Added visible poly list and painters algorithm. Something is very broken.

j3d/build-All.sh

@@ -2,7 +2,7 @@
 
 PROJECT=j3d
 GAME=${JOEY}/j3d/j3d
-DATA=(${GAME}/cube.j3d ${GAME}/font.sta)
+DATA=(${GAME}/cube.j3d ${GAME}/pyramid.j3d ${GAME}/font.sta)
 #SOURCE=(*.c *.h)
 SOURCE=()
 

j3d/j3d.c

@@ -55,21 +55,32 @@ segment "j3d";
 #endif
 
 
+typedef int (*j3qsortCastT)(const void *, const void *);
+
+
+int _j3PolyCompare(j3PolyListT *arg1, j3PolyListT *arg2);
+
+
 // Module global data
-jint16       _j3VarClipMinX            = 0;
-jint16       _j3VarClipMinY            = 0;
-jint16       _j3VarClipMinZ            = 100;
-jint16       _j3VarClipMaxX            = 319;
-jint16       _j3VarClipMaxY            = 199;
-jint16       _j3VarClipMaxZ            = 3000;
-jint16       _j3VarViewDistance        = 250;
-float        _j3VarAmbientLight        = 6;
-j3Matrix4x4T _j3VarCameraMatrix;
-j3VertexT    _j3VarCameraLocation;
-j3FacingT    _j3VarCameraAngle;
-bool         _j3VarCameraLocationDirty = true;
-bool         _j3VarCameraAngleDirty    = true;
-j3VertexT    _j3VarSunLocation;
+jint16        _j3VarClipMinX            = 0;
+jint16        _j3VarClipMinY            = 0;
+jint16        _j3VarClipMinZ            = 100;
+jint16        _j3VarClipMaxX            = 319;
+jint16        _j3VarClipMaxY            = 199;
+jint16        _j3VarClipMaxZ            = 3000;
+jint16        _j3VarViewDistance        = 200;
+float         _j3VarAmbientLight        = 6;
+j3Matrix4x4T  _j3VarCameraMatrix;
+j3VertexT     _j3VarCameraLocation;
+j3FacingT     _j3VarCameraAngle;
+bool          _j3VarCameraLocationDirty = true;
+bool          _j3VarCameraAngleDirty    = true;
+j3VertexT     _j3VarSunLocation;
+
+//***TODO*** None of this should be global - put inside world
+j3PolyListT  *_j3Polygons               = NULL;
+juint16       _j3PolygonCount           = 0;      // Current visible polygons
+juint16       _j3TriangleCount          = 0;      // Current triangles in world
 
 
 #define ASPECT_RATIO          (float)0.8
@@ -404,6 +415,65 @@ void _j3DrawWireframe(j3ObjectT *o) {
 }
 
 
+void j3DrawWorld(j3WorldT *w) {
+	jint16       i;
+	juint16      vertex1;
+	juint16      vertex2;
+	juint16      vertex3;
+	float        x1;
+	float        y1;
+	float        z1;
+	float        x2;
+	float        y2;
+	float        z2;
+	float        x3;
+	float        y3;
+	float        z3;
+	j3ObjectT   *o;
+	j3PolyListT *p;
+
+	//***TODO*** Fix
+	(void)w;
+
+	for (i=0; i<_j3PolygonCount; i++) {
+
+		// Dereference
+		p = &_j3Polygons[i];
+		o = p->object;
+
+		vertex1 = o->triangles[p->triangleNumber].index[0];
+		vertex2 = o->triangles[p->triangleNumber].index[1];
+		vertex3 = o->triangles[p->triangleNumber].index[2];
+		z1 = o->verticies[vertex1].camera.z;
+		z2 = o->verticies[vertex2].camera.z;
+		z3 = o->verticies[vertex3].camera.z;
+
+		// Perform z clipping
+		if ((z1 < _j3VarClipMinZ && z2 < _j3VarClipMinZ && z3 < _j3VarClipMinZ) || (z1 > _j3VarClipMaxZ && z2 > _j3VarClipMaxZ && z3 > _j3VarClipMaxZ)) {
+			continue;
+		}
+
+		// Extract points of triangle
+		x1 = o->verticies[vertex1].camera.x;
+		y1 = o->verticies[vertex1].camera.y;
+		x2 = o->verticies[vertex2].camera.x;
+		y2 = o->verticies[vertex2].camera.y;
+		x3 = o->verticies[vertex3].camera.x;
+		y3 = o->verticies[vertex3].camera.y;
+
+		// Screen position of points
+		x1 = HALF_SCREEN_WIDTH  + x1 * _j3VarViewDistance / z1;
+		y1 = HALF_SCREEN_HEIGHT - ASPECT_RATIO * y1 * _j3VarViewDistance / z1;
+		x2 = HALF_SCREEN_WIDTH  + x2 * _j3VarViewDistance / z2;
+		y2 = HALF_SCREEN_HEIGHT - ASPECT_RATIO * y2 * _j3VarViewDistance / z2;
+		x3 = HALF_SCREEN_WIDTH  + x3 * _j3VarViewDistance / z3;
+		y3 = HALF_SCREEN_HEIGHT - ASPECT_RATIO * y3 * _j3VarViewDistance / z3;
+
+		j3DrawTriangle2D((jint16)x1, (jint16)y1, (jint16)x2, (jint16)y2, (jint16)x3, (jint16)y3, o->triangles[p->triangleNumber].shade);
+	}
+}
+
+
 void j3MathCrossProduct3D(j3Vector3DT *u, j3Vector3DT *v, j3Vector3DT *normal) {
 	// Compute the cross product between two vectors
 	normal->x =  (u->y*v->z - u->z*v->y);
@@ -818,7 +888,23 @@ void _j3ObjectUpdate(j3ObjectT *o) {
 			}
 		}
 
-	}
+		// Did this triangle survive culling?
+		if (o->triangles[i].visible) {
+			// Find average z depth in camera space
+			vertex0 = o->triangles[i].index[0];
+			vertex1 = o->triangles[i].index[1];
+			vertex2 = o->triangles[i].index[2];
+			o->triangles[i].averageDepth = (float)0.3333333 * (o->verticies[vertex0].camera.z + o->verticies[vertex1].camera.z + o->verticies[vertex2].camera.z);
+			// Add to visible polygon list
+			_j3Polygons[_j3PolygonCount].object = o;
+			_j3Polygons[_j3PolygonCount].triangleNumber = (juint16)i;
+			_j3PolygonCount++;
+		}
+
+	} // for i
+
+	// Z Sort the visible polygon list
+	qsort((void *)_j3Polygons, _j3PolygonCount, sizeof(j3PolyListT), (j3qsortCastT)_j3PolyCompare);
 
 	o->positionDirty = false;
 	o->rotationDirty = false;
@@ -852,6 +938,23 @@ void _j3ObjectUpdateNormalLength(j3ObjectT *object, juint16 triangle) {
 }
 
 
+int _j3PolyCompare(j3PolyListT *arg1, j3PolyListT *arg2) {
+	float z1;
+	float z2;
+
+	z1 = arg1->object->triangles[arg1->triangleNumber].averageDepth;
+	z2 = arg2->object->triangles[arg2->triangleNumber].averageDepth;
+
+	if (z1 > z2) {
+		return(-1);
+	} else if (z1 < z2) {
+		return(1);
+	} else {
+		return(0);
+	}
+}
+
+
 bool _j3UtilClipLine(jint16 *x1, jint16 *y1, jint16 *x2, jint16 *y2) {
 	jint16 xi;
 	jint16 yi;
@@ -1042,7 +1145,10 @@ bool _j3UtilClipLine(jint16 *x1, jint16 *y1, jint16 *x2, jint16 *y2) {
 
 
 void j3UtilShutdown(void) {
-	// Nothing yet
+	// Free visible polygon list
+	if (_j3Polygons != NULL) {
+		jlFree(_j3Polygons);
+	}
 }
 
 
@@ -1162,6 +1268,11 @@ bool _j3WorldLoad(j3WorldT **world, char *file) {
 									(*world)->objects->triangles = (j3TriangleT *)jlMalloc(sizeof(j3TriangleT) * (*world)->objects[x].triangleCount);
 									if ((*world)->objects->triangles) {
 
+										//***TODO*** This will have to be moved/improved
+										// Add to world count & increase potential polygon list
+										_j3TriangleCount += (*world)->objects[x].triangleCount;
+										_j3Polygons = (j3PolyListT *)jlRealloc(_j3Polygons, sizeof(j3PolyListT) * _j3TriangleCount);
+
 										// Iterate and read triangles
 										for (y=0; y<(*world)->objects[x].triangleCount; y++) {
 											// Read one at a time in case the struct gets padded

j3d/j3d.h

@@ -54,6 +54,7 @@ typedef struct {
 	bool    visible;       // Can we see this triangle?
 	bool    twoSided;      // Are both sides visible?
 	float   normalLength;  // Magnatude of surface normal
+	float   averageDepth;  // Average Z depth of this triangle
 	juint16 index[3];      // We do this instead of just a typedef so it works with stretch_buffer
 } j3TriangleT;
 
@@ -70,26 +71,34 @@ typedef struct {
 	bool            scaleDirty;     // Did the scale change?
 } j3ObjectT;
 
+typedef struct {
+	j3ObjectT *object;
+	juint16    triangleNumber;
+} j3PolyListT;
+
 typedef struct {
 	juint16    objectCount;
 	j3ObjectT *objects;
 } j3WorldT;
 
 
-extern jint16       _j3VarClipMinX;
-extern jint16       _j3VarClipMinY;
-extern jint16       _j3VarClipMinZ;
-extern jint16       _j3VarClipMaxX;
-extern jint16       _j3VarClipMaxY;
-extern jint16       _j3VarClipMaxZ;
-extern jint16       _j3VarViewDistance;
-extern float        _j3VarAmbientLight;
-extern j3Matrix4x4T _j3VarCameraMatrix;
-extern j3VertexT    _j3VarCameraLocation;
-extern j3FacingT    _j3VarCameraAngle;
-extern bool         _j3VarCameraLocationDirty;
-extern bool         _j3VarCameraAngleDirty;
-extern j3VertexT    _j3VarSunLocation;
+extern jint16        _j3VarClipMinX;
+extern jint16        _j3VarClipMinY;
+extern jint16        _j3VarClipMinZ;
+extern jint16        _j3VarClipMaxX;
+extern jint16        _j3VarClipMaxY;
+extern jint16        _j3VarClipMaxZ;
+extern jint16        _j3VarViewDistance;
+extern float         _j3VarAmbientLight;
+extern j3Matrix4x4T  _j3VarCameraMatrix;
+extern j3VertexT     _j3VarCameraLocation;
+extern j3FacingT     _j3VarCameraAngle;
+extern bool          _j3VarCameraLocationDirty;
+extern bool          _j3VarCameraAngleDirty;
+extern j3VertexT     _j3VarSunLocation;
+extern j3PolyListT  *_j3Polygons;
+extern juint16       _j3PolygonCount;
+extern juint16       _j3TriangleCount;
 
 
 #define j3CameraMove(ob, px, py, pz) \
@@ -178,6 +187,7 @@ extern j3VertexT    _j3VarSunLocation;
 
 // Prototypes
 void  j3DrawTriangle2D(jint16 x1, jint16 y1, jint16 x2,jint16 y2, jint16 x3, jint16 y3, jint16 color);
+void  j3DrawWorld(j3WorldT *w);
 void  j3MathCrossProduct3D(j3Vector3DT *u, j3Vector3DT *v, j3Vector3DT *normal);
 float j3MathDotProduct3D(j3Vector3DT *u, j3Vector3DT *v);
 void  j3MathMatrix4x4Identity(j3Matrix4x4T result);

j3d/main.c

@@ -74,7 +74,7 @@ int main(void) {
 
 	printAt(font, 1, 1, "Loading object...    ");
 	jlDisplayPresent();
-	r = j3WorldLoad(world, "cube");
+	r = j3WorldLoad(world, "pyramid");
 	if (!r) {
 		printAt(font, 1, 1, "Object loading:  Failed.");
 		jlDisplayPresent();
@@ -130,11 +130,15 @@ int main(void) {
 			jlDrawColor(15);
 			jlDrawBox(0, 0, 319, 199);
 
+			//***TODO*** HACK!!!
+			_j3PolygonCount = 0;
+
 			for (x=0; x<world->objectCount; x++) {
 				j3ObjectRotate(world->objects[x], 2, 4, 6);  // Matching values in code I'm studying
 				j3ObjectUpdate(world->objects[x]);
 				//j3DrawWireframe(world->objects[x]);
-				j3DrawSolid(world->objects[x]);
+				//j3DrawSolid(world->objects[x]);
+				j3DrawWorld(world);
 			}
 
 			c = 0;
@@ -148,6 +152,7 @@ int main(void) {
 			printAt(font, 1, 2, "Triangles:  %d (%d visible) ", world->objects[0].triangleCount, c);
 
 			jlDisplayPresent();
+			jlUtilSleep(1);
 		}
 		jlKeyRead();
 	}

j3d/pyramid.obj

+v 0 30 0
+v 30 -10 30
+v 30 -10 -30
+v -30 -10 -30
+v -30 -10 30
+
+f 1 3 2
+f 1 4 3
+f 1 5 4
+f 1 2 5
+f 5 2 3
+f 3 4 5