rasterize: continue formulating new triangle engine into a form that will be easier to extend to quads
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zeromus
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cfc4dfe53d
commit
e7c46f12a0
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@ -23,7 +23,7 @@
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//nothing in this file should be assumed to be accurate
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const bool USE_HECKER = false;
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//#define USE_HECKER
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#include "rasterize.h"
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@ -170,10 +170,11 @@ static VERT* verts[3];
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INLINE static void SubmitVertex(int vert_index, VERT* rawvert)
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{
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//HACK - reverse winding
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if(USE_HECKER)
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#ifdef USE_HECKER
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verts[2-vert_index] = rawvert;
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else
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#else
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verts[vert_index] = rawvert;
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#endif
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}
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static Fragment screen[256*192];
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@ -781,89 +782,92 @@ void hecker_DrawScanLine( gradients_fx_fl const &Gradients,edge_fx_fl *pLeft, ed
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}
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}
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static void runscanline(gradients_fx_fl & gradients, edge_fx_fl *left, edge_fx_fl *right)
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{
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int Height = min(left->Height,right->Height);
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while(Height--) {
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hecker_DrawScanLine(gradients,left,right);
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left->Step(); right->Step();
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}
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}
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//http://chrishecker.com/Miscellaneous_Technical_Articles
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static void triangle_from_hecker()
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{
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int Top, Middle, Bottom, MiddleForCompare, BottomForCompare;
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fixed28_4 Y0 = verts[0]->y, Y1 = verts[1]->y, Y2 = verts[2]->y;
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VERT* v[3] = {verts[0],verts[1],verts[2]};
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// sort vertices in y
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if(Y0 < Y1) {
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if(Y2 < Y0) {
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Top = 2; Middle = 0; Bottom = 1;
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MiddleForCompare = 0; BottomForCompare = 1;
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} else {
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Top = 0;
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if(Y1 < Y2) {
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Middle = 1; Bottom = 2;
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MiddleForCompare = 1; BottomForCompare = 2;
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} else {
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Middle = 2; Bottom = 1;
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MiddleForCompare = 2; BottomForCompare = 1;
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}
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//rotate verts until vert0.y is minimum, and then vert0.x is minimum in case of ties
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//this will reduce the complexity of our logic
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while(v[0]->y > v[1]->y || v[0]->y > v[2]->y) {
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swap(v[0],v[1]);
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swap(v[1],v[2]);
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}
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while(v[0]->y == v[1]->y && v[0]->x > v[1]->x) {
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swap(v[0],v[1]);
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swap(v[1],v[2]);
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}
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//wants clockwise
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fixed28_4 Y0 = v[0]->y, Y1 = v[1]->y, Y2 = v[2]->y;
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gradients_fx_fl Gradients((const VERT**)v);
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if(Y0 == Y1)
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{
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//if the first two points have the same y-coord, then there is only one pair of edges
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edge_fx_fl edge1 = edge_fx_fl(Gradients,v,0,2);
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edge_fx_fl edge2 = edge_fx_fl(Gradients,v,1,2);
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runscanline(Gradients,&edge1,&edge2);
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}
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else if(Y1 == Y2)
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{
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//if the last two points have the same y-coord then there is only one pair of edges
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edge_fx_fl edge1 = edge_fx_fl(Gradients,v,0,2);
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edge_fx_fl edge2 = edge_fx_fl(Gradients,v,0,1);
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runscanline(Gradients,&edge1,&edge2);
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}
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else
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{
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//there are two pairs of edges
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if(Y1<Y2)
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{
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//a triangle like
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// 0
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// 1
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//2
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edge_fx_fl edge1 = edge_fx_fl(Gradients,v,0,2);
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edge_fx_fl edge2 = edge_fx_fl(Gradients,v,0,1);
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runscanline(Gradients,&edge1,&edge2);
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edge2 = edge_fx_fl(Gradients,v,1,2);
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runscanline(Gradients,&edge1,&edge2);
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}
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} else {
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if(Y2 < Y1) {
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Top = 2; Middle = 1; Bottom = 0;
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MiddleForCompare = 1; BottomForCompare = 0;
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} else {
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Top = 1;
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if(Y0 < Y2) {
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Middle = 0; Bottom = 2;
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MiddleForCompare = 3; BottomForCompare = 2;
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} else {
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Middle = 2; Bottom = 0;
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MiddleForCompare = 2; BottomForCompare = 3;
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}
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else
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{
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//a triangle like
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// 0
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//2
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// 1
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edge_fx_fl edge1 = edge_fx_fl(Gradients,v,0,2);
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edge_fx_fl edge2 = edge_fx_fl(Gradients,v,0,1);
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runscanline(Gradients,&edge1,&edge2);
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edge1 = edge_fx_fl(Gradients,v,2,1);
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runscanline(Gradients,&edge1,&edge2);
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}
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}
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gradients_fx_fl Gradients((const VERT**)verts);
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edge_fx_fl TopToBottom(Gradients,verts,Top,Bottom);
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edge_fx_fl TopToMiddle(Gradients,verts,Top,Middle);
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edge_fx_fl MiddleToBottom(Gradients,verts,Middle,Bottom);
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edge_fx_fl *pLeft, *pRight;
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int MiddleIsLeft;
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if(BottomForCompare > MiddleForCompare) {
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MiddleIsLeft = 0;
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pLeft = &TopToBottom; pRight = &TopToMiddle;
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} else {
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MiddleIsLeft = 1;
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pLeft = &TopToMiddle; pRight = &TopToBottom;
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}
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int Height = TopToMiddle.Height;
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while(Height--) {
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hecker_DrawScanLine(Gradients,pLeft,pRight);
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TopToMiddle.Step(); TopToBottom.Step();
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}
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Height = MiddleToBottom.Height;
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if(MiddleIsLeft) {
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pLeft = &MiddleToBottom; pRight = &TopToBottom;
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} else {
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pLeft = &TopToBottom; pRight = &MiddleToBottom;
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}
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while(Height--) {
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hecker_DrawScanLine(Gradients,pLeft,pRight);
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MiddleToBottom.Step(); TopToBottom.Step();
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}
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}
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//http://www.devmaster.net/forums/showthread.php?t=1884&page=1
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static void triangle_from_devmaster()
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{
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if(USE_HECKER)
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#ifdef USE_HECKER
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{
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triangle_from_hecker();
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return;
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}
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#endif
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// 28.4 fixed-point coordinates
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const int Y1 = iround(16.0f * verts[0]->coord[1]);
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@ -1381,10 +1385,11 @@ static void SoftRastRender()
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needInitTexture = false;
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}
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if(USE_HECKER)
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#ifdef USE_HECKER
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for(int i=0;i<type;i++)
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for(int j=0;j<2;j++)
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verts[i]->coord[j] = iround(16.0f * verts[i]->coord[j]);
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#endif
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//hmm... shader gets setup every time because it depends on sampler which may have just changed
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shader.setup(poly->polyAttr);
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