Add polygon triangulation, by cheating. I'm using the gl tesselator

for that, and storing the triangles instead of rendering them
immediately. Not sure if that's smart; in theory could change from
implementation to implementation, but the results look much better
than I would get myself.

[git-p4: depot-paths = "//depot/solvespace/": change = 1733]

Makefile

@@ -22,6 +22,7 @@ SSOBJS   = $(OBJDIR)\solvespace.obj \
            $(OBJDIR)\file.obj \
            $(OBJDIR)\system.obj \
            $(OBJDIR)\polygon.obj \
+           $(OBJDIR)\mesh.obj \
 
 
 LIBS = user32.lib gdi32.lib comctl32.lib advapi32.lib opengl32.lib glu32.lib

entity.cpp

@@ -527,10 +527,7 @@ void Entity::LineDrawOrGetDistance(Vector a, Vector b) {
 void Entity::LineDrawOrGetDistanceOrEdge(Vector a, Vector b) {
     LineDrawOrGetDistance(a, b);
     if(dogd.edges && !construction) {
-        SEdge edge;
+        dogd.edges->AddEdge(a, b);
-        edge.tag = 0;
-        edge.a = a; edge.b = b;
-        dogd.edges->l.Add(&edge);
     }
 }
 

glhelper.cpp

@@ -111,11 +111,24 @@ void glxColor4d(double r, double g, double b, double a)
     if(!ColorLocked) glColor4d(r, g, b, a);
 }
 
-static void __stdcall Vertex(Vector *p) {
+static void GLX_CALLBACK Vertex(Vector *p) {
     glxVertex3v(*p);
 }
-static void __stdcall Combine(double coords[3], void *vertexData[4],
+
-                                float weight[4], void **outData)
+void glxFillPolygon(SPolygon *p)
+{
+    GLUtesselator *gt = gluNewTess();
+    gluTessCallback(gt, GLU_TESS_BEGIN, (glxCallbackFptr *)glBegin);
+    gluTessCallback(gt, GLU_TESS_END, (glxCallbackFptr *)glEnd);
+    gluTessCallback(gt, GLU_TESS_VERTEX, (glxCallbackFptr *)Vertex);
+
+    glxTesselatePolygon(gt, p);
+
+    gluDeleteTess(gt);
+}
+
+static void GLX_CALLBACK Combine(double coords[3], void *vertexData[4],
+                                 float weight[4], void **outData)
 {
     Vector *n = (Vector *)AllocTemporary(sizeof(Vector));
     n->x = coords[0];
@@ -124,16 +137,11 @@ static void __stdcall Combine(double coords[3], void *vertexData[4],
 
     *outData = n;
 }
-void glxFillPolygon(SPolygon *p)
+void glxTesselatePolygon(GLUtesselator *gt, SPolygon *p)
 {
     int i, j;
 
-    GLUtesselator *gt = gluNewTess();
+    gluTessCallback(gt, GLU_TESS_COMBINE, (glxCallbackFptr *)Combine);
-    typedef void __stdcall cf(void);
-    gluTessCallback(gt, GLU_TESS_BEGIN, (cf *)glBegin);
-    gluTessCallback(gt, GLU_TESS_END, (cf *)glEnd);
-    gluTessCallback(gt, GLU_TESS_VERTEX, (cf *)Vertex);
-    gluTessCallback(gt, GLU_TESS_COMBINE, (cf *)Combine);
     gluTessProperty(gt, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_ODD);
 
     Vector normal = p->normal;
@@ -155,7 +163,6 @@ void glxFillPolygon(SPolygon *p)
         gluTessEndContour(gt);
     }
     gluTessEndPolygon(gt);
-    gluDeleteTess(gt);
 }
 
 void glxDebugPolygon(SPolygon *p)
@@ -196,7 +203,7 @@ void glxDebugEdgeList(SEdgeList *el)
         if(se->tag) continue;
         Vector a = se->a, b = se->b;
 
-        glxLockColorTo(0, 1, 0);
+        glxLockColorTo(0, 1, 1);
         Vector d = (a.Minus(b)).WithMagnitude(-0);
         glBegin(GL_LINES);
             glxVertex3v(a.Plus(d));
@@ -210,6 +217,32 @@ void glxDebugEdgeList(SEdgeList *el)
     }
 }
 
+void glxDebugMesh(SMesh *m)
+{
+    int i;
+    glLineWidth(2);
+    glPointSize(7);
+    glDisable(GL_DEPTH_TEST);
+    glxUnlockColor();
+    for(i = 0; i < m->l.n; i++) {
+        STriangle *t = &(m->l.elem[i]);
+        if(t->tag) continue;
+
+        glxColor4d(0, 1, 0, 0.3);
+        glBegin(GL_LINE_LOOP);
+            glxVertex3v(t->a);
+            glxVertex3v(t->b);
+            glxVertex3v(t->c);
+        glEnd();
+        glxColor4d(0, 0, 1, 0.4);
+        glBegin(GL_POINTS);
+            glxVertex3v(t->a);
+            glxVertex3v(t->b);
+            glxVertex3v(t->c);
+        glEnd();
+    }
+}
+
 void glxMarkPolygonNormal(SPolygon *p)
 {
     Vector tail = Vector::MakeFrom(0, 0, 0);

graphicswin.cpp

@@ -1181,10 +1181,11 @@ void GraphicsWindow::Paint(int w, int h) {
         selection[i].Draw();
     }
 
-    if(SS.group.n >= 5) {
+    if(SS.group.n >= 2) {
-        if(1) {
+        SMesh m; ZERO(&m);
-            //XXX
+        (SS.group.elem[1].poly).TriangulateInto(&m);
-        }
+        glxDebugMesh(&m);
+        m.Clear();
     }
 }
 

polygon.cpp

@@ -1,5 +1,16 @@
 #include "solvespace.h"
 
+void SEdgeList::Clear(void) {
+    l.Clear();
+}
+
+void SEdgeList::AddEdge(Vector a, Vector b) {
+    SEdge e; ZERO(&e);
+    e.a = a;
+    e.b = b;
+    l.Add(&e);
+}
+
 bool SEdgeList::AssemblePolygon(SPolygon *dest, SEdge *errorAt) {
     dest->Clear();
 
@@ -52,79 +63,6 @@ bool SEdgeList::AssemblePolygon(SPolygon *dest, SEdge *errorAt) {
     }
 }
 
-void SPolygon::Clear(void) {
-    int i;
-    for(i = 0; i < l.n; i++) {
-        (l.elem[i]).l.Clear();
-    }
-    l.Clear();
-}
-
-void SPolygon::AddEmptyContour(void) {
-    SContour c;
-    memset(&c, 0, sizeof(c));
-    l.Add(&c);
-}
-
-void SPolygon::AddPoint(Vector p) {
-    if(l.n < 1) oops();
-
-    SPoint sp;
-    sp.tag = 0;
-    sp.p = p;
-
-    // Add to the last contour in the list
-    (l.elem[l.n-1]).l.Add(&sp);
-}
-
-void SPolygon::MakeEdgesInto(SEdgeList *el) {
-    int i;
-    for(i = 0; i < l.n; i++) {
-        (l.elem[i]).MakeEdgesInto(el);
-    }
-}
-
-Vector SPolygon::ComputeNormal(void) {
-    if(l.n < 1) return Vector::MakeFrom(0, 0, 0);
-    return (l.elem[0]).ComputeNormal();
-}
-
-bool SPolygon::ContainsPoint(Vector p) {
-    bool inside = false;
-    int i;
-    for(i = 0; i < l.n; i++) {
-        SContour *sc = &(l.elem[i]);
-        if(sc->ContainsPointProjdToNormal(normal, p)) {
-            inside = !inside;
-        }
-    }
-    return inside;
-}
-
-void SPolygon::FixContourDirections(void) {
-    // Outside curve looks counterclockwise, projected against our normal.
-    int i, j;
-    for(i = 0; i < l.n; i++) {
-        SContour *sc = &(l.elem[i]);
-        if(sc->l.n < 1) continue;
-        Vector pt = (sc->l.elem[0]).p;
-
-        bool outer = true;
-        for(j = 0; j < l.n; j++) {
-            if(i == j) continue;
-            SContour *sct = &(l.elem[j]);
-            if(sct->ContainsPointProjdToNormal(normal, pt)) {
-                outer = !outer;
-            }
-        }
-   
-        bool clockwise = sc->IsClockwiseProjdToNormal(normal);
-        if(clockwise && outer || (!clockwise && !outer)) {
-            sc->Reverse();
-        }
-    }
-}
-
 void SContour::MakeEdgesInto(SEdgeList *el) {
     int i;
     for(i = 0; i < (l.n-1); i++) {
@@ -208,3 +146,124 @@ void SContour::Reverse(void) {
     }
 }
 
+
+void SPolygon::Clear(void) {
+    int i;
+    for(i = 0; i < l.n; i++) {
+        (l.elem[i]).l.Clear();
+    }
+    l.Clear();
+}
+
+void SPolygon::AddEmptyContour(void) {
+    SContour c;
+    memset(&c, 0, sizeof(c));
+    l.Add(&c);
+}
+
+void SPolygon::AddPoint(Vector p) {
+    if(l.n < 1) oops();
+
+    SPoint sp;
+    sp.tag = 0;
+    sp.p = p;
+
+    // Add to the last contour in the list
+    (l.elem[l.n-1]).l.Add(&sp);
+}
+
+void SPolygon::MakeEdgesInto(SEdgeList *el) {
+    int i;
+    for(i = 0; i < l.n; i++) {
+        (l.elem[i]).MakeEdgesInto(el);
+    }
+}
+
+Vector SPolygon::ComputeNormal(void) {
+    if(l.n < 1) return Vector::MakeFrom(0, 0, 0);
+    return (l.elem[0]).ComputeNormal();
+}
+
+bool SPolygon::ContainsPoint(Vector p) {
+    bool inside = false;
+    int i;
+    for(i = 0; i < l.n; i++) {
+        SContour *sc = &(l.elem[i]);
+        if(sc->ContainsPointProjdToNormal(normal, p)) {
+            inside = !inside;
+        }
+    }
+    return inside;
+}
+
+void SPolygon::FixContourDirections(void) {
+    // Outside curve looks counterclockwise, projected against our normal.
+    int i, j;
+    for(i = 0; i < l.n; i++) {
+        SContour *sc = &(l.elem[i]);
+        if(sc->l.n < 1) continue;
+        Vector pt = (sc->l.elem[0]).p;
+
+        bool outer = true;
+        for(j = 0; j < l.n; j++) {
+            if(i == j) continue;
+            SContour *sct = &(l.elem[j]);
+            if(sct->ContainsPointProjdToNormal(normal, pt)) {
+                outer = !outer;
+            }
+        }
+   
+        bool clockwise = sc->IsClockwiseProjdToNormal(normal);
+        if(clockwise && outer || (!clockwise && !outer)) {
+            sc->Reverse();
+        }
+    }
+}
+
+static int TriMode, TriVertexCount;
+static Vector Tri1, TriNMinus1, TriNMinus2;
+static SMesh *TriMesh;
+static void GLX_CALLBACK TriBegin(int mode) 
+{
+    TriMode = mode;
+    TriVertexCount = 0;
+}
+static void GLX_CALLBACK TriEnd(void)
+{
+}
+static void GLX_CALLBACK TriVertex(Vector *triN)
+{
+    if(TriVertexCount == 0) {
+        Tri1 = *triN;
+    }
+    if(TriMode == GL_TRIANGLES) {
+        if((TriVertexCount % 3) == 2) {
+            TriMesh->AddTriangle(TriNMinus2, TriNMinus1, *triN);
+        }
+    } else if(TriMode == GL_TRIANGLE_FAN) {
+        if(TriVertexCount >= 2) {
+            TriMesh->AddTriangle(Tri1, TriNMinus1, *triN);
+        }
+    } else if(TriMode == GL_TRIANGLE_STRIP) {
+        if(TriVertexCount >= 2) {
+            TriMesh->AddTriangle(TriNMinus2, TriNMinus1, *triN);
+        }
+    } else oops();
+            
+    TriNMinus2 = TriNMinus1;
+    TriNMinus1 = *triN;
+    TriVertexCount++;
+}
+void SPolygon::TriangulateInto(SMesh *m) {
+    TriMesh = m;
+
+    GLUtesselator *gt = gluNewTess();
+    gluTessCallback(gt, GLU_TESS_BEGIN, (glxCallbackFptr *)TriBegin);
+    gluTessCallback(gt, GLU_TESS_END, (glxCallbackFptr *)TriEnd);
+    gluTessCallback(gt, GLU_TESS_VERTEX, (glxCallbackFptr *)TriVertex);
+
+    glxTesselatePolygon(gt, this);
+
+    gluDeleteTess(gt);
+}
+

polygon.h

@@ -3,6 +3,7 @@
 #define __POLYGON_H
 
 class SPolygon;
+class SMesh;
 
 template <class T>
 class SList {
@@ -43,12 +44,9 @@ class SEdgeList {
 public:
     SList<SEdge>    l;
 
+    void Clear(void);
+    void AddEdge(Vector a, Vector b);
     bool AssemblePolygon(SPolygon *dest, SEdge *errorAt);
-    void CopyBreaking(SEdgeList *dest);
-    static const int UNION = 0, DIFF = 1, INTERSECT = 2;
-    bool BooleanOp(int op, bool inA, bool inB);
-    void CullForBoolean(int op, SPolygon *a, SPolygon *b);
-    void CullDuplicates(void);
 };
 
 class SPoint {
@@ -66,8 +64,6 @@ public:
     Vector ComputeNormal(void);
     bool IsClockwiseProjdToNormal(Vector n);
     bool ContainsPointProjdToNormal(Vector n, Vector p);
-    void IntersectAgainstPlane(double *inter, int *inters,
-                               Vector u, Vector v, double vp);
 };
 
 class SPolygon {
@@ -81,20 +77,24 @@ public:
     bool ContainsPoint(Vector p);
     void MakeEdgesInto(SEdgeList *el);
     void FixContourDirections(void);
+    void TriangulateInto(SMesh *m);
     void Clear(void);
 };
 
 class STriangle {
 public:
-    Vector a, b, c;
+    int     tag;
+    Vector  a, b, c;
 };
 
 class SBsp2 {
+public:
     SEdge       edge;
-};
 
-class SBsp1d {
+    SBsp2       *pos;
-    SEdge       edge;
+    SBsp2       *neg;
+
+    SBsp2       *more;
 };
 
 class SBsp3 {
@@ -112,6 +112,9 @@ public:
 class SMesh {
 public:
     SList<STriangle>    l;
+
+    void Clear(void);
+    void AddTriangle(Vector a, Vector b, Vector c);
 };
 
 #endif

sketch.cpp

@@ -418,7 +418,7 @@ void Group::MakePolygons(void) {
         }
 
         // Get the source polygon to extrude, and break it down to edges
-        edges.l.Clear();
+        edges.Clear();
         Group *src = SS.GetGroup(opA);
 
         (src->poly).MakeEdgesInto(&edges);
@@ -440,7 +440,7 @@ void Group::MakePolygons(void) {
         np.FixContourDirections();
 
         // Regenerate the edges, with the contour directions fixed up.
-        edges.l.Clear();
+        edges.Clear();
         np.MakeEdgesInto(&edges);
 
         // The sides
@@ -465,7 +465,7 @@ void Group::MakePolygons(void) {
         if(!edges.AssemblePolygon(&np, NULL)) oops();
         np.normal = n.ScaledBy(-1);
     }
-    edges.l.Clear();
+    edges.Clear();
 }
 
 void Group::Draw(void) {

solvespace.h

@@ -14,6 +14,9 @@
 
 #define SWAP(T, a, b) do { T temp = (a); (a) = (b); (b) = temp; } while(0)
 #define ZERO(v) memset((v), 0, sizeof(*(v)))
+#define CO(v) (v).x, (v).y, (v).z
+
+#define LENGTH_EPS  (0.0001)
 
 #define isforname(c) (isalnum(c) || (c) == '_' || (c) == '-' || (c) == '#')
 
@@ -70,9 +73,13 @@ void vl(void); // debug function to validate
 
 // Utility functions that are provided in the platform-independent code.
 void glxVertex3v(Vector u);
+#define GLX_CALLBACK __stdcall
+typedef void GLX_CALLBACK glxCallbackFptr(void);
+void glxTesselatePolygon(GLUtesselator *gt, SPolygon *p);
 void glxFillPolygon(SPolygon *p);
 void glxDebugPolygon(SPolygon *p);
 void glxDebugEdgeList(SEdgeList *l);
+void glxDebugMesh(SMesh *m);
 void glxMarkPolygonNormal(SPolygon *p);
 void glxWriteText(char *str);
 void glxWriteTextRefCenter(char *str);

util.cpp

@@ -178,10 +178,9 @@ Vector Vector::MakeFrom(double x, double y, double z) {
 }
 
 bool Vector::Equals(Vector v) {
-    double tol = 0.00001;
+    if(fabs(x - v.x) > LENGTH_EPS) return false;
-    if(fabs(x - v.x) > tol) return false;
+    if(fabs(y - v.y) > LENGTH_EPS) return false;
-    if(fabs(y - v.y) > tol) return false;
+    if(fabs(z - v.z) > LENGTH_EPS) return false;
-    if(fabs(z - v.z) > tol) return false;
     return true;
 }