diff options
author | Kenneth Russel <[email protected]> | 2005-10-24 19:21:03 +0000 |
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committer | Kenneth Russel <[email protected]> | 2005-10-24 19:21:03 +0000 |
commit | d6f9dbc493df725d3d574403549de142c5e1222a (patch) | |
tree | 8eb152b0627f8d1897a27c5204d6ce2efb4963e4 /src/classes/com/sun/opengl/impl/tessellator/Render.java | |
parent | 42843c3290d64c41c9c8a18b93f5ad3c00d35ddc (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
Diffstat (limited to 'src/classes/com/sun/opengl/impl/tessellator/Render.java')
-rw-r--r-- | src/classes/com/sun/opengl/impl/tessellator/Render.java | 547 |
1 files changed, 547 insertions, 0 deletions
diff --git a/src/classes/com/sun/opengl/impl/tessellator/Render.java b/src/classes/com/sun/opengl/impl/tessellator/Render.java new file mode 100644 index 000000000..a7a126a4c --- /dev/null +++ b/src/classes/com/sun/opengl/impl/tessellator/Render.java @@ -0,0 +1,547 @@ +/* +* 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; + } + } +} |