ppsspp/GPU/Software/Rasterizer.cpp

// Copyright (c) 2013- PPSSPP Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0 or later versions.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.

#include "base/basictypes.h"

#include "Common/ThreadPools.h"
#include "Core/Config.h"
#include "Core/MemMap.h"
#include "Core/Reporting.h"
#include "GPU/GPUState.h"

#include "GPU/Common/TextureDecoder.h"
#include "GPU/Software/SoftGpu.h"
#include "GPU/Software/Rasterizer.h"
#include "GPU/Software/Colors.h"

#include <algorithm>

extern FormatBuffer fb;
extern FormatBuffer depthbuf;

extern u32 clut[4096];

namespace Rasterizer {

//static inline int orient2d(const DrawingCoords& v0, const DrawingCoords& v1, const DrawingCoords& v2)
static inline int orient2d(const ScreenCoords& v0, const ScreenCoords& v1, const ScreenCoords& v2)
{
	return ((int)v1.x-(int)v0.x)*((int)v2.y-(int)v0.y) - ((int)v1.y-(int)v0.y)*((int)v2.x-(int)v0.x);
}

static inline int orient2dIncX(int dY01)
{
	return dY01;
}

static inline int orient2dIncY(int dX01)
{
	return -dX01;
}

template <unsigned int texel_size_bits>
static inline int GetPixelDataOffset(unsigned int row_pitch_bits, unsigned int u, unsigned int v)
{
	if (!gstate.isTextureSwizzled())
		return (v * (row_pitch_bits * texel_size_bits >> 6)) + (u * texel_size_bits >> 3);

	const int tile_size_bits = 32;
	const int tiles_in_block_horizontal = 4;
	const int tiles_in_block_vertical = 8;

	int texels_per_tile = tile_size_bits / texel_size_bits;
	int tile_u = u / texels_per_tile;
	int tile_idx = (v % tiles_in_block_vertical) * (tiles_in_block_horizontal) +
	// TODO: not sure if the *texel_size_bits/8 factor is correct
					(v / tiles_in_block_vertical) * ((row_pitch_bits*texel_size_bits/(8*tile_size_bits))*tiles_in_block_vertical) +
					(tile_u % tiles_in_block_horizontal) +
					(tile_u / tiles_in_block_horizontal) * (tiles_in_block_horizontal*tiles_in_block_vertical);

	return tile_idx * (tile_size_bits / 8) + ((u % texels_per_tile) * texel_size_bits) / 8;
}

static inline u32 LookupColor(unsigned int index, unsigned int level)
{
	const bool mipmapShareClut = gstate.isClutSharedForMipmaps();
	const int clutSharingOffset = mipmapShareClut ? 0 : level * 16;

	switch (gstate.getClutPaletteFormat()) {
	case GE_TFMT_5650:
		return DecodeRGB565(reinterpret_cast<u16*>(clut)[index + clutSharingOffset]);

	case GE_TFMT_5551:
		return DecodeRGBA5551(reinterpret_cast<u16*>(clut)[index + clutSharingOffset]);

	case GE_TFMT_4444:
		return DecodeRGBA4444(reinterpret_cast<u16*>(clut)[index + clutSharingOffset]);

	case GE_TFMT_8888:
		return DecodeRGBA8888(clut[index + clutSharingOffset]);

	default:
		ERROR_LOG_REPORT(G3D, "Software: Unsupported palette format: %x", gstate.getClutPaletteFormat());
		return 0;
	}
}

static inline void GetTexelCoordinates(int level, float s, float t, int& out_u, int& out_v)
{
	int width = 1 << (gstate.texsize[level] & 0xf);
	int height = 1 << ((gstate.texsize[level]>>8) & 0xf);

	int u = (int)(s * width);
	int v = (int)(t * height);

	if (gstate.isTexCoordClampedS()) {
		if (u >= width - 1)
			u = width - 1;
		else if (u < 0)
			u = 0;
	} else {
		u &= width - 1;
	}
	if (gstate.isTexCoordClampedT()) {
		if (v >= height - 1)
			v = height - 1;
		else if (v < 0)
			v = 0;
	} else {
		v &= height - 1;
	}

	out_u = u;
	out_v = v;
}

static inline void GetTexelCoordinatesQuad(int level, float in_s, float in_t, int u[4], int v[4], int &frac_u, int &frac_v)
{
	// 8 bits of fractional UV
	int width = 1 << (gstate.texsize[level] & 0xf);
	int height = 1 << ((gstate.texsize[level]>>8) & 0xf);

	int base_u = in_s * width * 256;
	int base_v = in_t * height * 256;

	frac_u = (int)(base_u) & 0xff;
	frac_v = (int)(base_v) & 0xff;

	base_u >>= 8;
	base_v >>= 8;

	// Need to generate and individually wrap/clamp the four sample coordinates. Ugh.

	if (gstate.isTexCoordClampedS()) {
		for (int i = 0; i < 4; i++) {
			int temp_u = base_u + (i & 1);
			if (temp_u > width - 1)
				temp_u = width - 1;
			else if (temp_u < 0)
				temp_u = 0;
			u[i] = temp_u;
		}
	} else {
		for (int i = 0; i < 4; i++) {
			u[i] = (base_u + (i & 1)) & (width - 1);
		}
	}
	if (gstate.isTexCoordClampedT()) {
		for (int i = 0; i < 4; i++) {
			int temp_v = base_v + ((i & 2) >> 1);
			if (temp_v > height - 1)
				temp_v = height - 1;
			else if (temp_v < 0)
				temp_v = 0;
			v[i] = temp_v;
		}
	} else {
		for (int i = 0; i < 4; i++) {
			v[i] = (base_v + ((i & 2) >> 1)) & (height - 1);
		}
	}
}

static inline void GetTexelCoordinatesThrough(int level, int s, int t, int& u, int& v)
{
	// Not actually sure which clamp/wrap modes should be applied. Let's just wrap for now.
	int width = 1 << (gstate.texsize[level] & 0xf);
	int height = 1 << ((gstate.texsize[level]>>8) & 0xf);

	// Wrap!
	u = ((unsigned int)(s) & (width - 1));
	v = ((unsigned int)(t) & (height - 1));
}

static inline void GetTextureCoordinates(const VertexData& v0, const VertexData& v1, const VertexData& v2, int w0, int w1, int w2, float& s, float& t)
{
	switch (gstate.getUVGenMode()) {
	case GE_TEXMAP_TEXTURE_COORDS:
	case GE_TEXMAP_UNKNOWN:
	case GE_TEXMAP_ENVIRONMENT_MAP:
		{
			// TODO: What happens if vertex has no texture coordinates?
			// Note that for environment mapping, texture coordinates have been calculated during lighting
			float q0 = 1.f / v0.clippos.w;
			float q1 = 1.f / v1.clippos.w;
			float q2 = 1.f / v2.clippos.w;
			float q = q0 * w0 + q1 * w1 + q2 * w2;
			s = (v0.texturecoords.s() * q0 * w0 + v1.texturecoords.s() * q1 * w1 + v2.texturecoords.s() * q2 * w2) / q;
			t = (v0.texturecoords.t() * q0 * w0 + v1.texturecoords.t() * q1 * w1 + v2.texturecoords.t() * q2 * w2) / q;
		}
		break;
	case GE_TEXMAP_TEXTURE_MATRIX:
		{
			// projection mapping, TODO: Move this code to TransformUnit!
			Vec3<float> source;
			switch (gstate.getUVProjMode()) {
			case GE_PROJMAP_POSITION:
				source = ((v0.modelpos * w0 + v1.modelpos * w1 + v2.modelpos * w2) / (w0+w1+w2));
				break;

			case GE_PROJMAP_UV:
				source = Vec3f((v0.texturecoords * w0 + v1.texturecoords * w1 + v2.texturecoords * w2) / (w0 + w1 + w2), 0.0f);
				break;

			default:
				ERROR_LOG_REPORT(G3D, "Software: Unsupported UV projection mode %x", gstate.getUVProjMode());
				break;
			}

			Mat3x3<float> tgen(gstate.tgenMatrix);
			Vec3<float> stq = tgen * source + Vec3<float>(gstate.tgenMatrix[9], gstate.tgenMatrix[10], gstate.tgenMatrix[11]);
			s = stq.x/stq.z;
			t = stq.y/stq.z;
		}
		break;
	default:
		ERROR_LOG_REPORT(G3D, "Software: Unsupported texture mapping mode %x!", gstate.getUVGenMode());
		break;
	}	
}

static inline u32 SampleNearest(int level, unsigned int u, unsigned int v, const u8 *srcptr, int texbufwidthbits)
{
	if (!srcptr)
		return 0;

	GETextureFormat texfmt = gstate.getTextureFormat();

	// TODO: Should probably check if textures are aligned properly...

	switch (texfmt) {
	case GE_TFMT_4444:
		srcptr += GetPixelDataOffset<16>(texbufwidthbits, u, v);
		return DecodeRGBA4444(*(const u16*)srcptr);
	
	case GE_TFMT_5551:
		srcptr += GetPixelDataOffset<16>(texbufwidthbits, u, v);
		return DecodeRGBA5551(*(const u16*)srcptr);

	case GE_TFMT_5650:
		srcptr += GetPixelDataOffset<16>(texbufwidthbits, u, v);
		return DecodeRGB565(*(const u16*)srcptr);

	case GE_TFMT_8888:
		srcptr += GetPixelDataOffset<32>(texbufwidthbits, u, v);
		return DecodeRGBA8888(*(const u32 *)srcptr);

	case GE_TFMT_CLUT32:
		{
			srcptr += GetPixelDataOffset<32>(texbufwidthbits, u, v);
			u32 val = srcptr[0] + (srcptr[1] << 8) + (srcptr[2] << 16) + (srcptr[3] << 24);
			return LookupColor(gstate.transformClutIndex(val), level);
		}
	case GE_TFMT_CLUT16:
		{
			srcptr += GetPixelDataOffset<16>(texbufwidthbits, u, v);
			u16 val = srcptr[0] + (srcptr[1] << 8);
			return LookupColor(gstate.transformClutIndex(val), level);
		}
	case GE_TFMT_CLUT8:
		{
			srcptr += GetPixelDataOffset<8>(texbufwidthbits, u, v);
			u8 val = *srcptr;
			return LookupColor(gstate.transformClutIndex(val), level);
		}
	case GE_TFMT_CLUT4:
		{
			srcptr += GetPixelDataOffset<4>(texbufwidthbits, u, v);
			u8 val = (u & 1) ? (srcptr[0] >> 4) : (srcptr[0] & 0xF);
			return LookupColor(gstate.transformClutIndex(val), level);
		}
	case GE_TFMT_DXT1:
		{
			const DXT1Block *block = (const DXT1Block *)srcptr + (v / 4) * (texbufwidthbits / 8 / 4) + (u / 4);
			u32 data[4 * 4];
			DecodeDXT1Block(data, block, 4);
			return DecodeRGBA8888(data[4 * (v % 4) + (u % 4)]);
		}
	case GE_TFMT_DXT3:
		{
			const DXT3Block *block = (const DXT3Block *)srcptr + (v / 4) * (texbufwidthbits / 8 / 4) + (u / 4);
			u32 data[4 * 4];
			DecodeDXT3Block(data, block, 4);
			return DecodeRGBA8888(data[4 * (v % 4) + (u % 4)]);
		}
	case GE_TFMT_DXT5:
		{
			const DXT5Block *block = (const DXT5Block *)srcptr + (v / 4) * (texbufwidthbits / 8 / 4) + (u / 4);
			u32 data[4 * 4];
			DecodeDXT5Block(data, block, 4);
			return DecodeRGBA8888(data[4 * (v % 4) + (u % 4)]);
		}
	default:
		ERROR_LOG_REPORT(G3D, "Software: Unsupported texture format: %x", texfmt);
		return 0;
	}
}

// NOTE: These likely aren't endian safe
static inline u32 GetPixelColor(int x, int y)
{
	switch (gstate.FrameBufFormat()) {
	case GE_FORMAT_565:
		return DecodeRGB565(fb.Get16(x, y, gstate.FrameBufStride()));

	case GE_FORMAT_5551:
		return DecodeRGBA5551(fb.Get16(x, y, gstate.FrameBufStride()));

	case GE_FORMAT_4444:
		return DecodeRGBA4444(fb.Get16(x, y, gstate.FrameBufStride()));

	case GE_FORMAT_8888:
		return fb.Get32(x, y, gstate.FrameBufStride());

	case GE_FORMAT_INVALID:
		_dbg_assert_msg_(G3D, false, "Software: invalid framebuf format.");
	}
	return 0;
}

static inline void SetPixelColor(int x, int y, u32 value)
{
	switch (gstate.FrameBufFormat()) {
	case GE_FORMAT_565:
		fb.Set16(x, y, gstate.FrameBufStride(), RGBA8888To565(value));
		break;

	case GE_FORMAT_5551:
		fb.Set16(x, y, gstate.FrameBufStride(), RGBA8888To5551(value));
		break;

	case GE_FORMAT_4444:
		fb.Set16(x, y, gstate.FrameBufStride(), RGBA8888To4444(value));
		break;

	case GE_FORMAT_8888:
		fb.Set32(x, y, gstate.FrameBufStride(), value);
		break;

	case GE_FORMAT_INVALID:
		_dbg_assert_msg_(G3D, false, "Software: invalid framebuf format.");
	}
}

static inline u16 GetPixelDepth(int x, int y)
{
	return depthbuf.Get16(x, y, gstate.DepthBufStride());
}

static inline void SetPixelDepth(int x, int y, u16 value)
{
	depthbuf.Set16(x, y, gstate.DepthBufStride(), value);
}

static inline u8 GetPixelStencil(int x, int y)
{
	if (gstate.FrameBufFormat() == GE_FORMAT_565) {
		// Always treated as 0 for comparison purposes.
		return 0;
	} else if (gstate.FrameBufFormat() == GE_FORMAT_5551) {
		return ((fb.Get16(x, y, gstate.FrameBufStride()) & 0x8000) != 0) ? 0xFF : 0;
	} else if (gstate.FrameBufFormat() == GE_FORMAT_4444) {
		return Convert4To8(fb.Get16(x, y, gstate.FrameBufStride()) >> 12);
	} else {
		return fb.Get32(x, y, gstate.FrameBufStride()) >> 24;
	}
}

static inline void SetPixelStencil(int x, int y, u8 value)
{
	// TODO: This seems like it maybe respects the alpha mask (at least in some scenarios?)

	if (gstate.FrameBufFormat() == GE_FORMAT_565) {
		// Do nothing
	} else if (gstate.FrameBufFormat() == GE_FORMAT_5551) {
		u16 pixel = fb.Get16(x, y, gstate.FrameBufStride()) & ~0x8000;
		pixel |= value != 0 ? 0x8000 : 0;
		fb.Set16(x, y, gstate.FrameBufStride(), pixel);
	} else if (gstate.FrameBufFormat() == GE_FORMAT_4444) {
		u16 pixel = fb.Get16(x, y, gstate.FrameBufStride()) & ~0xF000;
		pixel |= (u16)value << 12;
		fb.Set16(x, y, gstate.FrameBufStride(), pixel);
	} else {
		u32 pixel = fb.Get32(x, y, gstate.FrameBufStride()) & ~0xFF000000;
		pixel |= (u32)value << 24;
		fb.Set32(x, y, gstate.FrameBufStride(), pixel);
	}
}

static inline bool DepthTestPassed(int x, int y, u16 z)
{
	u16 reference_z = GetPixelDepth(x, y);

	switch (gstate.getDepthTestFunction()) {
	case GE_COMP_NEVER:
		return false;

	case GE_COMP_ALWAYS:
		return true;

	case GE_COMP_EQUAL:
		return (z == reference_z);

	case GE_COMP_NOTEQUAL:
		return (z != reference_z);

	case GE_COMP_LESS:
		return (z < reference_z);

	case GE_COMP_LEQUAL:
		return (z <= reference_z);

	case GE_COMP_GREATER:
		return (z > reference_z);

	case GE_COMP_GEQUAL:
		return (z >= reference_z);

	default:
		return 0;
	}
}

static inline bool IsRightSideOrFlatBottomLine(const Vec2<fixed16>& vertex, const Vec2<fixed16>& line1, const Vec2<fixed16>& line2)
{
	if (line1.y == line2.y) {
		// just check if vertex is above us => bottom line parallel to x-axis
		return vertex.y < line1.y;
	} else {
		// check if vertex is on our left => right side
		return vertex.x < line1.x + ((int)line2.x - (int)line1.x) * ((int)vertex.y - (int)line1.y) / ((int)line2.y - (int)line1.y);
	}
}

static inline bool StencilTestPassed(u8 stencil)
{
	// TODO: Does the masking logic make any sense?
	stencil &= gstate.getStencilTestMask();
	u8 ref = gstate.getStencilTestRef() & gstate.getStencilTestMask();
	switch (gstate.getStencilTestFunction()) {
		case GE_COMP_NEVER:
			return false;

		case GE_COMP_ALWAYS:
			return true;

		case GE_COMP_EQUAL:
			return ref == stencil;

		case GE_COMP_NOTEQUAL:
			return ref != stencil;

		case GE_COMP_LESS:
			return ref < stencil;

		case GE_COMP_LEQUAL:
			return ref <= stencil;

		case GE_COMP_GREATER:
			return ref > stencil;

		case GE_COMP_GEQUAL:
			return ref >= stencil;
	}
	return true;
}

static inline u8 ApplyStencilOp(int op, int x, int y)
{
	u8 old_stencil = GetPixelStencil(x, y); // TODO: Apply mask?
	u8 reference_stencil = gstate.getStencilTestRef(); // TODO: Apply mask?

	switch (op) {
		case GE_STENCILOP_KEEP:
			return old_stencil;

		case GE_STENCILOP_ZERO:
			return 0;

		case GE_STENCILOP_REPLACE:
			return reference_stencil;

		case GE_STENCILOP_INVERT:
			return ~old_stencil;

		case GE_STENCILOP_INCR:
			switch (gstate.FrameBufFormat()) {
			case GE_FORMAT_8888:
				if (old_stencil != 0xFF) {
					return old_stencil + 1;
				}
				return old_stencil;
			case GE_FORMAT_5551:
				return 0xFF;
			case GE_FORMAT_4444:
				if (old_stencil < 0xF0) {
					return old_stencil + 0x10;
				}
				return old_stencil;
			default:
				return old_stencil;
			}
			break;

		case GE_STENCILOP_DECR:
			switch (gstate.FrameBufFormat()) {
			case GE_FORMAT_4444:
				if (old_stencil >= 0x10)
					return old_stencil - 0x10;
				break;
			default:
				if (old_stencil != 0)
					return old_stencil - 1;
				return old_stencil;
			}
			break;
	}

	return old_stencil;
}

static inline u32 ApplyLogicOp(GELogicOp op, u32 old_color, u32 new_color)
{
	switch (op) {
	case GE_LOGIC_CLEAR:
		new_color = 0;
		break;

	case GE_LOGIC_AND:
		new_color = new_color & old_color;
		break;

	case GE_LOGIC_AND_REVERSE:
		new_color = new_color & ~old_color;
		break;

	case GE_LOGIC_COPY:
		//new_color = new_color;
		break;

	case GE_LOGIC_AND_INVERTED:
		new_color = ~new_color & old_color;
		break;

	case GE_LOGIC_NOOP:
		new_color = old_color;
		break;

	case GE_LOGIC_XOR:
		new_color = new_color ^ old_color;
		break;

	case GE_LOGIC_OR:
		new_color = new_color | old_color;
		break;

	case GE_LOGIC_NOR:
		new_color = ~(new_color | old_color);
		break;

	case GE_LOGIC_EQUIV:
		new_color = ~(new_color ^ old_color);
		break;

	case GE_LOGIC_INVERTED:
		new_color = ~old_color;
		break;

	case GE_LOGIC_OR_REVERSE:
		new_color = new_color | ~old_color;
		break;

	case GE_LOGIC_COPY_INVERTED:
		new_color = ~new_color;
		break;

	case GE_LOGIC_OR_INVERTED:
		new_color = ~new_color | old_color;
		break;

	case GE_LOGIC_NAND:
		new_color = ~(new_color & old_color);
		break;

	case GE_LOGIC_SET:
		new_color = 0xFFFFFFFF;
		break;
	}

	return new_color;
}

static inline Vec4<int> GetTextureFunctionOutput(const Vec3<int>& prim_color_rgb, int prim_color_a, const Vec4<int>& texcolor)
{
	Vec3<int> out_rgb;
	int out_a;

	bool rgba = gstate.isTextureAlphaUsed();

	switch (gstate.getTextureFunction()) {
	case GE_TEXFUNC_MODULATE:
		out_rgb = prim_color_rgb * texcolor.rgb() / 255;
		out_a = (rgba) ? (prim_color_a * texcolor.a() / 255) : prim_color_a;
		break;

	case GE_TEXFUNC_DECAL:
	{
		int t = (rgba) ? texcolor.a() : 255;
		int invt = (rgba) ? 255 - t : 0;
		out_rgb = (prim_color_rgb * invt + texcolor.rgb() * t) / 255;
		out_a = prim_color_a;
		break;
	}

	case GE_TEXFUNC_BLEND:
	{
		const Vec3<int> const255(255, 255, 255);
		const Vec3<int> texenv(gstate.getTextureEnvColR(), gstate.getTextureEnvColG(), gstate.getTextureEnvColB());
		out_rgb = ((const255 - texcolor.rgb()) * prim_color_rgb + texcolor.rgb() * texenv) / 255;
		out_a = prim_color_a * ((rgba) ? texcolor.a() : 255) / 255;
		break;
	}

	case GE_TEXFUNC_REPLACE:
		out_rgb = texcolor.rgb();
		out_a = (rgba) ? texcolor.a() : prim_color_a;
		break;

	case GE_TEXFUNC_ADD:
		out_rgb = prim_color_rgb + texcolor.rgb();
		if (out_rgb.r() > 255) out_rgb.r() = 255;
		if (out_rgb.g() > 255) out_rgb.g() = 255;
		if (out_rgb.b() > 255) out_rgb.b() = 255;
		out_a = prim_color_a * ((rgba) ? texcolor.a() : 255) / 255;
		break;

	default:
		ERROR_LOG_REPORT(G3D, "Software: Unknown texture function %x", gstate.getTextureFunction());
		out_rgb = Vec3<int>::AssignToAll(0);
		out_a = 0;
	}

	return Vec4<int>(out_rgb.r(), out_rgb.g(), out_rgb.b(), out_a);
}

static inline bool ColorTestPassed(Vec3<int> color)
{
	const u32 mask = gstate.getColorTestMask();
	const u32 c = color.ToRGB() & mask;
	const u32 ref = gstate.getColorTestRef() & mask;
	switch (gstate.getColorTestFunction()) {
		case GE_COMP_NEVER:
			return false;

		case GE_COMP_ALWAYS:
			return true;

		case GE_COMP_EQUAL:
			return c == ref;

		case GE_COMP_NOTEQUAL:
			return c != ref;

		default:
			ERROR_LOG_REPORT(G3D, "Software: Invalid colortest function: %d", gstate.getColorTestFunction());
			break;
	}
	return true;
}

static inline bool AlphaTestPassed(int alpha)
{
	const u8 mask = gstate.getAlphaTestMask() & 0xFF;
	const u8 ref = gstate.getAlphaTestRef() & mask;
	alpha &= mask;

	switch (gstate.getAlphaTestFunction()) {
		case GE_COMP_NEVER:
			return false;

		case GE_COMP_ALWAYS:
			return true;

		case GE_COMP_EQUAL:
			return (alpha == ref);

		case GE_COMP_NOTEQUAL:
			return (alpha != ref);

		case GE_COMP_LESS:
			return (alpha < ref);

		case GE_COMP_LEQUAL:
			return (alpha <= ref);

		case GE_COMP_GREATER:
			return (alpha > ref);

		case GE_COMP_GEQUAL:
			return (alpha >= ref);
	}
	return true;
}

static inline Vec3<int> GetSourceFactor(int source_a, const Vec4<int>& dst)
{
	switch (gstate.getBlendFuncA()) {
	case GE_SRCBLEND_DSTCOLOR:
		return dst.rgb();

	case GE_SRCBLEND_INVDSTCOLOR:
		return Vec3<int>::AssignToAll(255) - dst.rgb();

	case GE_SRCBLEND_SRCALPHA:
		return Vec3<int>::AssignToAll(source_a);

	case GE_SRCBLEND_INVSRCALPHA:
		return Vec3<int>::AssignToAll(255 - source_a);

	case GE_SRCBLEND_DSTALPHA:
		return Vec3<int>::AssignToAll(dst.a());

	case GE_SRCBLEND_INVDSTALPHA:
		return Vec3<int>::AssignToAll(255 - dst.a());

	case GE_SRCBLEND_DOUBLESRCALPHA:
		return Vec3<int>::AssignToAll(2 * source_a);

	case GE_SRCBLEND_DOUBLEINVSRCALPHA:
		return Vec3<int>::AssignToAll(255 - 2 * source_a);

	case GE_SRCBLEND_DOUBLEDSTALPHA:
		return Vec3<int>::AssignToAll(2 * dst.a());

	case GE_SRCBLEND_DOUBLEINVDSTALPHA:
		// TODO: Clamping?
		return Vec3<int>::AssignToAll(255 - 2 * dst.a());

	case GE_SRCBLEND_FIXA:
		return Vec4<int>::FromRGBA(gstate.getFixA()).rgb();

	default:
		ERROR_LOG_REPORT(G3D, "Software: Unknown source factor %x", gstate.getBlendFuncA());
		return Vec3<int>();
	}
}

static inline Vec3<int> GetDestFactor(const Vec3<int>& source_rgb, int source_a, const Vec4<int>& dst)
{
	switch (gstate.getBlendFuncB()) {
	case GE_DSTBLEND_SRCCOLOR:
		return source_rgb;

	case GE_DSTBLEND_INVSRCCOLOR:
		return Vec3<int>::AssignToAll(255) - source_rgb;

	case GE_DSTBLEND_SRCALPHA:
		return Vec3<int>::AssignToAll(source_a);

	case GE_DSTBLEND_INVSRCALPHA:
		return Vec3<int>::AssignToAll(255 - source_a);

	case GE_DSTBLEND_DSTALPHA:
		return Vec3<int>::AssignToAll(dst.a());

	case GE_DSTBLEND_INVDSTALPHA:
		return Vec3<int>::AssignToAll(255 - dst.a());

	case GE_DSTBLEND_DOUBLESRCALPHA:
		return Vec3<int>::AssignToAll(2 * source_a);

	case GE_DSTBLEND_DOUBLEINVSRCALPHA:
		return Vec3<int>::AssignToAll(255 - 2 * source_a);

	case GE_DSTBLEND_DOUBLEDSTALPHA:
		return Vec3<int>::AssignToAll(2 * dst.a());

	case GE_DSTBLEND_DOUBLEINVDSTALPHA:
		return Vec3<int>::AssignToAll(255 - 2 * dst.a());

	case GE_DSTBLEND_FIXB:
		return Vec4<int>::FromRGBA(gstate.getFixB()).rgb();

	default:
		ERROR_LOG_REPORT(G3D, "Software: Unknown dest factor %x", gstate.getBlendFuncB());
		return Vec3<int>();
	}
}

static inline Vec3<int> AlphaBlendingResult(const Vec3<int>& source_rgb, int source_a, const Vec4<int> dst)
{
	Vec3<int> srcfactor = GetSourceFactor(source_a, dst);
	Vec3<int> dstfactor = GetDestFactor(source_rgb, source_a, dst);

	switch (gstate.getBlendEq()) {
	case GE_BLENDMODE_MUL_AND_ADD:
		return (source_rgb * srcfactor + dst.rgb() * dstfactor) / 255;

	case GE_BLENDMODE_MUL_AND_SUBTRACT:
		return (source_rgb * srcfactor - dst.rgb() * dstfactor) / 255;

	case GE_BLENDMODE_MUL_AND_SUBTRACT_REVERSE:
		return (dst.rgb() * dstfactor - source_rgb * srcfactor) / 255;

	case GE_BLENDMODE_MIN:
		return Vec3<int>(std::min(source_rgb.r(), dst.r()),
						std::min(source_rgb.g(), dst.g()),
						std::min(source_rgb.b(), dst.b()));

	case GE_BLENDMODE_MAX:
		return Vec3<int>(std::max(source_rgb.r(), dst.r()),
						std::max(source_rgb.g(), dst.g()),
						std::max(source_rgb.b(), dst.b()));

	case GE_BLENDMODE_ABSDIFF:
		return Vec3<int>(::abs(source_rgb.r() - dst.r()),
						::abs(source_rgb.g() - dst.g()),
						::abs(source_rgb.b() - dst.b()));

	default:
		ERROR_LOG_REPORT(G3D, "Software: Unknown blend function %x", gstate.getBlendEq());
		return Vec3<int>();
	}
}

template <bool clearMode>
inline void DrawSinglePixel(const DrawingCoords &p, u16 z, Vec3<int> prim_color_rgb, int prim_color_a) {
	// Depth range test
	// TODO: Clear mode?
	if (!gstate.isModeThrough())
		if (z < gstate.getDepthRangeMin() || z > gstate.getDepthRangeMax())
			return;

	if (gstate.isColorTestEnabled() && !clearMode)
		if (!ColorTestPassed(prim_color_rgb))
			return;

	// TODO: Does a need to be clamped?
	if (gstate.isAlphaTestEnabled() && !clearMode)
		if (!AlphaTestPassed(prim_color_a))
			return;

	// In clear mode, it uses the alpha color as stencil.
	u8 stencil = clearMode ? prim_color_a : GetPixelStencil(p.x, p.y);
	// TODO: Is it safe to ignore gstate.isDepthTestEnabled() when clear mode is enabled?
	if (!clearMode && (gstate.isStencilTestEnabled() || gstate.isDepthTestEnabled())) {
		if (gstate.isStencilTestEnabled() && !StencilTestPassed(stencil)) {
			stencil = ApplyStencilOp(gstate.getStencilOpSFail(), p.x, p.y);
			SetPixelStencil(p.x, p.y, stencil);
			return;
		}

		// Also apply depth at the same time.  If disabled, same as passing.
		if (gstate.isDepthTestEnabled() && !DepthTestPassed(p.x, p.y, z)) {
			if (gstate.isStencilTestEnabled()) {
				stencil = ApplyStencilOp(gstate.getStencilOpZFail(), p.x, p.y);
				SetPixelStencil(p.x, p.y, stencil);
			}
			return;
		} else if (gstate.isStencilTestEnabled()) {
			stencil = ApplyStencilOp(gstate.getStencilOpZPass(), p.x, p.y);
		}

		if (gstate.isDepthTestEnabled() && gstate.isDepthWriteEnabled()) {
			SetPixelDepth(p.x, p.y, z);
		}
	} else if (clearMode && gstate.isClearModeDepthMask()) {
		SetPixelDepth(p.x, p.y, z);
	}

	// Doubling happens only when texturing is enabled, and after tests.
	if (gstate.isTextureMapEnabled() && gstate.isColorDoublingEnabled() && !clearMode) {
		// TODO: Does this need to be clamped before blending?
		prim_color_rgb *= 2;
	}

	if (gstate.isAlphaBlendEnabled() && !clearMode) {
		Vec4<int> dst = Vec4<int>::FromRGBA(GetPixelColor(p.x, p.y));
		prim_color_rgb = AlphaBlendingResult(prim_color_rgb, prim_color_a, dst);
	}

	if (!clearMode)
		prim_color_rgb = prim_color_rgb.Clamp(0, 255);

	u32 new_color = Vec4<int>(prim_color_rgb.r(), prim_color_rgb.g(), prim_color_rgb.b(), stencil).ToRGBA();
	u32 old_color = GetPixelColor(p.x, p.y);

	// TODO: Is alpha blending still performed if logic ops are enabled?
	if (gstate.isLogicOpEnabled() && !clearMode) {
		// Logic ops don't affect stencil.
		new_color = (stencil << 24) | (ApplyLogicOp(gstate.getLogicOp(), old_color, new_color) & 0x00FFFFFF);
	}

	if (clearMode) {
		new_color = (new_color & ~gstate.getClearModeColorMask()) | (old_color & gstate.getClearModeColorMask());
	} else {
		new_color = (new_color & ~gstate.getColorMask()) | (old_color & gstate.getColorMask());
	}

	// TODO: Dither before or inside SetPixelColor
	SetPixelColor(p.x, p.y, new_color);
}

inline void ApplyTexturing(Vec3<int> &prim_color_rgb, int &prim_color_a, float s, float t, int maxTexLevel, int magFilt, u8 *texptr[], int texbufwidthbits[]) {
	int u[4] = {0}, v[4] = {0};   // 1.23.8 fixed point
	int frac_u, frac_v;

	int texlevel = 0;

	bool bilinear = magFilt != 0;
	// bilinear = false;

	if (gstate.isModeThrough()) {
		int u_texel = s * 256;
		int v_texel = t * 256;
		frac_u = u_texel & 0xff;
		frac_v = v_texel & 0xff;
		u_texel >>= 8;
		v_texel >>= 8;

		// we need to compute UV for a quad of pixels together in order to get the mipmap deltas :(
		// texlevel = x

		if (texlevel > maxTexLevel)
			texlevel = maxTexLevel;

		GetTexelCoordinatesThrough(texlevel, u_texel, v_texel, u[0], v[0]);
		if (bilinear) {
			GetTexelCoordinatesThrough(texlevel, u_texel + 1, v_texel, u[1], v[1]);
			GetTexelCoordinatesThrough(texlevel, u_texel, v_texel + 1, u[2], v[2]);
			GetTexelCoordinatesThrough(texlevel, u_texel + 1, v_texel + 1, u[3], v[3]);
		}
	} else {
		// we need to compute UV for a quad of pixels together in order to get the mipmap deltas :(
		// texlevel = x

		if (texlevel > maxTexLevel)
			texlevel = maxTexLevel;

		if (bilinear) {
			GetTexelCoordinatesQuad(texlevel, s, t, u, v, frac_u, frac_v);
		} else {
			GetTexelCoordinates(texlevel, s, t, u[0], v[0]);
		}
	}

	Vec4<int> texcolor;
	int bufwbits = texbufwidthbits[texlevel];
	const u8 *tptr = texptr[texlevel];
	if (!bilinear) {
		// Nearest filtering only. Round texcoords or just chop bits?
		texcolor = Vec4<int>::FromRGBA(SampleNearest(texlevel, u[0], v[0], tptr, bufwbits));
	} else {
		Vec4<int> texcolor_tl = Vec4<int>::FromRGBA(SampleNearest(texlevel, u[0], v[0], tptr, bufwbits));
		Vec4<int> texcolor_tr = Vec4<int>::FromRGBA(SampleNearest(texlevel, u[1], v[1], tptr, bufwbits));
		Vec4<int> texcolor_bl = Vec4<int>::FromRGBA(SampleNearest(texlevel, u[2], v[2], tptr, bufwbits));
		Vec4<int> texcolor_br = Vec4<int>::FromRGBA(SampleNearest(texlevel, u[3], v[3], tptr, bufwbits));
		// 0x100 causes a slight bias to tl, but without it we'd have to divide by 255 * 255.
		Vec4<int> t = texcolor_tl * (0x100 - frac_u) + texcolor_tr * frac_u;
		Vec4<int> b = texcolor_bl * (0x100 - frac_u) + texcolor_br * frac_u;
		texcolor = (t * (0x100 - frac_v) + b * frac_v) / (256 * 256);
	}
	Vec4<int> out = GetTextureFunctionOutput(prim_color_rgb, prim_color_a, texcolor);
	prim_color_rgb = out.rgb();
	prim_color_a = out.a();
}

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)
{
	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);
	float texScaleU = getFloat24(gstate.texscaleu);
	float texScaleV = getFloat24(gstate.texscalev);
	float texOffsetU = getFloat24(gstate.texoffsetu);
	float texOffsetV = getFloat24(gstate.texoffsetv);

	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;

	int texbufwidthbits[8] = {0};

	int maxTexLevel = (gstate.texmode >> 16) & 7;
	u8 *texptr[8] = {NULL};

	int magFilt = (gstate.texfilter>>8) & 1;
	if (g_Config.iTexFiltering > 1) {
		if (g_Config.iTexFiltering == 2) {
			magFilt = 0;
		} else if (g_Config.iTexFiltering == 3) {
			magFilt = 1;
		}
	}
	if ((gstate.texfilter & 4) == 0) {
		// No mipmapping enabled
		maxTexLevel = 0;
	}

	if (gstate.isTextureMapEnabled() && !clearMode) {
		// TODO: Always using level 0.
		GETextureFormat texfmt = gstate.getTextureFormat();
		for (int i = 0; i <= maxTexLevel; i++) {
			u32 texaddr = gstate.getTextureAddress(i);
			texbufwidthbits[i] = GetTextureBufw(i, texaddr, texfmt) * 8;
			texptr[i] = Memory::GetPointer(texaddr);
		}
	}

	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);

	w0_base += orient2dIncY(d12.x) * 16 * y1;
	w1_base += orient2dIncY(-d02.x) * 16 * y1;
	w2_base += orient2dIncY(d01.x) * 16 * y1;

	// 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;

		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) {

			// If p is on or inside all edges, render pixel
			// TODO: Should we render if the pixel is both on the left and the right side? (i.e. degenerated triangle)
			if (w0 + bias0 >= 0 && w1 + bias1 >= 0 && w2 + bias2 >= 0) {
				// TODO: Check if this check is still necessary
				if (w0 == 0 && w1 == 0 && w2 == 0)
					continue;

				float wsum = 1.0f / (w0 + w1 + w2);

				Vec3<int> prim_color_rgb(0, 0, 0);
				int prim_color_a = 0;
				Vec3<int> sec_color(0, 0, 0);
				if (gstate.getShadeMode() == GE_SHADE_GOURAUD && !clearMode) {
					// NOTE: When not casting color0 and color1 to float vectors, this code suffers from severe overflow issues.
					// Not sure if that should be regarded as a bug or if casting to float is a valid fix.
					// TODO: Is that the correct way to interpolate?
					prim_color_rgb = ((v0.color0.rgb().Cast<float>() * w0 +
									v1.color0.rgb().Cast<float>() * w1 +
									v2.color0.rgb().Cast<float>() * w2) * wsum).Cast<int>();
					prim_color_a = (int)(((float)v0.color0.a() * w0 + (float)v1.color0.a() * w1 + (float)v2.color0.a() * w2) * wsum);
					sec_color = ((v0.color1.Cast<float>() * w0 +
									v1.color1.Cast<float>() * w1 +
									v2.color1.Cast<float>() * w2) * wsum).Cast<int>();
				} else {
					prim_color_rgb = v2.color0.rgb();
					prim_color_a = v2.color0.a();
					sec_color = v2.color1;
				}

				if (gstate.isTextureMapEnabled() && !clearMode) {
					if (gstate.isModeThrough()) {
						// TODO: Is it really this simple?
						float s = ((v0.texturecoords.s() * w0 + v1.texturecoords.s() * w1 + v2.texturecoords.s() * w2) * wsum);
						float t = ((v0.texturecoords.t() * w0 + v1.texturecoords.t() * w1 + v2.texturecoords.t() * w2) * wsum);
						ApplyTexturing(prim_color_rgb, prim_color_a, s, t, maxTexLevel, magFilt, texptr, texbufwidthbits);
					} else {
						float s = 0, t = 0;
						GetTextureCoordinates(v0, v1, v2, w0, w1, w2, s, t);
						s = s * texScaleU + texOffsetU;
						t = t * texScaleV + texOffsetV;
						ApplyTexturing(prim_color_rgb, prim_color_a, s, t, maxTexLevel, magFilt, texptr, texbufwidthbits);
					}
				}

				if (!clearMode)
					prim_color_rgb += sec_color;

				// TODO: Fogging

				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);

				DrawSinglePixel<clearMode>(p, z, prim_color_rgb, prim_color_a);
			}
		}
	}
}

// Draws triangle, vertices specified in counter-clockwise direction
void DrawTriangle(const VertexData& v0, const VertexData& v1, const VertexData& v2)
{
	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);

	// Drop primitives which are not in CCW order by checking the cross product
	if (d01.x * d02.y - d01.y * d02.x < 0)
		return;

	// Is the division and multiplication just &= ~0xF ?
	int minX = std::min(std::min(v0.screenpos.x, v1.screenpos.x), v2.screenpos.x) / 16 * 16;
	int minY = std::min(std::min(v0.screenpos.y, v1.screenpos.y), v2.screenpos.y) / 16 * 16;
	int maxX = std::max(std::max(v0.screenpos.x, v1.screenpos.x), v2.screenpos.x) / 16 * 16;
	int maxY = std::max(std::max(v0.screenpos.y, v1.screenpos.y), v2.screenpos.y) / 16 * 16;

	DrawingCoords scissorTL(gstate.getScissorX1(), gstate.getScissorY1(), 0);
	DrawingCoords scissorBR(gstate.getScissorX2(), gstate.getScissorY2(), 0);
	minX = std::max(minX, (int)TransformUnit::DrawingToScreen(scissorTL).x);
	maxX = std::min(maxX, (int)TransformUnit::DrawingToScreen(scissorBR).x);
	minY = std::max(minY, (int)TransformUnit::DrawingToScreen(scissorTL).y);
	maxY = std::min(maxY, (int)TransformUnit::DrawingToScreen(scissorBR).y);

	int range = (maxY - minY) / 16 + 1;
	if (gstate.isModeClear())
		GlobalThreadPool::Loop(std::bind(&DrawTriangleSlice<true>, v0, v1, v2, minX, minY, maxX, maxY, placeholder::_1, placeholder::_2), 0, range);
	else
		GlobalThreadPool::Loop(std::bind(&DrawTriangleSlice<false>, v0, v1, v2, minX, minY, maxX, maxY, placeholder::_1, placeholder::_2), 0, range);
}

void DrawPoint(const VertexData &v0)
{
	ScreenCoords pos = v0.screenpos;
	Vec3<int> prim_color_rgb = v0.color0.rgb();
	int prim_color_a = v0.color0.a();
	Vec3<int> sec_color = v0.color1;
	// TODO: UVGenMode?
	float s = v0.texturecoords.s();
	float t = v0.texturecoords.t();

	ScreenCoords scissorTL(TransformUnit::DrawingToScreen(DrawingCoords(gstate.getScissorX1(), gstate.getScissorY1(), 0)));
	ScreenCoords scissorBR(TransformUnit::DrawingToScreen(DrawingCoords(gstate.getScissorX2(), gstate.getScissorY2(), 0)));

	if (pos.x < scissorTL.x || pos.y < scissorTL.y || pos.x >= scissorBR.x || pos.y >= scissorBR.y)
		return;

	bool clearMode = gstate.isModeClear();

	if (gstate.isTextureMapEnabled() && !clearMode) {
		int texbufwidthbits[8] = {0};

		int maxTexLevel = (gstate.texmode >> 16) & 7;
		u8 *texptr[8] = {NULL};

		int magFilt = (gstate.texfilter>>8) & 1;
		if (g_Config.iTexFiltering > 1) {
			if (g_Config.iTexFiltering == 2) {
				magFilt = 0;
			} else if (g_Config.iTexFiltering == 3) {
				magFilt = 1;
			}
		}
		if ((gstate.texfilter & 4) == 0) {
			// No mipmapping enabled
			maxTexLevel = 0;
		}

		if (gstate.isTextureMapEnabled() && !clearMode) {
			// TODO: Always using level 0.
			maxTexLevel = 0;
			GETextureFormat texfmt = gstate.getTextureFormat();
			for (int i = 0; i <= maxTexLevel; i++) {
				u32 texaddr = gstate.getTextureAddress(i);
				texbufwidthbits[i] = GetTextureBufw(i, texaddr, texfmt) * 8;
				texptr[i] = Memory::GetPointer(texaddr);
			}
		}

		if (gstate.isModeThrough()) {
			// TODO: Is it really this simple?
			ApplyTexturing(prim_color_rgb, prim_color_a, s, t, maxTexLevel, magFilt, texptr, texbufwidthbits);
		} else {
			float texScaleU = getFloat24(gstate.texscaleu);
			float texScaleV = getFloat24(gstate.texscalev);
			float texOffsetU = getFloat24(gstate.texoffsetu);
			float texOffsetV = getFloat24(gstate.texoffsetv);

			s = s * texScaleU + texOffsetU;
			t = t * texScaleV + texOffsetV;
			ApplyTexturing(prim_color_rgb, prim_color_a, s, t, maxTexLevel, magFilt, texptr, texbufwidthbits);
		}
	}

	if (!clearMode)
		prim_color_rgb += sec_color;

	ScreenCoords pprime = pos;

	// TODO: Fogging
	DrawingCoords p = TransformUnit::ScreenToDrawing(pprime);
	u16 z = pos.z;

	if (clearMode) {
		DrawSinglePixel<true>(p, z, prim_color_rgb, prim_color_a);
	} else {
		DrawSinglePixel<false>(p, z, prim_color_rgb, prim_color_a);
	}
}

void DrawLine(const VertexData &v0, const VertexData &v1)
{
	// TODO: Use a proper line drawing algorithm that handles fractional endpoints correctly.
	Vec3<int> a(v0.screenpos.x, v0.screenpos.y, v0.screenpos.z);
	Vec3<int> b(v1.screenpos.x, v1.screenpos.y, v0.screenpos.z);

	int dx = b.x - a.x;
	int dy = b.y - a.y;
	int dz = b.z - a.z;

	int steps;
	if (abs(dx) < abs(dy))
		steps = dy / 16;
	else
		steps = dx / 16;

	float xinc = (float)dx / steps;
	float yinc = (float)dy / steps;
	float zinc = (float)dz / steps;

	ScreenCoords scissorTL(TransformUnit::DrawingToScreen(DrawingCoords(gstate.getScissorX1(), gstate.getScissorY1(), 0)));
	ScreenCoords scissorBR(TransformUnit::DrawingToScreen(DrawingCoords(gstate.getScissorX2(), gstate.getScissorY2(), 0)));
	bool clearMode = gstate.isModeClear();

	int texbufwidthbits[8] = {0};

	int maxTexLevel = (gstate.texmode >> 16) & 7;
	u8 *texptr[8] = {NULL};

	int magFilt = (gstate.texfilter>>8) & 1;
	if (g_Config.iTexFiltering > 1) {
		if (g_Config.iTexFiltering == 2) {
			magFilt = 0;
		} else if (g_Config.iTexFiltering == 3) {
			magFilt = 1;
		}
	}
	if ((gstate.texfilter & 4) == 0) {
		// No mipmapping enabled
		maxTexLevel = 0;
	}

	if (gstate.isTextureMapEnabled() && !clearMode) {
		// TODO: Always using level 0.
		GETextureFormat texfmt = gstate.getTextureFormat();
		for (int i = 0; i <= maxTexLevel; i++) {
			u32 texaddr = gstate.getTextureAddress(i);
			texbufwidthbits[i] = GetTextureBufw(i, texaddr, texfmt) * 8;
			texptr[i] = Memory::GetPointer(texaddr);
		}
	}

	float texScaleU = getFloat24(gstate.texscaleu);
	float texScaleV = getFloat24(gstate.texscalev);
	float texOffsetU = getFloat24(gstate.texoffsetu);
	float texOffsetV = getFloat24(gstate.texoffsetv);

	float x = a.x;
	float y = a.y;
	float z = a.z;
	const int steps1 = steps == 0 ? 1 : steps;
	for (int i = 0; i <= steps; i++) {
		if (x < scissorTL.x || y < scissorTL.y || x >= scissorBR.x || y >= scissorBR.y)
			continue;

		Vec4<int> c0 = (v0.color0 * (steps - i) + v1.color0 * i) / steps1;
		Vec3<int> sec_color = (v0.color1 * (steps - i) + v1.color1 * i) / steps1;
		// TODO: UVGenMode?
		Vec2<float> tc = (v0.texturecoords * (float)(steps - i) + v1.texturecoords * (float)i) / steps1;
		Vec3<int> prim_color_rgb = c0.rgb();
		int prim_color_a = c0.a();
		float s = tc.s();
		float t = tc.t();

		if (gstate.isTextureMapEnabled() && !clearMode) {
			if (gstate.isModeThrough()) {
				// TODO: Is it really this simple?
				ApplyTexturing(prim_color_rgb, prim_color_a, s, t, maxTexLevel, magFilt, texptr, texbufwidthbits);
			} else {
				s = s * texScaleU + texOffsetU;
				t = t * texScaleV + texOffsetV;
				ApplyTexturing(prim_color_rgb, prim_color_a, s, t, maxTexLevel, magFilt, texptr, texbufwidthbits);
			}
		}

		if (!clearMode)
			prim_color_rgb += sec_color;

		ScreenCoords pprime = ScreenCoords(x, y, z);

		// TODO: Fogging
		DrawingCoords p = TransformUnit::ScreenToDrawing(pprime);

		if (clearMode) {
			DrawSinglePixel<true>(p, z, prim_color_rgb, prim_color_a);
		} else {
			DrawSinglePixel<false>(p, z, prim_color_rgb, prim_color_a);
		}

		x = x + xinc;
		y = y + yinc;
		z = z + zinc;
	}
}

bool GetCurrentStencilbuffer(GPUDebugBuffer &buffer)
{
	int w = gstate.getRegionX2() - gstate.getRegionX1() + 1;
	int h = gstate.getRegionY2() - gstate.getRegionY1() + 1;
	buffer.Allocate(w, h, GPU_DBG_FORMAT_8BIT);

	u8 *row = buffer.GetData();
	for (int y = gstate.getRegionY1(); y <= gstate.getRegionY2(); ++y) {
		for (int x = gstate.getRegionX1(); x <= gstate.getRegionX2(); ++x) {
			row[x - gstate.getRegionX1()] = GetPixelStencil(x, y);
		}
		row += w;
	}
	return true;
}

bool GetCurrentTexture(GPUDebugBuffer &buffer)
{
	int w = gstate.getTextureWidth(0);
	int h = gstate.getTextureHeight(0);
	buffer.Allocate(w, h, GE_FORMAT_8888, false);

	GETextureFormat texfmt = gstate.getTextureFormat();
	u32 texaddr = gstate.getTextureAddress(0);
	int texbufwidthbits = GetTextureBufw(0, texaddr, texfmt) * 8;
	u8 *texptr = Memory::GetPointer(texaddr);

	u32 *row = (u32 *)buffer.GetData();
	for (int y = 0; y < h; ++y) {
		for (int x = 0; x < w; ++x) {
			row[x] = SampleNearest(0, x, y, texptr, texbufwidthbits);
		}
		row += w;
	}
	return true;
}

} // namespace