Fixed orientation of polygons produced by CutTriangle2D so that we can use a TWO_SIDE light model everywhere. This also fixes the ugly "checkboard patterns" when using custom scales on continuous maps.

9905ea58 · Christophe Geuzaine · ffb67212 · 9905ea58 · 9905ea58 · 9905ea58
Commit 9905ea58 authored 21 years ago by Christophe Geuzaine
--- a/Graphics/Draw.cpp
+++ b/Graphics/Draw.cpp
-// $Id: Draw.cpp,v 1.48 2004-03-30 18:17:06 geuzaine Exp $
+// $Id: Draw.cpp,v 1.49 2004-04-27 00:11:55 geuzaine Exp $
 //
 // Copyright (C) 1997-2004 C. Geuzaine, J.-F. Remacle
 //
@@ -45,15 +45,12 @@ void Draw3d(void)
 #endif
  }
  glPolygonOffset(1.0, 1.0);
-  for(int i = 0; i < 6; i++)
-    if(CTX.clip[i])
-      glEnable((GLenum) (GL_CLIP_PLANE0 + i));
-  glShadeModel(GL_SMOOTH);
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
  glDisable(GL_CULL_FACE);
+  for(int i = 0; i < 6; i++)
+    if(CTX.clip[i])
+      glEnable((GLenum) (GL_CLIP_PLANE0 + i));
  glPushMatrix();
  Draw_Mesh(&M);
@@ -63,9 +60,6 @@ void Draw3d(void)
 void Draw2d(void)
 {
  glDisable(GL_DEPTH_TEST);
-  glDisable(GL_LIGHTING);
-  glShadeModel(GL_FLAT);
  for(int i = 0; i < 6; i++)
    glDisable((GLenum) (GL_CLIP_PLANE0 + i));
@@ -175,6 +169,7 @@ void InitRenderModel(void)
  glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
  glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 40.);
  glLightModelf(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
+  glShadeModel(GL_SMOOTH);
  // let's add some shininess to all these automatically created materials
  specular[0] = CTX.shine;
  specular[1] = CTX.shine;

--- a/Graphics/Iso.cpp
+++ b/Graphics/Iso.cpp
-// $Id: Iso.cpp,v 1.21 2004-04-26 19:54:16 geuzaine Exp $
+// $Id: Iso.cpp,v 1.22 2004-04-27 00:11:55 geuzaine Exp $
 //
 // Copyright (C) 1997-2004 C. Geuzaine, J.-F. Remacle
 //
@@ -51,15 +51,14 @@ void CutTriangle1D(double *X, double *Y, double *Z, double *Val,
 }
-// Contour computation for triangles. FIXME: the orientation of the
+// Contour computation for triangles
-// newly created polygons is wrong.
 void CutTriangle2D(double *X, double *Y, double *Z, double *Val,
                   double V1, double V2, double *Xp2, double *Yp2,
                   double *Zp2, int *Np2, double *Vp2)
 {
  int i, io[3], j, iot, Np, Fl;
-  double Xp[5], Yp[5], Zp[5], Vp[5];
+  double Xp[10], Yp[10], Zp[10], Vp[10];
  *Np2 = 0;
@@ -170,8 +169,8 @@ void CutTriangle2D(double *X, double *Y, double *Z, double *Val,
  *Np2 = 1;
  for(i = 1; i < Np; i++) {
-    if((Xp[i] != Xp2[(*Np2) - 1]) || (Yp[i] != Yp2[(*Np2) - 1])
+    if((Xp[i] != Xp2[(*Np2) - 1]) || (Yp[i] != Yp2[(*Np2) - 1]) || 
-       || (Zp[i] != Zp2[(*Np2) - 1])) {
+       (Zp[i] != Zp2[(*Np2) - 1])) {
      Vp2[*Np2] = Vp[i];
      Xp2[*Np2] = Xp[i];
      Yp2[*Np2] = Yp[i];
@@ -180,11 +179,36 @@ void CutTriangle2D(double *X, double *Y, double *Z, double *Val,
    }
  }
-  if(Xp2[0] == Xp2[(*Np2) - 1] && Yp2[0] == Yp2[(*Np2) - 1]
+  if(Xp2[0] == Xp2[(*Np2) - 1] && Yp2[0] == Yp2[(*Np2) - 1] && 
-     && Zp2[0] == Zp2[(*Np2) - 1]) {
+     Zp2[0] == Zp2[(*Np2) - 1]) {
    (*Np2)--;
  }
+  // check and fix orientation
+  double in1[3] = { X[1]-X[0], Y[1]-Y[0], Z[1]-Z[0]};
+  double in2[3] = { X[2]-X[0], Y[2]-Y[0], Z[2]-Z[0]};
+  double inn[3];
+  prodve(in1, in2, inn);
+  double out1[3] = { Xp2[1]-Xp2[0], Yp2[1]-Yp2[0], Zp2[1]-Zp2[0]};
+  double out2[3] = { Xp2[2]-Xp2[0], Yp2[2]-Yp2[0], Zp2[2]-Zp2[0]};
+  double outn[3];
+  prodve(out1, out2, outn);
+  double res;
+  prosca(inn, outn, &res);
+  if(res < 0){
+    for(i = 0; i < *Np2; i++){
+      Vp[i] = Vp2[*Np2-i-1];
+      Xp[i] = Xp2[*Np2-i-1];
+      Yp[i] = Yp2[*Np2-i-1];
+      Zp[i] = Zp2[*Np2-i-1];
+    }
+    for(i = 0; i < *Np2; i++){
+      Vp2[i] = Vp[i];
+      Xp2[i] = Xp[i];
+      Yp2[i] = Yp[i];
+      Zp2[i] = Zp[i];
+    }
+  }
 }
 // Iso for lines
@@ -314,7 +338,7 @@ void EnhanceSimplexPolygon(Post_View * View, int nb,    // nb of points in polyg
  double gr[3];
  double n[3], xx;
  prodve(v1, v2, n);
-  //norme(n);  not necessary since GL_NORMALIZE is enabled
+  norme(n);
  gradSimplex(X, Y, Z, Val, gr);
  prosca(gr, n, &xx);

--- a/Graphics/Post.cpp
+++ b/Graphics/Post.cpp
-// $Id: Post.cpp,v 1.59 2004-04-26 19:56:45 geuzaine Exp $
+// $Id: Post.cpp,v 1.60 2004-04-27 00:11:55 geuzaine Exp $
 //
 // Copyright (C) 1997-2004 C. Geuzaine, J.-F. Remacle
 //
@@ -456,15 +456,6 @@ void Draw_Post(void)
        glLineWidth(v->LineWidth);
        gl2psLineWidth(v->LineWidth * CTX.print.eps_line_width_factor);
-        // force this
-        if(v->IntervalsType == DRAW_POST_CONTINUOUS) {
-          glShadeModel(GL_SMOOTH);
-          glLightModelf(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
-        }
-        else {  // there is a bug in CutTriangle2D!! See Iso.cpp
-          glLightModelf(GL_LIGHT_MODEL_TWO_SIDE, GL_FALSE);
-        }
        switch (v->RangeType) {
        case DRAW_POST_RANGE_DEFAULT:
          ValMin = v->Min;

--- a/Graphics/PostElement.cpp
+++ b/Graphics/PostElement.cpp
-// $Id: PostElement.cpp,v 1.27 2004-04-26 19:54:16 geuzaine Exp $
+// $Id: PostElement.cpp,v 1.28 2004-04-27 00:11:55 geuzaine Exp $
 //
 // Copyright (C) 1997-2004 C. Geuzaine, J.-F. Remacle
 //
@@ -23,12 +23,6 @@
 //   Laurent Stainier
 //   Jean-Luc Flejou
-// OK, I understand why the Cut2D stuff does not work correctly with a
-// TWO_FACE light: the normal has too be coherent with the vertex
-// ordering of the polygon. Doing i=nb-1; i>=0; i-- works when the
-// classic order does not. So we really have to check the ordering of
-// the output of cut2d...
 #include "Gmsh.h"
 #include "GmshUI.h"
 #include "Geo.h"
@@ -424,10 +418,9 @@ void Draw_ScalarTriangle(Post_View * View, int preproNormals,
          norms[3 * i] = nn[0];
          norms[3 * i + 1] = nn[1];
          norms[3 * i + 2] = nn[2];
-          if(!View->
+          if(!View->get_normal(X[i] + Raise[0][i], Y[i] + Raise[1][i],
-             get_normal(X[i] + Raise[0][i], Y[i] + Raise[1][i],
+			       Z[i] + Raise[2][i], norms[3 * i], norms[3 * i + 1],
-                        Z[i] + Raise[2][i], norms[3 * i], norms[3 * i + 1],
+			       norms[3 * i + 2])) {
-                        norms[3 * i + 2])) {
            //don't print this (unless we fix draw_vector_triangle with displacement)
            //Msg(WARNING, "Oups, did not find smoothed normal");
          }
@@ -468,13 +461,12 @@ void Draw_ScalarTriangle(Post_View * View, int preproNormals,
  }
  else {
-    if(View->Light) glEnable(GL_LIGHTING);
-    glEnable(GL_POLYGON_OFFSET_FILL);
    if(View->IntervalsType == DRAW_POST_CONTINUOUS) {
      if(Val[0] >= ValMin && Val[0] <= ValMax &&
         Val[1] >= ValMin && Val[1] <= ValMax &&
         Val[2] >= ValMin && Val[2] <= ValMax) {
+	if(View->Light) glEnable(GL_LIGHTING);
+	glEnable(GL_POLYGON_OFFSET_FILL);
        glBegin(GL_TRIANGLES);
        PaletteContinuous(View, ValMin, ValMax, Val[0]);
        glNormal3dv(&norms[0]);
@@ -486,10 +478,14 @@ void Draw_ScalarTriangle(Post_View * View, int preproNormals,
        glNormal3dv(&norms[6]);
        glVertex3d(X[2] + Raise[0][2], Y[2] + Raise[1][2], Z[2] + Raise[2][2]);
        glEnd();
+	glDisable(GL_POLYGON_OFFSET_FILL);
+	glDisable(GL_LIGHTING);
      }
      else {
        CutTriangle2D(X, Y, Z, Val, ValMin, ValMax, Xp, Yp, Zp, &nb, value);
        if(nb >= 3) {
+	  if(View->Light) glEnable(GL_LIGHTING);
+	  glEnable(GL_POLYGON_OFFSET_FILL);
          glBegin(GL_POLYGON);
          for(int i = 0; i < nb; i++) {
            PaletteContinuous(View, ValMin, ValMax, value[i]);
@@ -498,6 +494,8 @@ void Draw_ScalarTriangle(Post_View * View, int preproNormals,
 		       Zp[i] + View->Raise[2] * value[i]);
          }
          glEnd();
+	  glDisable(GL_POLYGON_OFFSET_FILL);
+	  glDisable(GL_LIGHTING);
        }
      }
    }
@@ -510,12 +508,16 @@ void Draw_ScalarTriangle(Post_View * View, int preproNormals,
                        View->GVFI(ValMin, ValMax, View->NbIso + 1, k + 1),
                        Xp, Yp, Zp, &nb, value);
          if(nb >= 3) {
+	    if(View->Light) glEnable(GL_LIGHTING);
+	    glEnable(GL_POLYGON_OFFSET_FILL);
            glBegin(GL_POLYGON);
            for(int i = 0; i < nb; i++)
              glVertex3d(Xp[i] + View->Raise[0] * value[i],
 			 Yp[i] + View->Raise[1] * value[i], 
 			 Zp[i] + View->Raise[2] * value[i]);
            glEnd();
+	    glDisable(GL_POLYGON_OFFSET_FILL);
+	    glDisable(GL_LIGHTING);
          }
        }
        else {
@@ -531,8 +533,6 @@ void Draw_ScalarTriangle(Post_View * View, int preproNormals,
      }
    }
-    glDisable(GL_POLYGON_OFFSET_FILL);
-    glDisable(GL_LIGHTING);
  }
 }

--- a/Graphics/Scale.cpp
+++ b/Graphics/Scale.cpp
-// $Id: Scale.cpp,v 1.41 2004-04-20 19:15:14 geuzaine Exp $
+// $Id: Scale.cpp,v 1.42 2004-04-27 00:11:55 geuzaine Exp $
 //
 // Copyright (C) 1997-2004 C. Geuzaine, J.-F. Remacle
 //
@@ -68,11 +68,6 @@ void draw_scale(Post_View * v,
    glEnd();
  }
-  if(v->IntervalsType == DRAW_POST_CONTINUOUS)
-    glShadeModel(GL_SMOOTH);
-  else
-    glShadeModel(GL_FLAT);
  switch(v->RangeType){
  case DRAW_POST_RANGE_CUSTOM:
    ValMin = v->CustomMin;