Starting of texture mapping to 3D coords

src/sig/ExtraData.java

@@ -0,0 +1,8 @@
+package sig;
+
+public class ExtraData {
+    public float t;
+    ExtraData(float t) {
+        this.t=t;
+    }
+}

src/sig/Panel.java

@@ -109,6 +109,9 @@ public class Panel extends JPanel implements Runnable {
             triTransformed.A = Matrix.MultiplyVector(matWorld,t.A);
             triTransformed.B = Matrix.MultiplyVector(matWorld,t.B);
             triTransformed.C = Matrix.MultiplyVector(matWorld,t.C);
+            triTransformed.T = t.T;
+            triTransformed.U = t.U;
+            triTransformed.V = t.V;
 
             Vector normal=new Vector(),line1=new Vector(),line2=new Vector();
             line1 = Vector.subtract(triTransformed.B,triTransformed.A);
@@ -130,6 +133,9 @@ public class Panel extends JPanel implements Runnable {
                 triViewed.B = Matrix.MultiplyVector(matView,triTransformed.B);
                 triViewed.C = Matrix.MultiplyVector(matView,triTransformed.C);
                 triViewed.setColor(new Color(dp,dp,dp));
+                triViewed.T = triTransformed.T;
+                triViewed.U = triTransformed.U;
+                triViewed.V = triTransformed.V;
 
                 int clippedTriangles = 0;
                 Triangle[] clipped = new Triangle[]{new Triangle(),new Triangle()};
@@ -143,6 +149,9 @@ public class Panel extends JPanel implements Runnable {
                     triProjected.B = Matrix.MultiplyVector(SigRenderer.matProj,clipped[i].B);
                     triProjected.C = Matrix.MultiplyVector(SigRenderer.matProj,clipped[i].C);
                     triProjected.col = clipped[i].col;
+                    triProjected.T = clipped[i].T;
+                    triProjected.U = clipped[i].U;
+                    triProjected.V = clipped[i].V;
 
                     triProjected.A = Vector.divide(triProjected.A, triProjected.A.w);
                     triProjected.B = Vector.divide(triProjected.B, triProjected.B.w);
@@ -205,9 +214,13 @@ public class Panel extends JPanel implements Runnable {
             }
 
             for (Triangle tt : triList) {
-                DrawUtils.FillTriangle(p,(int)tt.A.x,(int)tt.A.y,(int)tt.B.x,(int)tt.B.y,(int)tt.C.x,(int)tt.C.y,tt.getColor());
+                DrawUtils.TexturedTriangle(p, 
+                    (int)tt.A.x,(int)tt.A.y,tt.T.u,tt.T.v,
+                    (int)tt.B.x,(int)tt.B.y,tt.U.u,tt.U.v,
+                    (int)tt.C.x,(int)tt.C.y,tt.V.u,tt.V.v,
+                SigRenderer.dirtTex);
                 if (SigRenderer.WIREFRAME) {
-                    DrawUtils.DrawTriangle(p,(int)tt.A.x,(int)tt.A.y,(int)tt.B.x,(int)tt.B.y,(int)tt.C.x,(int)tt.C.y,Color.BLACK);
+                    DrawUtils.DrawTriangle(p,(int)tt.A.x,(int)tt.A.y,(int)tt.B.x,(int)tt.B.y,(int)tt.C.x,(int)tt.C.y,Color.WHITE);
                 }
             }
         }

src/sig/SigRenderer.java

@@ -1,4 +1,5 @@
 package sig;
+import javax.imageio.ImageIO;
 import javax.swing.JFrame;
 
 import sig.utils.OBJReader;
@@ -6,15 +7,19 @@ import sig.utils.OBJReader;
 import java.awt.event.MouseEvent;
 import java.awt.event.MouseListener; 
 import java.awt.event.MouseMotionListener;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
 import java.awt.event.KeyEvent;
 import java.awt.event.KeyListener;
+import java.util.Arrays;
 import java.util.List;
 import java.awt.Toolkit;
 import java.awt.BorderLayout;
 
 public class SigRenderer implements KeyListener,MouseListener,MouseMotionListener{
 
-    public static boolean WIREFRAME = false;
+    public static boolean WIREFRAME = true;
 
     public static Mesh cube;
     public static int SCREEN_WIDTH=1280;
@@ -40,6 +45,8 @@ public class SigRenderer implements KeyListener,MouseListener,MouseMotionListene
     final float MOVESPEED = 0.03f;
     final float TURNSPEED = 0.03f;
 
+    public static BufferedImage dirtTex;
+
     boolean upHeld=false,downHeld=false,leftHeld=false,rightHeld=false,
     aHeld=false,sHeld=false,dHeld=false,wHeld=false;
 
@@ -74,7 +81,29 @@ public class SigRenderer implements KeyListener,MouseListener,MouseMotionListene
     }
 
     SigRenderer(JFrame f) {
-        cube = new Mesh(OBJReader.ReadOBJFile("teapot.obj"));
+
+        try {
+            dirtTex = ImageIO.read(new File("dirt.png"));
+        } catch (IOException e1) {
+            e1.printStackTrace();
+        }
+
+        //cube = new Mesh(OBJReader.ReadOBJFile("teapot.obj"));
+        cube = new Mesh(Arrays.asList(
+            new Triangle[]{
+                new Triangle(new Vector(),new Vector(0,1,0),new Vector(1,1,0),new Vector2(0,1),new Vector2(0,0),new Vector2(1,0)),
+                new Triangle(new Vector(),new Vector(1,1,0),new Vector(1,0,0),new Vector2(0,1),new Vector2(1,0),new Vector2(1,1)),
+                new Triangle(new Vector(1,0,0),new Vector(1,1,0),new Vector(1,1,1),new Vector2(0,1),new Vector2(0,0),new Vector2(1,0)),
+                new Triangle(new Vector(1,0,0),new Vector(1,1,1),new Vector(1,0,1),new Vector2(0,1),new Vector2(1,0),new Vector2(1,1)),
+                new Triangle(new Vector(1,0,1),new Vector(1,1,1),new Vector(0,1,1),new Vector2(0,1),new Vector2(0,0),new Vector2(1,0)),
+                new Triangle(new Vector(1,0,1),new Vector(0,1,1),new Vector(0,0,1),new Vector2(0,1),new Vector2(1,0),new Vector2(1,1)),
+                new Triangle(new Vector(0,0,1),new Vector(0,1,1),new Vector(0,1,0),new Vector2(0,1),new Vector2(0,0),new Vector2(1,0)),
+                new Triangle(new Vector(0,0,1),new Vector(0,1,0),new Vector(0,0,0),new Vector2(0,1),new Vector2(1,0),new Vector2(1,1)),
+                new Triangle(new Vector(0,1,0),new Vector(0,1,1),new Vector(1,1,1),new Vector2(0,1),new Vector2(0,0),new Vector2(1,0)),
+                new Triangle(new Vector(0,1,0),new Vector(1,1,1),new Vector(1,1,0),new Vector2(0,1),new Vector2(1,0),new Vector2(1,1)),
+                new Triangle(new Vector(1,0,1),new Vector(0,0,1),new Vector(0,0,0),new Vector2(0,1),new Vector2(0,0),new Vector2(1,0)),
+                new Triangle(new Vector(1,0,1),new Vector(0,0,0),new Vector(1,0,0),new Vector2(0,1),new Vector2(1,0),new Vector2(1,1)),
+            }));
 
         Panel p = new Panel();
 

src/sig/Triangle.java

@@ -1,17 +1,23 @@
 package sig;
 import java.awt.Color;
-import java.util.Arrays;
 
 public class Triangle {
     Vector A,B,C;
+    Vector2 T,U,V;
     Color col = Color.WHITE;
     public Triangle() {
         this(new Vector(),new Vector(),new Vector());
     }
     public Triangle(Vector A,Vector B,Vector C) {
+        this(A,B,C,new Vector2(),new Vector2(),new Vector2());
+    }
+    public Triangle(Vector A,Vector B,Vector C,Vector2 T,Vector2 U,Vector2 V) {
         this.A=A;
         this.B=B;
         this.C=C;
+        this.T=T;
+        this.U=U;
+        this.V=V;
     }
     @Override
     protected Object clone(){
@@ -38,7 +44,10 @@ public class Triangle {
         plane_n = Vector.normalize(plane_n);
         Vector[] inside_points = new Vector[]{new Vector(),new Vector(),new Vector()};
         Vector[] outside_points = new Vector[]{new Vector(),new Vector(),new Vector()};
+        Vector2[] inside_tex = new Vector2[]{new Vector2(),new Vector2(),new Vector2()};
+        Vector2[] outside_tex = new Vector2[]{new Vector2(),new Vector2(),new Vector2()};
         int insidePointCount=0,outsidePointCount=0;
+        int insideTexCount=0,outsideTexCount=0;
 
         float d0=dist(plane_p,plane_n,in.A);
         float d1=dist(plane_p,plane_n,in.B);
@@ -46,18 +55,24 @@ public class Triangle {
 
         if (d0>=0) {
             inside_points[insidePointCount++]=in.A;
+            inside_tex[insideTexCount++]=in.T;
         } else {
             outside_points[outsidePointCount++]=in.A;
+            outside_tex[outsideTexCount++]=in.T;
         }
         if (d1>=0) {
             inside_points[insidePointCount++]=in.B;
+            inside_tex[insideTexCount++]=in.U;
         } else {
             outside_points[outsidePointCount++]=in.B;
+            outside_tex[outsideTexCount++]=in.U;
         }
         if (d2>=0) {
             inside_points[insidePointCount++]=in.C;
+            inside_tex[insideTexCount++]=in.V;
         } else {
             outside_points[outsidePointCount++]=in.C;
+            outside_tex[outsideTexCount++]=in.V;
         }
 
         if (insidePointCount==0) {
@@ -68,20 +83,35 @@ public class Triangle {
             return 1;
         } else
         if (insidePointCount==1&&outsidePointCount==2) {
+            ExtraData t = new ExtraData(0);
             out_tri[0].col = in.col;
             out_tri[0].A = inside_points[0];
-            out_tri[0].B = Vector.IntersectPlane(plane_p, plane_n, inside_points[0], outside_points[0]);
+            out_tri[0].T = inside_tex[0];
-            out_tri[0].C = Vector.IntersectPlane(plane_p, plane_n, inside_points[0], outside_points[1]);
+            out_tri[0].B = Vector.IntersectPlane(plane_p, plane_n, inside_points[0], outside_points[0],t);
+            out_tri[0].U.u = t.t*(outside_tex[0].u-inside_tex[0].u)+inside_tex[0].u;
+            out_tri[0].U.v = t.t*(outside_tex[0].v-inside_tex[0].v)+inside_tex[0].v;
+            out_tri[0].C = Vector.IntersectPlane(plane_p, plane_n, inside_points[0], outside_points[1],t);
+            out_tri[0].V.u = t.t*(outside_tex[1].u-inside_tex[0].u)+inside_tex[0].u;
+            out_tri[0].V.v = t.t*(outside_tex[1].v-inside_tex[0].v)+inside_tex[0].v;
             return 1;
         } else
         if (insidePointCount==2&&outsidePointCount==1) {
+            ExtraData t = new ExtraData(0);
             out_tri[0].col=out_tri[1].col=in.col;
             out_tri[0].A = inside_points[0];
             out_tri[0].B = inside_points[1];
-            out_tri[0].C = Vector.IntersectPlane(plane_p, plane_n, inside_points[0], outside_points[0]);
+            out_tri[0].T = inside_tex[0];
+            out_tri[0].U = inside_tex[1];
+            out_tri[0].C = Vector.IntersectPlane(plane_p, plane_n, inside_points[0], outside_points[0],t);
+            out_tri[0].V.u = t.t*(outside_tex[0].u-inside_tex[0].u)+inside_tex[0].u;
+            out_tri[0].V.v = t.t*(outside_tex[0].v-inside_tex[0].v)+inside_tex[0].v;
             out_tri[1].A = inside_points[1];
+            out_tri[1].T = inside_tex[1];
             out_tri[1].B = out_tri[0].C;
-            out_tri[1].C = Vector.IntersectPlane(plane_p, plane_n, inside_points[1], outside_points[0]);
+            out_tri[1].U = out_tri[0].V;
+            out_tri[1].C = Vector.IntersectPlane(plane_p, plane_n, inside_points[1], outside_points[0],t);
+            out_tri[1].V.u = t.t*(outside_tex[0].u-inside_tex[1].u)+inside_tex[1].u;
+            out_tri[1].V.v = t.t*(outside_tex[0].v-inside_tex[1].v)+inside_tex[1].v;
             return 2;
         }
 

src/sig/Vector.java

@@ -53,12 +53,13 @@ public class Vector {
     public String toString() {
         return "Vector ["+x+","+y+","+z+","+w+"]";
     }
-    public static Vector IntersectPlane(Vector plane_p,Vector plane_n,Vector lineStart,Vector lineEnd) {
+    public static Vector IntersectPlane(Vector plane_p,Vector plane_n,Vector lineStart,Vector lineEnd,ExtraData tt) {
         plane_n = Vector.normalize(plane_n);
         float plane_d = -Vector.dotProduct(plane_n,plane_p);
         float ad = Vector.dotProduct(lineStart,plane_n);
         float bd = Vector.dotProduct(lineEnd,plane_n);
         float t = (-plane_d-ad)/(bd-ad);
+        tt.t=t;
         Vector lineStartToEnd = Vector.subtract(lineEnd,lineStart);
         Vector lineToIntersect = Vector.multiply(lineStartToEnd,t);
         return Vector.add(lineStart,lineToIntersect);

src/sig/Vector2.java

@@ -0,0 +1,12 @@
+package sig;
+
+public class Vector2 {
+    public float u,v;
+    Vector2() {
+        this(0,0);
+    }
+    public Vector2(float u,float v) {
+        this.u=u;
+        this.v=v;
+    }
+}

src/sig/utils/DrawUtils.java

@@ -2,6 +2,7 @@ package sig.utils;
 
 import java.awt.Color;
 import java.util.Arrays;
+import java.awt.image.BufferedImage;
 
 import sig.SigRenderer;
 
@@ -11,6 +12,111 @@ public class DrawUtils {
             Draw(canvas,i,ny,col);
         }
     }
+    public static void TexturedTriangle(int[] canvas,
+            int x1, int y1, float u1,float v1,
+            int x2, int y2, float u2,float v2,
+            int x3, int y3, float u3,float v3,
+            BufferedImage texture
+    ) {
+		if (y2<y1) {int t=y1;y1=y2;y2=t;t=x1;x1=x2;x2=t;float u=u1;u1=u2;u2=u;float v=v1;v1=v2;v2=v;}
+		if (y3<y1) {int t=y1;y1=y3;y3=t;t=x1;x1=x3;x3=t;float u=u1;u1=u3;u3=u;float v=v1;v1=v3;v3=v;}
+		if (y3<y2) {int t=y2;y2=y3;y3=t;t=x2;x2=x3;x3=t;float u=u2;u2=u3;u3=u;float v=v2;v2=v3;v3=v;}
+
+        int dy1=y2-y1;
+        int dx1=x2-x1;
+        float dv1=v2-v1;
+        float du1=u2-u1;
+        int dy2=y3-y1;
+        int dx2=x3-x1;
+        float dv2=v3-v1;
+        float du2=u3-u1;
+        float tex_u,tex_v;
+
+        float dax_step=0,dbx_step=0,
+            du1_step=0,dv1_step=0,
+            du2_step=0,dv2_step=0;
+
+        if (dy1!=0) {dax_step=dx1/(float)Math.abs(dy1);}
+        if (dy2!=0) {dbx_step=dx2/(float)Math.abs(dy2);}
+
+        if (dy1!=0) {du1_step=du1/(float)Math.abs(dy1);}
+        if (dy1!=0) {dv1_step=dv1/(float)Math.abs(dy1);}
+        if (dy2!=0) {du2_step=du2/(float)Math.abs(dy2);}
+        if (dy2!=0) {dv2_step=dv2/(float)Math.abs(dy2);}
+
+        if (dy1!=0) {
+            for (int i=y1;i<=y2;i++) {
+                int ax=(int)(x1+(float)(i-y1)*dax_step);
+                int bx=(int)(x1+(float)(i-y1)*dbx_step);
+
+                float tex_su=(int)(u1+(float)(i-y1)*du1_step);
+                float tex_sv=(int)(v1+(float)(i-y1)*dv1_step);
+                float tex_eu=(int)(u1+(float)(i-y1)*du2_step);
+                float tex_ev=(int)(v1+(float)(i-y1)*dv2_step);
+
+                if (ax>bx) {
+                    int t=ax;ax=bx;bx=t;
+                    float u=tex_su;tex_su=tex_eu;tex_eu=u;
+                    float v=tex_sv;tex_sv=tex_ev;tex_ev=v;
+                }
+
+                tex_u=tex_su;
+                tex_v=tex_sv;
+
+                float tstep = 1.0f/((float)(bx-ax));
+                float t=0.0f;
+
+                for (int j=ax;j<bx;j++) {
+                    tex_u=(1.0f-t)*tex_su+t*tex_eu;
+                    tex_v=(1.0f-t)*tex_sv+t*tex_ev;
+                    Draw(canvas,j,i,new Color(texture.getRGB((int)Math.max(0,tex_u*(texture.getWidth()-1)),(int)Math.max(0,tex_v*(texture.getHeight()-1)))));
+                    t+=tstep;
+                }
+            }
+        }
+
+        dy1=y3-y2;
+        dx1=x3-x2;
+        dv1=v3-v2;
+        du1=u3-u2;
+        if (dy1!=0) {dax_step=dx1/(float)Math.abs(dy1);}
+        if (dy2!=0) {dbx_step=dx2/(float)Math.abs(dy2);}
+        du1_step=0f;
+        dv1_step=0f;
+        if (dy1!=0) {du1_step=du1/(float)Math.abs(dy1);}
+        if (dy1!=0) {dv1_step=dv1/(float)Math.abs(dy1);}
+
+        if (dy1!=0) {
+            for (int i=y2;i<=y3;i++) {
+                int ax=(int)(x2+(float)(i-y2)*dax_step);
+                int bx=(int)(x1+(float)(i-y1)*dbx_step);
+
+                float tex_su=(int)(u2+(float)(i-y2)*du1_step);
+                float tex_sv=(int)(v2+(float)(i-y2)*dv1_step);
+                float tex_eu=(int)(u1+(float)(i-y1)*du2_step);
+                float tex_ev=(int)(v1+(float)(i-y1)*dv2_step);
+
+                if (ax>bx) {
+                    int t=ax;ax=bx;bx=t;
+                    float u=tex_su;tex_su=tex_eu;tex_eu=u;
+                    float v=tex_sv;tex_sv=tex_ev;tex_ev=v;
+                }
+
+                tex_u=tex_su;
+                tex_v=tex_sv;
+
+                float tstep = 1.0f/((float)(bx-ax));
+                float t=0.0f;
+
+                for (int j=ax;j<bx;j++) {
+                    tex_u=(1.0f-t)*tex_su+t*tex_eu;
+                    tex_v=(1.0f-t)*tex_sv+t*tex_ev;
+                    Draw(canvas,j,i,new Color(texture.getRGB((int)Math.max(0,tex_u*(texture.getWidth()-1)),(int)Math.max(0,tex_v*(texture.getHeight()-1)))));
+                    t+=tstep;
+                }
+            }
+        }
+    }
     public static void FillTriangle(int[] canvas,int x1, int y1, int x2, int y2, int x3, int y3, Color col)
 	{
 		int t1x=0, t2x=0, y=0, minx=0, maxx=0, t1xp=0, t2xp=0;