package uk.org.floop.epq3d; import java.awt.*; public class Triangle{ public PointComp point1; public PointComp point2; public PointComp point3; public Matrix[] perspectiveMappingMatrix; public boolean[] edgeList; //edge 1-2 , 2-3, 3-1 private Line2d LineLong; private Line2d LineA; private Line2d LineB; public Texture texture; // initialisation variables private boolean is_initialised = false; private Point2D min; private Point2D max; private Point2D startPoint; private double xGradient; private double yGradient; private final Point2D result2 = new Point2D(0,0); public void invalidate() { is_initialised = false; } public Triangle(PointComp _pA, PointComp _pB, PointComp _pC, boolean[] _edgeList, Texture _texture, Matrix[] mapMatrix){ point1 = _pA; point2 = _pB; point3 = _pC; edgeList = _edgeList; texture = _texture; perspectiveMappingMatrix = mapMatrix; } // returns int for debug public int draw(drawData drawData, double ang){ // long lastMillis; if (!is_initialised){ if(initialise(drawData)){ int[] point1; int[] point2; char currentLine = 'A'; lastMillis = System.currentTimeMillis(); point1 = LineLong.nextPix(); point2 = LineA.nextPix(); for(int x = min.x+1; x <= max.x; x += 1) { while(x-1 == point1[0]) { if((LineLong.isDrawn || drawData.drawLines) && // draw line pixels if needed, and on screen point1[0] > 0 && point1[1] > 0 && point1[0] < drawData.scrX && point1[1] < drawData.scrY){ drawData.drawImg[point1[0]][point1[1]] = Color.HSBtoRGB(0, 1, 1); } try { point1 = LineLong.nextPix(); } catch (Exception e){ throw new RuntimeException("accessed too many line pixels"); } } while(x-1 == point2[0]) { if (currentLine == 'A') { try{ if((LineA.isDrawn || drawData.drawLines) && // draw line pixels if needed, and on screen point2[0] > 0 && point2[1] > 0 && point2[0] < drawData.scrX && point2[1] < drawData.scrY){ drawData.drawImg[point2[0]][point2[1]] = Color.HSBtoRGB(0, 1, 1); } point2 = LineA.nextPix(); } catch (RuntimeException e){ currentLine = 'B'; } } else { if((LineB.isDrawn || drawData.drawLines) && // draw line pixels if needed, and on screen point2[0] > 0 && point2[1] > 0 && point2[0] < drawData.scrX && point2[1] < drawData.scrY){ drawData.drawImg[point2[0]][point2[1]] = Color.HSBtoRGB(0, 1, 1); } point2 = LineB.nextPix(); } } // cancel drawing if the x value of the triangle is out of bounds if (x >= drawData.scrX) {break;} if (x > 0) { if (point1[1] < point2[1]) { double z1 = LineLong.getZVal(x); double z2; if(currentLine=='A'){ z2=LineA.getZVal(x); } else{ z2=LineB.getZVal(x); } double gradient = -(z2 - z1) / (point2[1]-point1[1]); for (int y = Math.max(point1[1], 0); y <= Math.min(point2[1], drawData.scrY - 1); y += 1) { // function only exists so I don't have to copy paste code everywhere. drawPix(drawData, x, y, ang); } } else { double z2 = LineLong.getZVal(x); double z1; if(currentLine=='A'){ z1=LineA.getZVal(x); } else{ z1=LineB.getZVal(x); } double gradient = -(z2 - z1) / (point1[1]-point2[1]); for (int y = Math.max(point2[1], 0); y <= Math.min(point1[1], drawData.scrY - 1); y += 1) { drawPix(drawData, x, y, ang); } } } } lastMillis = (System.currentTimeMillis() - lastMillis); return (int)lastMillis; } } return 0; } public boolean initialise(drawData drawData){ if (point1 == null || point2 == null || point3 == null){ throw new NullPointerException(); } min = new Point2D( Math.min(point1.getProjectedPoint().x, Math.min(point2.getProjectedPoint().x, point3.getProjectedPoint().x)), Math.min(point1.getProjectedPoint().y, Math.min(point2.getProjectedPoint().y, point3.getProjectedPoint().y))); max = new Point2D( Math.max(point1.getProjectedPoint().x, Math.max(point2.getProjectedPoint().x, point3.getProjectedPoint().x)), Math.max(point1.getProjectedPoint().y, Math.max(point2.getProjectedPoint().y, point3.getProjectedPoint().y))); if(max.x < 0 || min.x > drawData.scrX || max.y < 0 || min.y > drawData.scrY){ return false; } // woo horrible IFs mess. // we need to figure out which points touch the edges in order to find which line is the 'full length' edge, // and then assign line A and line B in order if (point1.getProjectedPoint().x == min.x) { if (point2.getProjectedPoint().x == max.x){ LineLong = new Line2d(point1, point2, edgeList[0]); LineA = new Line2d(point1, point3, edgeList[2]); LineB = new Line2d(point3, point2, edgeList[1]); } else { LineLong = new Line2d(point1, point3, edgeList[2]); LineA = new Line2d(point1, point2, edgeList[0]); LineB = new Line2d(point2, point3, edgeList[1]); } } else if (point2.getProjectedPoint().x == min.x) { if (point1.getProjectedPoint().x == max.x) { LineLong = new Line2d(point2, point1, edgeList[0]); LineA = new Line2d(point2, point3, edgeList[1]); LineB = new Line2d(point3, point1, edgeList[2]); } else { LineLong = new Line2d(point2, point3, edgeList[1]); LineA = new Line2d(point2, point1, edgeList[0]); LineB = new Line2d(point1, point3, edgeList[2]); } } else if (point3.getProjectedPoint().x == min.x){ if (point1.getProjectedPoint().x == max.x) { LineLong = new Line2d(point3, point1, edgeList[2]); LineA = new Line2d(point3, point2, edgeList[1]); LineB = new Line2d(point2, point1, edgeList[0]); } else { LineLong = new Line2d(point3, point2, edgeList[2]); LineA = new Line2d(point3, point1, edgeList[1]); LineB = new Line2d(point1, point2, edgeList[0]); } } // find z calculation constants // they are always relative to lineLong point1. This is an arbitrary decision but it must be consistent startPoint = LineLong.point1.getProjectedPoint(); // find two vectors in screen coordinates from the point Vector3D vec1 = new Vector3D( LineLong.point2.getProjectedPoint().x - startPoint.x, LineLong.point2.getProjectedPoint().y - startPoint.y, 1/LineLong.point2.getRotatedPoint().z - 1/startPoint.z ); // in theory, projected point and rotated point Z values are the same. However, at some point i'd like to remove z values from 2d points Vector3D vec2 = new Vector3D( LineA.point2.getProjectedPoint().x - startPoint.x, LineA.point2.getProjectedPoint().y - startPoint.y, 1/LineA.point2.getRotatedPoint().z - 1/startPoint.z ); // calculate the cross product of these two vectors in order to obtain a normal vector Vector3D cross = vec1.cross(vec2); // find xGradient and yGradient for the triangle, in terms of z. We take the negative reciprocal of these gradients, because of the normal vector. xGradient = -cross.x / cross.z; yGradient = -cross.y / cross.z; if(!Double.isFinite(xGradient)){ xGradient = 0; } if(!Double.isFinite(yGradient)){ yGradient = 0; } // double testZ2 = LineLong.point2.getProjectedPoint().z; // double testZ = refPoint.getProjectedPoint().z + // xGradient * (LineLong.point2.getProjectedPoint().x-refPoint.getProjectedPoint().x) + // yGradient * (LineLong.point2.getProjectedPoint().y-refPoint.getProjectedPoint().y); double testZ2 = LineA.point2.getProjectedPoint().z; double testZ = 1/(1/startPoint.z + xGradient * (LineA.point2.getProjectedPoint().x-startPoint.x) + yGradient * (LineA.point2.getProjectedPoint().y-startPoint.y)); //System.out.println(testZ - testZ2); // assign points to lines is_initialised = true; return true; } private void drawPix(drawData drawData, int x, int y, double ang){ // a value of 0 represents a value which is on the camera, at z=0. // not the best mapping but it's probably good enough double zVal = 1/((1/startPoint.z + (x - startPoint.x)*xGradient + (y - startPoint.y)*yGradient)); int newZ = (int)(2147483647d/(zVal + 1)); // if (newZ == 2147483647){ // System.out.println((1/startPoint.z + // (x - startPoint.x)*xGradient + // (y - startPoint.y)*yGradient)); // } // if the new Z value is greater than the existing Z value on the buffer, the new pixel is calculated and drawn if(drawData.zBuf[x][y] == 0 || newZ > drawData.zBuf[x][y]){ //newZ > zBuf.getRGB(x, y) || drawData.zBuf[x][y] = newZ; // project result Color pixColor; if(texture.isSolid()){ pixColor = texture.getColor(ang); } else { throw new RuntimeException("Textures are not supported"); } if(drawData.drawZBuffer){ drawData.drawImg[x][y] = Color.getHSBColor((float)newZ/2147483648f + 0.5f, 1, 1).getRGB(); } else{ drawData.drawImg[x][y] = pixColor.getRGB(); } } } }