component == 0) i.z = Float(0.5f);
				if(component == 1) i.z = Float(0.0f);
				if(component == 2) i.z = Float(0.0f);
				if(component == 3) i.z = Float(1.0f);
				
				i.w = 0;
			}

			if(wrap)
			{
				Float m;

				m = *Pointer<Float>(v0 + attribute);
				m = Max(m, *Pointer<Float>(v1 + attribute));
				m = Max(m, *Pointer<Float>(v2 + attribute));
				m -= Float(0.5f);   // FIXME: m -= 0.5f;

				// FIXME: Vectorize
				If(Float(i.x) < m) i.x = Float(i.x) + Float(1.0f);
				If(Float(i.y) < m) i.y = Float(i.y) + Float(1.0f);
				If(Float(i.z) < m) i.z = Float(i.z) + Float(1.0f);
			}

			if(!perspective)
			{
				i *= w012;
			}

			Float4 A;
			Float4 B;
			Float4 C;

			A = i.xxxx;
			B = i.yyyy;
			C = i.zzzz;

			A *= m[0];
			B *= m[1];
			C *= m[2];

			C = A + B + C;

			A = C.xxxx;
			B = C.yyyy;
			C = C.zzzz;

			*Pointer<Float4>(primitive + planeEquation + 0, 16) = A;
			*Pointer<Float4>(primitive + planeEquation + 16, 16) = B;
			*Pointer<Float4>(primitive + planeEquation + 32, 16) = C;
		}
		else
		{
			Float C = *Pointer<Float>(triangle + OFFSET(Triangle,v0) + attribute);

			*Pointer<Float4>(primitive + planeEquation + 0, 16) = Float4(0, 0, 0, 0);
			*Pointer<Float4>(primitive + planeEquation + 16, 16) = Float4(0, 0, 0, 0);
			*Pointer<Float4>(primitive + planeEquation + 32, 16) = Float4(C);
		}
	}

	void SetupRoutine::edge(Pointer<Byte> &primitive, Int &X1, Int &Y1, Int &X2, Int &Y2, Int &q)
	{
		If(Y1 != Y2)
		{
			Bool swap = Y2 < Y1;

			Pointer<Byte> leftEdge = primitive + q * sizeof(Primitive) + OFFSET(Primitive,outline->left);
			Pointer<Byte> rightEdge = primitive + q * sizeof(Primitive) + OFFSET(Primitive,outline->right);
			Pointer<Byte> edge = IfThenElse(swap, rightEdge, leftEdge);

			Int X0 = X1;
			Int Y0 = Y1;
			X1 = IfThenElse(swap, X2, X1);
			X2 = IfThenElse(swap, X0, X2);
			Y1 = IfThenElse(swap, Y2, Y1);
			Y2 = IfThenElse(swap, Y0, Y2);

			Int y1 = (Y1 + 0x0000000F) >> 4;
			Int y2 = (Y2 + 0x0000000F) >> 4;

			If(y1 != y2)
			{
				// Deltas
				Int DX12 = X2 - X1;
				Int DY12 = Y2 - Y1;

				Int FDX12 = DX12 << 4;
				Int FDY12 = DY12 << 4;

				Int X = DX12 * (-Y1 & 0xF) + X1 * DY12;
				Int x = X / FDY12;     // Edge
				Int d = X % FDY12;     // Error-term
				Int ceil = -d >> 31;   // Ceiling division: remainder <= 0
				x -= ceil;
				d -= ceil & FDY12;
				
				Int Q = FDX12 / FDY12;   // Edge-step
				Int R = FDX12 % FDY12;   // Error-step
				Int floor = R >> 31;     // Flooring division: remainder >= 0
				Q += floor;
				R += floor & FDY12;

				Int D = FDY12;   // Error-overflow
				Int y = y1;

				Do
				{
					*Pointer<Short>(edge + y * sizeof(Primitive::Span)) = Short(x);

					x += Q;
					d += R;

					Int overflow = -d >> 31;
			
					d -= D & overflow;
					x -= overflow;

					y++;
				}
				Until(y >= y2)
			}
		}
	}

	void SetupRoutine::conditionalRotate1(Bool condition, Pointer<Byte> &v0, Pointer<Byte> &v1, Pointer<Byte> &v2)
	{
		#if 0   // Rely on LLVM optimization
			If(condition)
			{
				Pointer<Byte> vX;
			
				vX = v0;
				v0 = v1;
				v1 = v2;
				v2 = vX;
			}
		#else
			Pointer<Byte> vX = v0;
			v0 = IfThenElse(condition, v1, v0);
			v1 = IfThenElse(condition, v2, v1);
			v2 = IfThenElse(condition, vX, v2);
		#endif
	}

	void SetupRoutine::conditionalRotate2(Bool condition, Pointer<Byte> &v0, Pointer<Byte> &v1, Pointer<Byte> &v2)
	{
		#if 0   // Rely on LLVM optimization
			If(condition)
			{
				Pointer<Byte> vX;
			
				vX = v2;
				v2 = v1;
				v1 = v0;
				v0 = vX;
			}
		#else
			Pointer<Byte> vX = v2;
			v2 = IfThenElse(condition, v1, v2);
			v1 = IfThenElse(condition, v0, v1);
			v0 = IfThenElse(condition, vX, v0);
		#endif
	}

	Routine *SetupRoutine::getRoutine()
	{
		return routine;
	}
}