[Gzz-commits] gzz/gfx/librenderables renderables.py

[Janne V. Kujala]

CVSROOT:        /cvsroot/gzz
Module name:    gzz
Changes by:     Janne V. Kujala <address@hidden>        02/11/04 10:47:07

Modified files:
        gfx/librenderables: renderables.py 

Log message:
        Compute texture q coordinates in IrregularEllipse

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/gfx/librenderables/renderables.py.diff?tr1=1.129&tr2=1.130&r1=text&r2=text

Patches:
Index: gzz/gfx/librenderables/renderables.py
diff -u gzz/gfx/librenderables/renderables.py:1.129 
gzz/gfx/librenderables/renderables.py:1.130
--- gzz/gfx/librenderables/renderables.py:1.129 Mon Nov  4 05:45:03 2002
+++ gzz/gfx/librenderables/renderables.py       Mon Nov  4 10:47:07 2002
@@ -1144,12 +1144,40 @@
         int n = (int)(36 * dicefactor);
         std::vector<ZPt> vert(n+1);
         std::vector<ZVec> norm(n+1);
+        std::vector<float> texq(n+1);
 
         for (int i = 0; i <= n; i++) { 
             float a = i * 2*M_PI / n;
             vert[i] = coords2.transform(ZPt(cos(a), sin(a), 0));
         }
 
+        for (int i = 0; i <= n; i++) {
+            norm[i] = (vert[(i+1) % n] - vert[(i+n-1) % n]).cw90().normalize()
+                    * (0.5 * ripple_scale * texscale);
+        }
+
+        // Compute outer edge / inner edge length ratio
+        // for segments before and after a point and use the
+        // geometric average as the q component of the point.
+        // Exact mapping of the texture to the segment
+        // would require repeating the vertices.
+        for (int i = 0; i <= n; i++) {
+            ZPt p0 = vert[(i+n-1) % n];
+            ZPt p1 = vert[i];
+            ZPt p2 = vert[(i+1) % n];
+            ZVec n0 = norm[(i+n-1) % n];
+            ZVec n1 = norm[i];
+            ZVec n2 = norm[(i+1) % n];
+
+            float q0 = ((p0 + n0) - (p1 + n1)).length() /
+                       ((p0 - n0) - (p1 - n1)).length();
+
+            float q1 = ((p1 + n1) - (p2 + n2)).length() /
+                       ((p1 - n1) - (p2 - n2)).length();
+
+            texq[i] = sqrt(q0 * q1);
+        }
+
         int angles = 3;
 
         setup();
@@ -1157,12 +1185,11 @@
         glBegin(GL_QUAD_STRIP);
         for (int i = 0; i <= n; i++) {
             ZPt p = vert[i];
-            ZVec norm = (vert[(i+1) % n] - vert[(i+n-1) % 
n]).cw90().normalize();
-            norm *= 0.5 * ripple_scale * texscale;
-
+            ZVec normal = norm[i];
+            float q = texq[i];
 
             float dotvec[4] = {0,0,0,0};
-            float angle = atan2(-norm.x, norm.y); // angle(norm.cw90())
+            float angle = atan2(-normal.x, normal.y); // angle(normal.cw90())
 
             float a = (angle + M_PI) * angles * (1 / M_PI);
             int ind = (int)a;
@@ -1176,13 +1203,12 @@
             else
                 glColor4f(0, 0, 0, 1);
         
-            // XXX: need to compute multiplier according to
-            //      quad inside/outside length difference
             glTexCoord4f(p.x, p.y, p.z, texscale);
             glSecondaryColor3fEXT(1,1,1);
-            coords1.vertex(p - norm);
+            coords1.vertex(p - normal);
+            glTexCoord4f(q * p.x, q * p.y, q * p.z, q * texscale);
             glSecondaryColor3fEXT(0,0,0);
-            coords1.vertex(p + norm);
+            coords1.vertex(p + normal);
         }
         glEnd();
 
@@ -1194,10 +1220,7 @@
         glBegin(GL_TRIANGLE_FAN);
         coords1.vertex(coords2.transform(ZPt(0,0,0)));
         for (int i = 0; i <= n; i++) {
-            ZPt p = vert[i];
-            ZVec norm = (vert[(i+1) % n] - vert[(i+n-1) % 
n]).cw90().normalize();
-            norm *= 0.5 * ripple_scale * texscale;
-            coords1.vertex(p - norm);
+            coords1.vertex(vert[i] - norm[i]);
         }
         glEnd();