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();
}
}
}
}
