353 lines
11 KiB
C++
353 lines
11 KiB
C++
/*
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Copyright 2016-2017 StapleButter
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This file is part of melonDS.
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melonDS is free software: you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation, either version 3 of the License, or (at your option)
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any later version.
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melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with melonDS. If not, see http://www.gnu.org/licenses/.
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*/
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#include <stdio.h>
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#include <string.h>
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#include "NDS.h"
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#include "GPU3D.h"
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namespace GPU3D
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{
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namespace SoftRenderer
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{
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u8 ColorBuffer[256*192 * 4];
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u32 DepthBuffer[256*192];
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bool Init()
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{
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return true;
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}
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void DeInit()
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{
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//
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}
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void Reset()
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{
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memset(ColorBuffer, 0, 256*192 * 4);
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memset(DepthBuffer, 0, 256*192 * 4);
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}
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void RenderPixel(u32 attr, s32 x, s32 y, s32 z, u8 vr, u8 vg, u8 vb)
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{
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u32* depth = &DepthBuffer[(256*y) + x];
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bool passdepth = false;
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if (attr & (1<<14))
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{
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s32 diff = *depth - z;
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if ((u32)(diff + 0x200) <= 0x400)
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passdepth = true;
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}
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else
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if (z < *depth)
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passdepth = true;
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if (!passdepth) return;
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u8* pixel = &ColorBuffer[((256*y) + x) * 4];
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pixel[0] = vr;
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pixel[1] = vg;
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pixel[2] = vb;
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pixel[3] = 31; // TODO: alpha
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// TODO: optional update for translucent pixels
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*depth = z;
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}
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void RenderPolygon(Polygon* polygon)
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{
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int nverts = polygon->NumVertices;
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int vtop = 0, vbot = 0;
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s32 ytop = 191, ybot = 0;
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// process the vertices, transform to screen coordinates
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// find the topmost and bottommost vertices of the polygon
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for (int i = 0; i < nverts; i++)
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{
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Vertex* vtx = polygon->Vertices[i];
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if (!vtx->ViewportTransformDone)
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{
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s32 posX, posY, posZ, posW;
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s32 w = vtx->Position[3];
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if (w == 0)
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{
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posX = 0;
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posY = 0;
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posZ = 0;
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posW = 0x1000;
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}
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else
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{
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posX = ((s64)vtx->Position[0] << 12) / w;
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posY = ((s64)vtx->Position[1] << 12) / w;
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// TODO: W-buffering
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posZ = (((s64)vtx->Position[2] * 0x800000) / w) + 0x7FFCFF;
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posW = w;
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}
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s32 scrX = (((posX + 0x1000) * Viewport[2]) >> 13) + Viewport[0];
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s32 scrY = (((posY + 0x1000) * Viewport[3]) >> 13) + Viewport[1];
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if (scrX < 0) scrX = 0;
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else if (scrX > 255) scrX = 255;
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if (scrY < 0) scrY = 0;
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else if (scrY > 191) scrY = 191;
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if (posZ < 0) posZ = 0;
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else if (posZ > 0xFFFFFF) posZ = 0xFFFFFF;
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vtx->FinalPosition[0] = scrX;
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vtx->FinalPosition[1] = 191 - scrY;
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vtx->FinalPosition[2] = posZ;
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vtx->FinalPosition[3] = posW;
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vtx->FinalColor[0] = vtx->Color[0] ? ((vtx->Color[0] << 4) + 0xF) : 0;
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vtx->FinalColor[1] = vtx->Color[1] ? ((vtx->Color[1] << 4) + 0xF) : 0;
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vtx->FinalColor[2] = vtx->Color[2] ? ((vtx->Color[2] << 4) + 0xF) : 0;
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vtx->ViewportTransformDone = true;
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}
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if (vtx->FinalPosition[1] < ytop)
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{
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ytop = vtx->FinalPosition[1];
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vtop = i;
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}
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if (vtx->FinalPosition[1] > ybot)
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{
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ybot = vtx->FinalPosition[1];
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vbot = i;
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}
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}
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// draw, line per line
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int lcur = vtop, rcur = vtop;
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int lnext, rnext;
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if (polygon->FacingView)
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{
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lnext = lcur + 1;
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if (lnext >= nverts) lnext = 0;
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rnext = rcur - 1;
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if (rnext < 0) rnext = nverts - 1;
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}
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else
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{
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lnext = lcur - 1;
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if (lnext < 0) lnext = nverts - 1;
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rnext = rcur + 1;
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if (rnext >= nverts) rnext = 0;
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}
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for (s32 y = ytop; y <= ybot; y++)
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{
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if (y < ybot)
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{
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while (y == polygon->Vertices[lnext]->FinalPosition[1])
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{
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lcur = lnext;
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if (polygon->FacingView)
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{
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lnext = lcur + 1;
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if (lnext >= nverts) lnext = 0;
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}
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else
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{
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lnext = lcur - 1;
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if (lnext < 0) lnext = nverts - 1;
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}
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if (lcur == vbot) break;
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}
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while (y == polygon->Vertices[rnext]->FinalPosition[1])
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{
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rcur = rnext;
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if (polygon->FacingView)
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{
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rnext = rcur - 1;
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if (rnext < 0) rnext = nverts - 1;
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}
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else
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{
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rnext = rcur + 1;
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if (rnext >= nverts) rnext = 0;
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}
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if (rcur == vbot) break;
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}
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}
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Vertex* vlcur = polygon->Vertices[lcur];
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Vertex* vlnext = polygon->Vertices[lnext];
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Vertex* vrcur = polygon->Vertices[rcur];
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Vertex* vrnext = polygon->Vertices[rnext];
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s32 lfactor, rfactor;
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if (vlnext->FinalPosition[1] == vlcur->FinalPosition[1])
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lfactor = 0;
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else
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lfactor = ((y - vlcur->FinalPosition[1]) << 12) / (vlnext->FinalPosition[1] - vlcur->FinalPosition[1]);
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if (vrnext->FinalPosition[1] == vrcur->FinalPosition[1])
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rfactor = 0;
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else
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rfactor = ((y - vrcur->FinalPosition[1]) << 12) / (vrnext->FinalPosition[1] - vrcur->FinalPosition[1]);
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s32 xl = vlcur->FinalPosition[0] + (((vlnext->FinalPosition[0] - vlcur->FinalPosition[0]) * lfactor) >> 12);
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s32 xr = vrcur->FinalPosition[0] + (((vrnext->FinalPosition[0] - vrcur->FinalPosition[0]) * rfactor) >> 12);
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if (xl<0 || xr>255)
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{
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printf("!! BAD X %d %d\n", xl, xr);
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continue; // hax
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}
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s32 zl = vlcur->FinalPosition[2] + (((s64)(vlnext->FinalPosition[2] -vlcur->FinalPosition[2]) * lfactor) >> 12);
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s32 zr = vrcur->FinalPosition[2] + (((s64)(vrnext->FinalPosition[2] - vrcur->FinalPosition[2]) * rfactor) >> 12);
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s32 wl = vlcur->FinalPosition[3] + (((s64)(vlnext->FinalPosition[3] - vlcur->FinalPosition[3]) * lfactor) >> 12);
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s32 wr = vrcur->FinalPosition[3] + (((s64)(vrnext->FinalPosition[3] - vrcur->FinalPosition[3]) * rfactor) >> 12);
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s64 perspfactorl1 = ((s64)(0x1000 - lfactor) << 12) / vlcur->FinalPosition[3];
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s64 perspfactorl2 = ((s64)lfactor << 12) / vlnext->FinalPosition[3];
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s64 perspfactorr1 = ((s64)(0x1000 - rfactor) << 12) / vrcur->FinalPosition[3];
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s64 perspfactorr2 = ((s64)rfactor << 12) / vrnext->FinalPosition[3];
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if (perspfactorl1 + perspfactorl2 == 0)
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{
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perspfactorl1 = 0x1000;
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perspfactorl2 = 0;
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}
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if (perspfactorr1 + perspfactorr2 == 0)
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{
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perspfactorr1 = 0x1000;
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perspfactorr2 = 0;
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}
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s32 rl = ((perspfactorl1 * vlcur->FinalColor[0]) + (perspfactorl2 * vlnext->FinalColor[0])) / (perspfactorl1 + perspfactorl2);
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s32 gl = ((perspfactorl1 * vlcur->FinalColor[1]) + (perspfactorl2 * vlnext->FinalColor[1])) / (perspfactorl1 + perspfactorl2);
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s32 bl = ((perspfactorl1 * vlcur->FinalColor[2]) + (perspfactorl2 * vlnext->FinalColor[2])) / (perspfactorl1 + perspfactorl2);
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s32 rr = ((perspfactorr1 * vrcur->FinalColor[0]) + (perspfactorr2 * vrnext->FinalColor[0])) / (perspfactorr1 + perspfactorr2);
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s32 gr = ((perspfactorr1 * vrcur->FinalColor[1]) + (perspfactorr2 * vrnext->FinalColor[1])) / (perspfactorr1 + perspfactorr2);
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s32 br = ((perspfactorr1 * vrcur->FinalColor[2]) + (perspfactorr2 * vrnext->FinalColor[2])) / (perspfactorr1 + perspfactorr2);
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s32 xdiv;
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if (xr == xl)
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xdiv = 0;
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else
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xdiv = 0x1000 / (xr - xl);
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for (s32 x = xl; x <= xr; x++)
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{
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s32 xfactor = (x - xl) * xdiv;
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s32 z = zl + (((s64)(zr - zl) * xfactor) >> 12);
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//z = wl + (((s64)(wr - wl) * xfactor) >> 12);
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//z -= 0x1FF;
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//if (z < 0) z = 0;
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s32 perspfactor1 = ((0x1000 - xfactor) << 12) / wl;
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s32 perspfactor2 = (xfactor << 12) / wr;
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if (perspfactor1 + perspfactor2 == 0)
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{
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perspfactor1 = 0x1000;
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perspfactor2 = 0;
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}
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// possible optimization: only do color interpolation if the depth test passes
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u32 vr = ((perspfactor1 * rl) + (perspfactor2 * rr)) / (perspfactor1 + perspfactor2);
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u32 vg = ((perspfactor1 * gl) + (perspfactor2 * gr)) / (perspfactor1 + perspfactor2);
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u32 vb = ((perspfactor1 * bl) + (perspfactor2 * br)) / (perspfactor1 + perspfactor2);
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RenderPixel(polygon->Attr, x, y, z, vr>>3, vg>>3, vb>>3);
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// Z debug
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/*u8 zerp = (w * 63) / 0xFFFFFF;
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pixel[0] = zerp;
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pixel[1] = zerp;
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pixel[2] = zerp;*/
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}
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}
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// DEBUG CODE
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/*for (int i = 0; i < nverts; i++)
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{
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s32 x = scrcoords[i][0];
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s32 y = scrcoords[i][1];
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u8* pixel = &ColorBuffer[((256*y) + x) * 4];
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pixel[0] = 63;
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pixel[1] = 63;
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pixel[2] = 63;
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pixel[3] = 31;
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}*/
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}
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void RenderFrame(Vertex* vertices, Polygon* polygons, int npolys)
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{
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// TODO: render translucent polygons last
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// TODO proper clear color/depth support!
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for (int i = 0; i < 256*192; i++)
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{
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((u32*)ColorBuffer)[i] = 0x00000000;
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DepthBuffer[i] = 0xFFFFFF;
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}
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for (int i = 0; i < npolys; i++)
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{
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/*printf("polygon %d: %d %d %d\n", i, polygons[i].Vertices[0]->Color[0], polygons[i].Vertices[0]->Color[1], polygons[i].Vertices[0]->Color[2]);
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for (int j = 0; j < polygons[i].NumVertices; j++)
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printf(" %d: %f %f %f\n",
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j,
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polygons[i].Vertices[j]->Position[0]/4096.0f,
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polygons[i].Vertices[j]->Position[1]/4096.0f,
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polygons[i].Vertices[j]->Position[2]/4096.0f);
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*/
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//printf("polygon %d\n", i);
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//if (!polygons[i].Vertices[0]->Clipped) continue;
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//printf("polygon %d\n", i);
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RenderPolygon(&polygons[i]);
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}
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}
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u8* GetLine(int line)
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{
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return &ColorBuffer[line * 256 * 4];
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}
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}
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}
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