forked from dolphin-emu/dolphin
461 lines
17 KiB
C++
461 lines
17 KiB
C++
// Copyright 2009 Dolphin Emulator Project
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// Licensed under GPLv2+
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// Refer to the license.txt file included.
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/*
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Portions of this file are based off work by Markus Trenkwalder.
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Copyright (c) 2007, 2008 Markus Trenkwalder
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright notice,
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this list of conditions and the following disclaimer in the documentation
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and/or other materials provided with the distribution.
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* Neither the name of the library's copyright owner nor the names of its
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contributors may be used to endorse or promote products derived from this
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software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "VideoBackends/Software/Clipper.h"
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#include "Common/Assert.h"
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#include "VideoBackends/Software/NativeVertexFormat.h"
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#include "VideoBackends/Software/Rasterizer.h"
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#include "VideoCommon/BPMemory.h"
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#include "VideoCommon/Statistics.h"
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#include "VideoCommon/XFMemory.h"
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namespace Clipper
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{
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enum
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{
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NUM_CLIPPED_VERTICES = 33,
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NUM_INDICES = NUM_CLIPPED_VERTICES + 3
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};
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static OutputVertexData ClippedVertices[NUM_CLIPPED_VERTICES];
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static OutputVertexData* Vertices[NUM_INDICES];
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void Init()
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{
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for (int i = 0; i < NUM_CLIPPED_VERTICES; ++i)
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Vertices[i + 3] = &ClippedVertices[i];
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}
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enum
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{
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SKIP_FLAG = -1,
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CLIP_POS_X_BIT = 0x01,
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CLIP_NEG_X_BIT = 0x02,
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CLIP_POS_Y_BIT = 0x04,
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CLIP_NEG_Y_BIT = 0x08,
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CLIP_POS_Z_BIT = 0x10,
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CLIP_NEG_Z_BIT = 0x20
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};
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static inline int CalcClipMask(const OutputVertexData* v)
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{
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int cmask = 0;
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Vec4 pos = v->projectedPosition;
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if (pos.w - pos.x < 0)
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cmask |= CLIP_POS_X_BIT;
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if (pos.x + pos.w < 0)
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cmask |= CLIP_NEG_X_BIT;
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if (pos.w - pos.y < 0)
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cmask |= CLIP_POS_Y_BIT;
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if (pos.y + pos.w < 0)
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cmask |= CLIP_NEG_Y_BIT;
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if (pos.w * pos.z > 0)
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cmask |= CLIP_POS_Z_BIT;
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if (pos.z + pos.w < 0)
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cmask |= CLIP_NEG_Z_BIT;
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return cmask;
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}
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static inline void AddInterpolatedVertex(float t, int out, int in, int* numVertices)
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{
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Vertices[(*numVertices)++]->Lerp(t, Vertices[out], Vertices[in]);
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}
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#define DIFFERENT_SIGNS(x, y) ((x <= 0 && y > 0) || (x > 0 && y <= 0))
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#define CLIP_DOTPROD(I, A, B, C, D) \
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(Vertices[I]->projectedPosition.x * A + Vertices[I]->projectedPosition.y * B + \
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Vertices[I]->projectedPosition.z * C + Vertices[I]->projectedPosition.w * D)
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#define POLY_CLIP(PLANE_BIT, A, B, C, D) \
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{ \
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if (mask & PLANE_BIT) \
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{ \
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int idxPrev = inlist[0]; \
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float dpPrev = CLIP_DOTPROD(idxPrev, A, B, C, D); \
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int outcount = 0; \
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\
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inlist[n] = inlist[0]; \
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for (int j = 1; j <= n; j++) \
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{ \
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int idx = inlist[j]; \
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float dp = CLIP_DOTPROD(idx, A, B, C, D); \
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if (dpPrev >= 0) \
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{ \
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outlist[outcount++] = idxPrev; \
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} \
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\
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if (DIFFERENT_SIGNS(dp, dpPrev)) \
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{ \
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if (dp < 0) \
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{ \
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float t = dp / (dp - dpPrev); \
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AddInterpolatedVertex(t, idx, idxPrev, &numVertices); \
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} \
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else \
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{ \
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float t = dpPrev / (dpPrev - dp); \
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AddInterpolatedVertex(t, idxPrev, idx, &numVertices); \
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} \
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outlist[outcount++] = numVertices - 1; \
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} \
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\
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idxPrev = idx; \
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dpPrev = dp; \
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} \
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\
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if (outcount < 3) \
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continue; \
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\
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{ \
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int* tmp = inlist; \
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inlist = outlist; \
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outlist = tmp; \
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n = outcount; \
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} \
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} \
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}
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#define LINE_CLIP(PLANE_BIT, A, B, C, D) \
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{ \
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if (mask & PLANE_BIT) \
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{ \
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const float dp0 = CLIP_DOTPROD(0, A, B, C, D); \
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const float dp1 = CLIP_DOTPROD(1, A, B, C, D); \
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const bool neg_dp0 = dp0 < 0; \
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const bool neg_dp1 = dp1 < 0; \
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\
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if (neg_dp0 && neg_dp1) \
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return; \
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\
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if (neg_dp1) \
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{ \
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float t = dp1 / (dp1 - dp0); \
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if (t > t1) \
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t1 = t; \
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} \
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else if (neg_dp0) \
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{ \
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float t = dp0 / (dp0 - dp1); \
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if (t > t0) \
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t0 = t; \
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} \
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} \
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}
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static void ClipTriangle(int* indices, int* numIndices)
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{
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int mask = 0;
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mask |= CalcClipMask(Vertices[0]);
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mask |= CalcClipMask(Vertices[1]);
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mask |= CalcClipMask(Vertices[2]);
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if (mask != 0)
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{
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for (int i = 0; i < 3; i += 3)
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{
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int vlist[2][2 * 6 + 1];
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int *inlist = vlist[0], *outlist = vlist[1];
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int n = 3;
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int numVertices = 3;
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inlist[0] = 0;
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inlist[1] = 1;
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inlist[2] = 2;
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// mark this triangle as unused in case it should be completely
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// clipped
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indices[0] = SKIP_FLAG;
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indices[1] = SKIP_FLAG;
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indices[2] = SKIP_FLAG;
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POLY_CLIP(CLIP_POS_X_BIT, -1, 0, 0, 1);
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POLY_CLIP(CLIP_NEG_X_BIT, 1, 0, 0, 1);
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POLY_CLIP(CLIP_POS_Y_BIT, 0, -1, 0, 1);
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POLY_CLIP(CLIP_NEG_Y_BIT, 0, 1, 0, 1);
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POLY_CLIP(CLIP_POS_Z_BIT, 0, 0, 0, 1);
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POLY_CLIP(CLIP_NEG_Z_BIT, 0, 0, 1, 1);
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INCSTAT(stats.thisFrame.numTrianglesClipped);
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// transform the poly in inlist into triangles
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indices[0] = inlist[0];
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indices[1] = inlist[1];
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indices[2] = inlist[2];
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for (int j = 3; j < n; ++j)
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{
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indices[(*numIndices)++] = inlist[0];
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indices[(*numIndices)++] = inlist[j - 1];
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indices[(*numIndices)++] = inlist[j];
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}
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}
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}
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}
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static void ClipLine(int* indices)
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{
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int mask = 0;
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int clip_mask[2] = {0, 0};
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for (int i = 0; i < 2; ++i)
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{
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clip_mask[i] = CalcClipMask(Vertices[i]);
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mask |= clip_mask[i];
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}
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if (mask == 0)
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return;
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float t0 = 0;
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float t1 = 0;
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// Mark unused in case of early termination
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// of the macros below. (When fully clipped)
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indices[0] = SKIP_FLAG;
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indices[1] = SKIP_FLAG;
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LINE_CLIP(CLIP_POS_X_BIT, -1, 0, 0, 1);
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LINE_CLIP(CLIP_NEG_X_BIT, 1, 0, 0, 1);
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LINE_CLIP(CLIP_POS_Y_BIT, 0, -1, 0, 1);
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LINE_CLIP(CLIP_NEG_Y_BIT, 0, 1, 0, 1);
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LINE_CLIP(CLIP_POS_Z_BIT, 0, 0, -1, 1);
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LINE_CLIP(CLIP_NEG_Z_BIT, 0, 0, 1, 1);
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// Restore the old values as this line
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// was not fully clipped.
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indices[0] = 0;
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indices[1] = 1;
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int numVertices = 2;
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if (clip_mask[0])
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{
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indices[0] = numVertices;
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AddInterpolatedVertex(t0, 0, 1, &numVertices);
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}
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if (clip_mask[1])
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{
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indices[1] = numVertices;
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AddInterpolatedVertex(t1, 1, 0, &numVertices);
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}
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}
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void ProcessTriangle(OutputVertexData* v0, OutputVertexData* v1, OutputVertexData* v2)
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{
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INCSTAT(stats.thisFrame.numTrianglesIn)
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bool backface;
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if (!CullTest(v0, v1, v2, backface))
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return;
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int indices[NUM_INDICES] = {0, 1, 2, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG,
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SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG,
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SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG, SKIP_FLAG,
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SKIP_FLAG, SKIP_FLAG, SKIP_FLAG};
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int numIndices = 3;
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if (backface)
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{
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Vertices[0] = v0;
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Vertices[1] = v2;
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Vertices[2] = v1;
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}
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else
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{
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Vertices[0] = v0;
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Vertices[1] = v1;
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Vertices[2] = v2;
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}
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ClipTriangle(indices, &numIndices);
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for (int i = 0; i + 3 <= numIndices; i += 3)
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{
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_assert_(i < NUM_INDICES);
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if (indices[i] != SKIP_FLAG)
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{
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PerspectiveDivide(Vertices[indices[i]]);
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PerspectiveDivide(Vertices[indices[i + 1]]);
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PerspectiveDivide(Vertices[indices[i + 2]]);
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Rasterizer::DrawTriangleFrontFace(Vertices[indices[i]], Vertices[indices[i + 1]],
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Vertices[indices[i + 2]]);
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}
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}
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}
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static void CopyVertex(OutputVertexData* dst, const OutputVertexData* src, float dx, float dy,
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unsigned int sOffset)
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{
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dst->screenPosition.x = src->screenPosition.x + dx;
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dst->screenPosition.y = src->screenPosition.y + dy;
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dst->screenPosition.z = src->screenPosition.z;
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for (int i = 0; i < 3; ++i)
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dst->normal[i] = src->normal[i];
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for (int i = 0; i < 4; ++i)
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dst->color[0][i] = src->color[0][i];
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// todo - s offset
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for (int i = 0; i < 8; ++i)
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dst->texCoords[i] = src->texCoords[i];
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}
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void ProcessLine(OutputVertexData* lineV0, OutputVertexData* lineV1)
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{
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int indices[4] = {0, 1, SKIP_FLAG, SKIP_FLAG};
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Vertices[0] = lineV0;
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Vertices[1] = lineV1;
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// point to a valid vertex to store to when clipping
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Vertices[2] = &ClippedVertices[17];
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ClipLine(indices);
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if (indices[0] != SKIP_FLAG)
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{
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OutputVertexData* v0 = Vertices[indices[0]];
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OutputVertexData* v1 = Vertices[indices[1]];
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PerspectiveDivide(v0);
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PerspectiveDivide(v1);
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float dx = v1->screenPosition.x - v0->screenPosition.x;
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float dy = v1->screenPosition.y - v0->screenPosition.y;
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float screenDx = 0;
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float screenDy = 0;
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if (fabsf(dx) > fabsf(dy))
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{
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if (dx > 0)
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screenDy = bpmem.lineptwidth.linesize / -12.0f;
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else
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screenDy = bpmem.lineptwidth.linesize / 12.0f;
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}
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else
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{
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if (dy > 0)
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screenDx = bpmem.lineptwidth.linesize / 12.0f;
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else
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screenDx = bpmem.lineptwidth.linesize / -12.0f;
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}
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OutputVertexData triangle[3];
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CopyVertex(&triangle[0], v0, screenDx, screenDy, 0);
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CopyVertex(&triangle[1], v1, screenDx, screenDy, 0);
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CopyVertex(&triangle[2], v1, -screenDx, -screenDy, bpmem.lineptwidth.lineoff);
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// ccw winding
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Rasterizer::DrawTriangleFrontFace(&triangle[2], &triangle[1], &triangle[0]);
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CopyVertex(&triangle[1], v0, -screenDx, -screenDy, bpmem.lineptwidth.lineoff);
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Rasterizer::DrawTriangleFrontFace(&triangle[0], &triangle[1], &triangle[2]);
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}
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}
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bool CullTest(const OutputVertexData* v0, const OutputVertexData* v1, const OutputVertexData* v2,
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bool& backface)
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{
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int mask = CalcClipMask(v0);
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mask &= CalcClipMask(v1);
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mask &= CalcClipMask(v2);
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if (mask)
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{
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INCSTAT(stats.thisFrame.numTrianglesRejected)
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return false;
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}
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float x0 = v0->projectedPosition.x;
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float x1 = v1->projectedPosition.x;
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float x2 = v2->projectedPosition.x;
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float y1 = v1->projectedPosition.y;
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float y0 = v0->projectedPosition.y;
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float y2 = v2->projectedPosition.y;
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float w0 = v0->projectedPosition.w;
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float w1 = v1->projectedPosition.w;
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float w2 = v2->projectedPosition.w;
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float normalZDir = (x0 * w2 - x2 * w0) * y1 + (x2 * y0 - x0 * y2) * w1 + (y2 * w0 - y0 * w2) * x1;
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backface = normalZDir <= 0.0f;
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if ((bpmem.genMode.cullmode & 1) && !backface) // cull frontfacing
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{
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INCSTAT(stats.thisFrame.numTrianglesCulled)
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return false;
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}
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if ((bpmem.genMode.cullmode & 2) && backface) // cull backfacing
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{
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INCSTAT(stats.thisFrame.numTrianglesCulled)
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return false;
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}
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return true;
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}
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void PerspectiveDivide(OutputVertexData* vertex)
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{
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Vec4& projected = vertex->projectedPosition;
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Vec3& screen = vertex->screenPosition;
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float wInverse = 1.0f / projected.w;
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screen.x = projected.x * wInverse * xfmem.viewport.wd + xfmem.viewport.xOrig - 342;
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screen.y = projected.y * wInverse * xfmem.viewport.ht + xfmem.viewport.yOrig - 342;
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screen.z = projected.z * wInverse * xfmem.viewport.zRange + xfmem.viewport.farZ;
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}
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}
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