Implementation of: - Matrix multiplication - 3D projection + a fix for points behind the camera

Browse code Implementation of: - Matrix multiplication - 3D projection + a fix for points behind the camera master V1
1 parent e32b437 commit f9dc322893cb98cf7afb0681d3a64265e489725a cory authored on 6 Nov 2022

+public class Matrix {
+    protected int x;
+    protected int y;
+    private double[][] items;
+    public Matrix(int _x, int _y){
+        x = _x; y= _y;
+        items = new double[y][x];
+    }
+    public double item(int _x, int _y){
+        return items[_y][_x];
+    }
+    public void setItem(int _x, int _y, double val){
+        items[_y][_x] = val;
+    }
+    public double[][] getItems() {
+        return items;
+    }
+    public void setItems(double[][] newItems){
+        items = newItems;
+    }
+    public Matrix multiply(Matrix mult) {
+        Matrix result = new Matrix(mult.x, this.y);
+        double newItem;
+        if(x==mult.y){
+            for(int rx = 0; rx< result.x; rx+=1){
+                for(int ry = 0; ry< result.y; ry+=1){
+                    newItem = 0;
+                    for(int i = 0; i<x; i+=1){
+                        newItem += this.item(i, ry)*mult.item(rx, i);
+                    }
+                    result.setItem(rx, ry, newItem);
+            }}
+        } else {
+            throw new RuntimeException("wrong dimensions");
+        }
+        return result;
+    }
+    public Point3D multiplyPoint3(Point3D point) {
+        double px;double py; double pz;
+        if(x==3){
+            px = point.x * item(0,0) + point.y*item(1,0) + point.z*item(2,0);
+            py = point.x * item(0,1) + point.y*item(1,1) + point.z*item(2,1);
+            pz = point.x * item(0,2) + point.y*item(1,2) + point.z*item(2,2);
+        } else if(x == 4){
+            px = point.x * item(0,0) + point.y*item(1,0) + point.z*item(2,0) + item(3,0);
+            py = point.x * item(0,1) + point.y*item(1,1) + point.z*item(2,1) + item(3,1);
+            pz = point.x * item(0,2) + point.y*item(1,2) + point.z*item(2,2) + item(3,2);
+        } else {throw new RuntimeException("wrong-dimensions");}
+        return new Point3D(px, py, pz);
+    }
+    public Point2D multiplyPoint2(Point3D point) throws Exception {
+        double px;double py;
+        if(x==2){
+            px = point.x * item(0,0) + point.y*item(0,1);
+            py = point.x * item(1,0) + point.y*item(1,1);
+        } else if(x == 3){
+            px = point.x * item(0,0) + point.y*item(0,1) + item(0,2);
+            py = point.x * item(1,0) + point.y*item(1,1) + item(1,2);
+        } else {throw new Exception("wrong-dimensions");}
+        return new Point2D(px, py);
+    }
+}