Colored and solid objects on IIgs are working.

j3d/j3d.c

@@ -25,6 +25,11 @@
 // https://archive.org/details/BlackArt3DEBook
 
 
+//***TODO***
+// Allow multiple objects to be loaded into a world
+// Store original vertex data so we can do local rotations and save them
+
+
 #include <math.h>
 #include <stdio.h>
 #include <float.h>
@@ -465,6 +470,10 @@ void _j3ObjectReset(j3ObjectT *o) {
 	o->scale.x = 1;
 	o->scale.y = 1;
 	o->scale.z = 1;
+
+	o->positionDirty = true;
+	o->rotationDirty = true;
+	o->scaleDirty    = true;
 }
 
 
@@ -491,6 +500,11 @@ void _j3ObjectUpdate(j3ObjectT *o) {
 
 	// === ROTATION ===
 
+	if (o->rotationDirty) {
+
+		// Rotation being dirty means we also need to update position later
+		o->positionDirty = true;
+
 		x = (jint16)o->rotation.x;
 		y = (jint16)o->rotation.y;
 		z = (jint16)o->rotation.z;
@@ -628,14 +642,17 @@ void _j3ObjectUpdate(j3ObjectT *o) {
 			default:
 				break;
 		}
+	}
 
 	// === SCALE & TRANSLATION ===
 
+	if (o->positionDirty || o->scaleDirty) {
 		for (i=0; i<o->vertexCount; i++) {
 			o->verticies[i].world.x = o->verticies[i].world.x * o->scale.x + o->position.x;
 			o->verticies[i].world.y = o->verticies[i].world.y * o->scale.y + o->position.y;
 			o->verticies[i].world.z = o->verticies[i].world.z * o->scale.z + o->position.z;
 		}
+	}
 
 	// === CAMERA SPACE ===
 	//***TODO*** Move this?
@@ -647,6 +664,10 @@ void _j3ObjectUpdate(j3ObjectT *o) {
 	// === REMOVE BACKFACES & LIGHT ===
 
 	for (i=0; i<o->triangleCount; i++) {
+		// If the scale changed, we need a new normal length
+		if (o->scaleDirty) {
+			_j3ObjectUpdateNormalLength(o, (juint16)i);
+		}
 		// If it's two sided, there are no backfaces
 		if (!o->triangles[i].twoSided) {
 
@@ -740,6 +761,36 @@ void _j3ObjectUpdate(j3ObjectT *o) {
 		}
 
 	}
+
+	o->positionDirty = false;
+	o->rotationDirty = false;
+	o->scaleDirty    = false;
+}
+
+
+void _j3ObjectUpdateNormalLength(j3ObjectT *object, juint16 triangle) {
+	juint16         vertex0;
+	juint16         vertex1;
+	juint16         vertex2;
+	j3Vector3DT     u;
+	j3Vector3DT     v;
+	j3Vector3DT     normal;
+
+	// Compute length of the two co-planer edges of the polygon, since they will be used in the computation of the dot-product later
+	vertex0 = object->triangles[triangle].index[0];
+	vertex1 = object->triangles[triangle].index[1];
+	vertex2 = object->triangles[triangle].index[2];
+
+	j3MathMakeVector3D((j3VertexT *)&object->verticies[vertex0].local, (j3VertexT *)&object->verticies[vertex1].local, (j3Vector3DT *)&u);
+	j3MathMakeVector3D((j3VertexT *)&object->verticies[vertex0].local, (j3VertexT *)&object->verticies[vertex2].local, (j3Vector3DT *)&v);
+	j3MathCrossProduct3D((j3Vector3DT *)&v, (j3Vector3DT *)&u, (j3Vector3DT *)&normal);
+
+	// Compute magnitude of normal, take its inverse and multiply it by
+	// 15, this will change the shading calculation of 15*dp/normal into
+	// dp*normal_length, removing one division
+	object->triangles[triangle].normalLength = (float)15.0 / j3MathVectorMagnatude3D((j3Vector3DT *)&normal);
+
+
 }
 
 
@@ -973,15 +1024,9 @@ void _j3WorldFree(j3WorldT **world) {
 
 
 bool _j3WorldLoad(j3WorldT **world, char *file) {
-	jint16          x;
+	juint16         x;
-	jint16          y;
+	juint16         y;
-	jint16          z;
+	juint16         z;
-	juint16         vertex0;
-	juint16         vertex1;
-	juint16         vertex2;
-	j3Vector3DT     u;
-	j3Vector3DT     v;
-	j3Vector3DT     normal;
 	byte            buffer[4];
 	FILE           *in;
 	bool            failed = false;
@@ -1070,21 +1115,16 @@ bool _j3WorldLoad(j3WorldT **world, char *file) {
 											}
 											if (failed) break;
 
-											// Compute length of the two co-planer edges of the polygon, since they will be used in the computation of the dot-product later
+											_j3ObjectUpdateNormalLength(&(*world)->objects[x], y);
-											vertex0 = (*world)->objects[x].triangles[y].index[0];
-											vertex1 = (*world)->objects[x].triangles[y].index[1];
-											vertex2 = (*world)->objects[x].triangles[y].index[2];
-											j3MathMakeVector3D((j3VertexT *)&(*world)->objects[x].verticies[vertex0].local, (j3VertexT *)&(*world)->objects[x].verticies[vertex1].local, (j3Vector3DT *)&u);
-											j3MathMakeVector3D((j3VertexT *)&(*world)->objects[x].verticies[vertex0].local, (j3VertexT *)&(*world)->objects[x].verticies[vertex2].local, (j3Vector3DT *)&v);
-											j3MathCrossProduct3D((j3Vector3DT *)&v, (j3Vector3DT *)&u, (j3Vector3DT *)&normal);
 
-											// Compute magnitude of normal, take its inverse and multiply it by
+											// Triangles begin life un-lit
-											// 15, this will change the shading calculation of 15*dp/normal into
+											(*world)->objects[x].triangles[y].lit = false;
-											// dp*normal_length, removing one division
-											(*world)->objects[x].triangles[y].normalLength = (float)15.0 / j3MathVectorMagnatude3D((j3Vector3DT *)&normal);
 
 											//***TODO*** All triangles are one-sided for now
 											(*world)->objects[x].triangles[y].twoSided = false;
+
+											//***TODO*** All triangles are white for now
+											(*world)->objects[x].triangles[y].color = 15;
 										}
 
 									} else {

j3d/j3d.h

@@ -68,6 +68,9 @@ typedef struct {
 	j3VertexT       position;       // Position of object in world
 	j3VertexT       rotation;       // Rotation of object in world
 	j3VertexT       scale;          // Scale of object in world
+	bool            positionDirty;  // Did the position change?
+	bool            rotationDirty;  // Did the rotation change?
+	bool            scaleDirty;     // Did the scale change?
 } j3ObjectT;
 
 typedef struct {
@@ -93,32 +96,38 @@ typedef struct {
 #define j3ObjectMove(ob, px, py, pz) \
 	ob.position.x += (px);  \
 	ob.position.y += (py);  \
-	ob.position.z += (pz)
+	ob.position.z += (pz);  \
+	ob.positionDirty = true
 
 #define j3ObjectMoveTo(ob, px, py, pz)  \
 	ob.position.x = (px);   \
 	ob.position.y = (py);   \
-	ob.position.z = (pz)
+	ob.position.z = (pz);   \
+	ob.positionDirty = true
 
 #define j3ObjectRotate(ob, px, py, pz) \
 	ob.rotation.x += (px);  j3MathWrapBounds(ob.rotation.x, 0, 360);  \
 	ob.rotation.y += (py);  j3MathWrapBounds(ob.rotation.y, 0, 360);  \
-	ob.rotation.z += (pz);  j3MathWrapBounds(ob.rotation.z, 0, 360)
+	ob.rotation.z += (pz);  j3MathWrapBounds(ob.rotation.z, 0, 360);  \
+	ob.rotationDirty = true
 
 #define j3ObjectRotateTo(ob, px, py, pz) \
 	ob.rotation.x = (px);  j3MathWrapBounds(ob.rotation.x, 0, 360);  \
 	ob.rotation.y = (py);  j3MathWrapBounds(ob.rotation.y, 0, 360);  \
-	ob.rotation.z = (pz);  j3MathWrapBounds(ob.rotation.z, 0, 360)
+	ob.rotation.z = (pz);  j3MathWrapBounds(ob.rotation.z, 0, 360);  \
+	ob.rotationDirty = true
 
 #define j3ObjectScale(ob, px, py, pz)  \
 	ob.scale.x += (px);  \
 	ob.scale.y += (py);  \
-	ob.scale.z += (pz)
+	ob.scale.z += (pz);  \
+	ob.scaleDirty = true
 
 #define j3ObjectScaleTo(ob, px, py, pz)  \
 	ob.scale.x = (px);  \
 	ob.scale.y = (py);  \
-	ob.scale.z = (pz)
+	ob.scale.z = (pz);  \
+	ob.scaleDirty = true
 
 
 // Syntatic sugar
@@ -149,6 +158,7 @@ void _j3DrawTriangleTop(jint16 x1, jint16 y1, jint16 x2,jint16 y2, jint16 x3, ji
 void _j3DrawWireframePair(j3ObjectT *o, juint16 v1, juint16 v2);
 void _j3DrawWireframe(j3ObjectT *o);
 void _j3ObjectReset(j3ObjectT *o);
+void _j3ObjectUpdateNormalLength(j3ObjectT *object, juint16 triangle);
 void _j3ObjectUpdate(j3ObjectT *o);
 bool _j3UtilClipLine(jint16 *x1, jint16 *y1, jint16 *x2, jint16 *y2);
 void _j3WorldFree(j3WorldT **world);

j3d/main.c

@@ -87,7 +87,7 @@ int main(void) {
 		c = 1;
 		for (x=0; x<world->objectCount; x++) {
 			for (y=0; y<world->objects[x].triangleCount; y++) {
-				world->objects[x].triangles->color = c++;
+				world->objects[x].triangles[y].color = c++;
 				if (c > 15) {
 					c = 1;
 				}
@@ -137,8 +137,15 @@ int main(void) {
 				j3DrawSolid(world->objects[x]);
 			}
 
+			c = 0;
+			for (x=0; x<world->objects[0].triangleCount; x++) {
+				if (world->objects[0].triangles[x].visible) {
+					c++;
+				}
+			}
+
 			printAt(font, 1, 1, "Verticies:  %d", world->objects[0].vertexCount);
-			printAt(font, 1, 2, "Triangles:  %d", world->objects[0].triangleCount);
+			printAt(font, 1, 2, "Triangles:  %d (%d visible) ", world->objects[0].triangleCount, c);
 
 			jlDisplayPresent();
 		}