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authorKenneth Russel <[email protected]>2005-10-24 19:21:03 +0000
committerKenneth Russel <[email protected]>2005-10-24 19:21:03 +0000
commitd6f9dbc493df725d3d574403549de142c5e1222a (patch)
tree8eb152b0627f8d1897a27c5204d6ce2efb4963e4 /src/classes/com/sun/opengl/impl/tessellator/Render.java
parent42843c3290d64c41c9c8a18b93f5ad3c00d35ddc (diff)
Merged JSR-231 branch on to the main JOGL trunk. The main trunk now
contains the evolving JSR-231 Reference Implementation and the JSR-231 branch is permanently closed. git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/svn-server-sync/jogl/trunk@401 232f8b59-042b-4e1e-8c03-345bb8c30851
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diff --git a/src/classes/com/sun/opengl/impl/tessellator/Render.java b/src/classes/com/sun/opengl/impl/tessellator/Render.java
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+/*
+* Portions Copyright (C) 2003 Sun Microsystems, Inc.
+* All rights reserved.
+*/
+
+/*
+** License Applicability. Except to the extent portions of this file are
+** made subject to an alternative license as permitted in the SGI Free
+** Software License B, Version 1.1 (the "License"), the contents of this
+** file are subject only to the provisions of the License. You may not use
+** this file except in compliance with the License. You may obtain a copy
+** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
+** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
+**
+** http://oss.sgi.com/projects/FreeB
+**
+** Note that, as provided in the License, the Software is distributed on an
+** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
+** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
+** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
+** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
+**
+** Original Code. The Original Code is: OpenGL Sample Implementation,
+** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
+** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
+** Copyright in any portions created by third parties is as indicated
+** elsewhere herein. All Rights Reserved.
+**
+** Additional Notice Provisions: The application programming interfaces
+** established by SGI in conjunction with the Original Code are The
+** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
+** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
+** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
+** Window System(R) (Version 1.3), released October 19, 1998. This software
+** was created using the OpenGL(R) version 1.2.1 Sample Implementation
+** published by SGI, but has not been independently verified as being
+** compliant with the OpenGL(R) version 1.2.1 Specification.
+**
+** Author: Eric Veach, July 1994
+** Java Port: Pepijn Van Eeckhoudt, July 2003
+** Java Port: Nathan Parker Burg, August 2003
+*/
+package com.sun.opengl.impl.tessellator;
+
+import javax.media.opengl.*;
+import javax.media.opengl.glu.*;
+
+class Render {
+ private static final boolean USE_OPTIMIZED_CODE_PATH = false;
+
+ private Render() {
+ }
+
+ private static final RenderFan renderFan = new RenderFan();
+ private static final RenderStrip renderStrip = new RenderStrip();
+ private static final RenderTriangle renderTriangle = new RenderTriangle();
+
+/* This structure remembers the information we need about a primitive
+ * to be able to render it later, once we have determined which
+ * primitive is able to use the most triangles.
+ */
+ private static class FaceCount {
+ public FaceCount() {
+ }
+
+ public FaceCount(long size, com.sun.opengl.impl.tessellator.GLUhalfEdge eStart, renderCallBack render) {
+ this.size = size;
+ this.eStart = eStart;
+ this.render = render;
+ }
+
+ long size; /* number of triangles used */
+ com.sun.opengl.impl.tessellator.GLUhalfEdge eStart; /* edge where this primitive starts */
+ renderCallBack render;
+ };
+
+ private static interface renderCallBack {
+ void render(GLUtessellatorImpl tess, com.sun.opengl.impl.tessellator.GLUhalfEdge e, long size);
+ }
+
+ /************************ Strips and Fans decomposition ******************/
+
+/* __gl_renderMesh( tess, mesh ) takes a mesh and breaks it into triangle
+ * fans, strips, and separate triangles. A substantial effort is made
+ * to use as few rendering primitives as possible (ie. to make the fans
+ * and strips as large as possible).
+ *
+ * The rendering output is provided as callbacks (see the api).
+ */
+ public static void __gl_renderMesh(GLUtessellatorImpl tess, com.sun.opengl.impl.tessellator.GLUmesh mesh) {
+ com.sun.opengl.impl.tessellator.GLUface f;
+
+ /* Make a list of separate triangles so we can render them all at once */
+ tess.lonelyTriList = null;
+
+ for (f = mesh.fHead.next; f != mesh.fHead; f = f.next) {
+ f.marked = false;
+ }
+ for (f = mesh.fHead.next; f != mesh.fHead; f = f.next) {
+
+ /* We examine all faces in an arbitrary order. Whenever we find
+ * an unprocessed face F, we output a group of faces including F
+ * whose size is maximum.
+ */
+ if (f.inside && !f.marked) {
+ RenderMaximumFaceGroup(tess, f);
+ assert (f.marked);
+ }
+ }
+ if (tess.lonelyTriList != null) {
+ RenderLonelyTriangles(tess, tess.lonelyTriList);
+ tess.lonelyTriList = null;
+ }
+ }
+
+
+ static void RenderMaximumFaceGroup(GLUtessellatorImpl tess, com.sun.opengl.impl.tessellator.GLUface fOrig) {
+ /* We want to find the largest triangle fan or strip of unmarked faces
+ * which includes the given face fOrig. There are 3 possible fans
+ * passing through fOrig (one centered at each vertex), and 3 possible
+ * strips (one for each CCW permutation of the vertices). Our strategy
+ * is to try all of these, and take the primitive which uses the most
+ * triangles (a greedy approach).
+ */
+ com.sun.opengl.impl.tessellator.GLUhalfEdge e = fOrig.anEdge;
+ FaceCount max = new FaceCount();
+ FaceCount newFace = new FaceCount();
+
+ max.size = 1;
+ max.eStart = e;
+ max.render = renderTriangle;
+
+ if (!tess.flagBoundary) {
+ newFace = MaximumFan(e);
+ if (newFace.size > max.size) {
+ max = newFace;
+ }
+ newFace = MaximumFan(e.Lnext);
+ if (newFace.size > max.size) {
+ max = newFace;
+ }
+ newFace = MaximumFan(e.Onext.Sym);
+ if (newFace.size > max.size) {
+ max = newFace;
+ }
+
+ newFace = MaximumStrip(e);
+ if (newFace.size > max.size) {
+ max = newFace;
+ }
+ newFace = MaximumStrip(e.Lnext);
+ if (newFace.size > max.size) {
+ max = newFace;
+ }
+ newFace = MaximumStrip(e.Onext.Sym);
+ if (newFace.size > max.size) {
+ max = newFace;
+ }
+ }
+ max.render.render(tess, max.eStart, max.size);
+ }
+
+
+/* Macros which keep track of faces we have marked temporarily, and allow
+ * us to backtrack when necessary. With triangle fans, this is not
+ * really necessary, since the only awkward case is a loop of triangles
+ * around a single origin vertex. However with strips the situation is
+ * more complicated, and we need a general tracking method like the
+ * one here.
+ */
+ private static boolean Marked(com.sun.opengl.impl.tessellator.GLUface f) {
+ return !f.inside || f.marked;
+ }
+
+ private static GLUface AddToTrail(com.sun.opengl.impl.tessellator.GLUface f, com.sun.opengl.impl.tessellator.GLUface t) {
+ f.trail = t;
+ f.marked = true;
+ return f;
+ }
+
+ private static void FreeTrail(com.sun.opengl.impl.tessellator.GLUface t) {
+ if (true) {
+ while (t != null) {
+ t.marked = false;
+ t = t.trail;
+ }
+ } else {
+ /* absorb trailing semicolon */
+ }
+ }
+
+ static FaceCount MaximumFan(com.sun.opengl.impl.tessellator.GLUhalfEdge eOrig) {
+ /* eOrig.Lface is the face we want to render. We want to find the size
+ * of a maximal fan around eOrig.Org. To do this we just walk around
+ * the origin vertex as far as possible in both directions.
+ */
+ FaceCount newFace = new FaceCount(0, null, renderFan);
+ com.sun.opengl.impl.tessellator.GLUface trail = null;
+ com.sun.opengl.impl.tessellator.GLUhalfEdge e;
+
+ for (e = eOrig; !Marked(e.Lface); e = e.Onext) {
+ trail = AddToTrail(e.Lface, trail);
+ ++newFace.size;
+ }
+ for (e = eOrig; !Marked(e.Sym.Lface); e = e.Sym.Lnext) {
+ trail = AddToTrail(e.Sym.Lface, trail);
+ ++newFace.size;
+ }
+ newFace.eStart = e;
+ /*LINTED*/
+ FreeTrail(trail);
+ return newFace;
+ }
+
+
+ private static boolean IsEven(long n) {
+ return (n & 0x1L) == 0;
+ }
+
+ static FaceCount MaximumStrip(com.sun.opengl.impl.tessellator.GLUhalfEdge eOrig) {
+ /* Here we are looking for a maximal strip that contains the vertices
+ * eOrig.Org, eOrig.Dst, eOrig.Lnext.Dst (in that order or the
+ * reverse, such that all triangles are oriented CCW).
+ *
+ * Again we walk forward and backward as far as possible. However for
+ * strips there is a twist: to get CCW orientations, there must be
+ * an *even* number of triangles in the strip on one side of eOrig.
+ * We walk the strip starting on a side with an even number of triangles;
+ * if both side have an odd number, we are forced to shorten one side.
+ */
+ FaceCount newFace = new FaceCount(0, null, renderStrip);
+ long headSize = 0, tailSize = 0;
+ com.sun.opengl.impl.tessellator.GLUface trail = null;
+ com.sun.opengl.impl.tessellator.GLUhalfEdge e, eTail, eHead;
+
+ for (e = eOrig; !Marked(e.Lface); ++tailSize, e = e.Onext) {
+ trail = AddToTrail(e.Lface, trail);
+ ++tailSize;
+ e = e.Lnext.Sym;
+ if (Marked(e.Lface)) break;
+ trail = AddToTrail(e.Lface, trail);
+ }
+ eTail = e;
+
+ for (e = eOrig; !Marked(e.Sym.Lface); ++headSize, e = e.Sym.Onext.Sym) {
+ trail = AddToTrail(e.Sym.Lface, trail);
+ ++headSize;
+ e = e.Sym.Lnext;
+ if (Marked(e.Sym.Lface)) break;
+ trail = AddToTrail(e.Sym.Lface, trail);
+ }
+ eHead = e;
+
+ newFace.size = tailSize + headSize;
+ if (IsEven(tailSize)) {
+ newFace.eStart = eTail.Sym;
+ } else if (IsEven(headSize)) {
+ newFace.eStart = eHead;
+ } else {
+ /* Both sides have odd length, we must shorten one of them. In fact,
+ * we must start from eHead to guarantee inclusion of eOrig.Lface.
+ */
+ --newFace.size;
+ newFace.eStart = eHead.Onext;
+ }
+ /*LINTED*/
+ FreeTrail(trail);
+ return newFace;
+ }
+
+ private static class RenderTriangle implements renderCallBack {
+ public void render(GLUtessellatorImpl tess, com.sun.opengl.impl.tessellator.GLUhalfEdge e, long size) {
+ /* Just add the triangle to a triangle list, so we can render all
+ * the separate triangles at once.
+ */
+ assert (size == 1);
+ tess.lonelyTriList = AddToTrail(e.Lface, tess.lonelyTriList);
+ }
+ }
+
+
+ static void RenderLonelyTriangles(GLUtessellatorImpl tess, com.sun.opengl.impl.tessellator.GLUface f) {
+ /* Now we render all the separate triangles which could not be
+ * grouped into a triangle fan or strip.
+ */
+ com.sun.opengl.impl.tessellator.GLUhalfEdge e;
+ int newState;
+ int edgeState = -1; /* force edge state output for first vertex */
+
+ tess.callBeginOrBeginData(GL.GL_TRIANGLES);
+
+ for (; f != null; f = f.trail) {
+ /* Loop once for each edge (there will always be 3 edges) */
+
+ e = f.anEdge;
+ do {
+ if (tess.flagBoundary) {
+ /* Set the "edge state" to true just before we output the
+ * first vertex of each edge on the polygon boundary.
+ */
+ newState = (!e.Sym.Lface.inside) ? 1 : 0;
+ if (edgeState != newState) {
+ edgeState = newState;
+ tess.callEdgeFlagOrEdgeFlagData( edgeState != 0);
+ }
+ }
+ tess.callVertexOrVertexData( e.Org.data);
+
+ e = e.Lnext;
+ } while (e != f.anEdge);
+ }
+ tess.callEndOrEndData();
+ }
+
+ private static class RenderFan implements renderCallBack {
+ public void render(GLUtessellatorImpl tess, com.sun.opengl.impl.tessellator.GLUhalfEdge e, long size) {
+ /* Render as many CCW triangles as possible in a fan starting from
+ * edge "e". The fan *should* contain exactly "size" triangles
+ * (otherwise we've goofed up somewhere).
+ */
+ tess.callBeginOrBeginData( GL.GL_TRIANGLE_FAN);
+ tess.callVertexOrVertexData( e.Org.data);
+ tess.callVertexOrVertexData( e.Sym.Org.data);
+
+ while (!Marked(e.Lface)) {
+ e.Lface.marked = true;
+ --size;
+ e = e.Onext;
+ tess.callVertexOrVertexData( e.Sym.Org.data);
+ }
+
+ assert (size == 0);
+ tess.callEndOrEndData();
+ }
+ }
+
+ private static class RenderStrip implements renderCallBack {
+ public void render(GLUtessellatorImpl tess, com.sun.opengl.impl.tessellator.GLUhalfEdge e, long size) {
+ /* Render as many CCW triangles as possible in a strip starting from
+ * edge "e". The strip *should* contain exactly "size" triangles
+ * (otherwise we've goofed up somewhere).
+ */
+ tess.callBeginOrBeginData( GL.GL_TRIANGLE_STRIP);
+ tess.callVertexOrVertexData( e.Org.data);
+ tess.callVertexOrVertexData( e.Sym.Org.data);
+
+ while (!Marked(e.Lface)) {
+ e.Lface.marked = true;
+ --size;
+ e = e.Lnext.Sym;
+ tess.callVertexOrVertexData( e.Org.data);
+ if (Marked(e.Lface)) break;
+
+ e.Lface.marked = true;
+ --size;
+ e = e.Onext;
+ tess.callVertexOrVertexData( e.Sym.Org.data);
+ }
+
+ assert (size == 0);
+ tess.callEndOrEndData();
+ }
+ }
+
+ /************************ Boundary contour decomposition ******************/
+
+/* __gl_renderBoundary( tess, mesh ) takes a mesh, and outputs one
+ * contour for each face marked "inside". The rendering output is
+ * provided as callbacks (see the api).
+ */
+ public static void __gl_renderBoundary(GLUtessellatorImpl tess, com.sun.opengl.impl.tessellator.GLUmesh mesh) {
+ com.sun.opengl.impl.tessellator.GLUface f;
+ com.sun.opengl.impl.tessellator.GLUhalfEdge e;
+
+ for (f = mesh.fHead.next; f != mesh.fHead; f = f.next) {
+ if (f.inside) {
+ tess.callBeginOrBeginData( GL.GL_LINE_LOOP);
+ e = f.anEdge;
+ do {
+ tess.callVertexOrVertexData( e.Org.data);
+ e = e.Lnext;
+ } while (e != f.anEdge);
+ tess.callEndOrEndData();
+ }
+ }
+ }
+
+
+ /************************ Quick-and-dirty decomposition ******************/
+
+ private static final int SIGN_INCONSISTENT = 2;
+
+ static int ComputeNormal(GLUtessellatorImpl tess, double[] norm, boolean check)
+/*
+ * If check==false, we compute the polygon normal and place it in norm[].
+ * If check==true, we check that each triangle in the fan from v0 has a
+ * consistent orientation with respect to norm[]. If triangles are
+ * consistently oriented CCW, return 1; if CW, return -1; if all triangles
+ * are degenerate return 0; otherwise (no consistent orientation) return
+ * SIGN_INCONSISTENT.
+ */ {
+ com.sun.opengl.impl.tessellator.CachedVertex[] v = tess.cache;
+// CachedVertex vn = v0 + tess.cacheCount;
+ int vn = tess.cacheCount;
+// CachedVertex vc;
+ int vc;
+ double dot, xc, yc, zc, xp, yp, zp;
+ double[] n = new double[3];
+ int sign = 0;
+
+ /* Find the polygon normal. It is important to get a reasonable
+ * normal even when the polygon is self-intersecting (eg. a bowtie).
+ * Otherwise, the computed normal could be very tiny, but perpendicular
+ * to the true plane of the polygon due to numerical noise. Then all
+ * the triangles would appear to be degenerate and we would incorrectly
+ * decompose the polygon as a fan (or simply not render it at all).
+ *
+ * We use a sum-of-triangles normal algorithm rather than the more
+ * efficient sum-of-trapezoids method (used in CheckOrientation()
+ * in normal.c). This lets us explicitly reverse the signed area
+ * of some triangles to get a reasonable normal in the self-intersecting
+ * case.
+ */
+ if (!check) {
+ norm[0] = norm[1] = norm[2] = 0.0;
+ }
+
+ vc = 1;
+ xc = v[vc].coords[0] - v[0].coords[0];
+ yc = v[vc].coords[1] - v[0].coords[1];
+ zc = v[vc].coords[2] - v[0].coords[2];
+ while (++vc < vn) {
+ xp = xc;
+ yp = yc;
+ zp = zc;
+ xc = v[vc].coords[0] - v[0].coords[0];
+ yc = v[vc].coords[1] - v[0].coords[1];
+ zc = v[vc].coords[2] - v[0].coords[2];
+
+ /* Compute (vp - v0) cross (vc - v0) */
+ n[0] = yp * zc - zp * yc;
+ n[1] = zp * xc - xp * zc;
+ n[2] = xp * yc - yp * xc;
+
+ dot = n[0] * norm[0] + n[1] * norm[1] + n[2] * norm[2];
+ if (!check) {
+ /* Reverse the contribution of back-facing triangles to get
+ * a reasonable normal for self-intersecting polygons (see above)
+ */
+ if (dot >= 0) {
+ norm[0] += n[0];
+ norm[1] += n[1];
+ norm[2] += n[2];
+ } else {
+ norm[0] -= n[0];
+ norm[1] -= n[1];
+ norm[2] -= n[2];
+ }
+ } else if (dot != 0) {
+ /* Check the new orientation for consistency with previous triangles */
+ if (dot > 0) {
+ if (sign < 0) return SIGN_INCONSISTENT;
+ sign = 1;
+ } else {
+ if (sign > 0) return SIGN_INCONSISTENT;
+ sign = -1;
+ }
+ }
+ }
+ return sign;
+ }
+
+/* __gl_renderCache( tess ) takes a single contour and tries to render it
+ * as a triangle fan. This handles convex polygons, as well as some
+ * non-convex polygons if we get lucky.
+ *
+ * Returns true if the polygon was successfully rendered. The rendering
+ * output is provided as callbacks (see the api).
+ */
+ public static boolean __gl_renderCache(GLUtessellatorImpl tess) {
+ com.sun.opengl.impl.tessellator.CachedVertex[] v = tess.cache;
+// CachedVertex vn = v0 + tess.cacheCount;
+ int vn = tess.cacheCount;
+// CachedVertex vc;
+ int vc;
+ double[] norm = new double[3];
+ int sign;
+
+ if (tess.cacheCount < 3) {
+ /* Degenerate contour -- no output */
+ return true;
+ }
+
+ norm[0] = tess.normal[0];
+ norm[1] = tess.normal[1];
+ norm[2] = tess.normal[2];
+ if (norm[0] == 0 && norm[1] == 0 && norm[2] == 0) {
+ ComputeNormal( tess, norm, false);
+ }
+
+ sign = ComputeNormal( tess, norm, true);
+ if (sign == SIGN_INCONSISTENT) {
+ /* Fan triangles did not have a consistent orientation */
+ return false;
+ }
+ if (sign == 0) {
+ /* All triangles were degenerate */
+ return true;
+ }
+
+ if ( !USE_OPTIMIZED_CODE_PATH ) {
+ return false;
+ } else {
+ /* Make sure we do the right thing for each winding rule */
+ switch (tess.windingRule) {
+ case GLU.GLU_TESS_WINDING_ODD:
+ case GLU.GLU_TESS_WINDING_NONZERO:
+ break;
+ case GLU.GLU_TESS_WINDING_POSITIVE:
+ if (sign < 0) return true;
+ break;
+ case GLU.GLU_TESS_WINDING_NEGATIVE:
+ if (sign > 0) return true;
+ break;
+ case GLU.GLU_TESS_WINDING_ABS_GEQ_TWO:
+ return true;
+ }
+
+ tess.callBeginOrBeginData( tess.boundaryOnly ? GL.GL_LINE_LOOP
+ : (tess.cacheCount > 3) ? GL.GL_TRIANGLE_FAN
+ : GL.GL_TRIANGLES);
+
+ tess.callVertexOrVertexData( v[0].data);
+ if (sign > 0) {
+ for (vc = 1; vc < vn; ++vc) {
+ tess.callVertexOrVertexData( v[vc].data);
+ }
+ } else {
+ for (vc = vn - 1; vc > 0; --vc) {
+ tess.callVertexOrVertexData( v[vc].data);
+ }
+ }
+ tess.callEndOrEndData();
+ return true;
+ }
+ }
+}