text: Fix glyphs with flipped UVs not being processed correctly

This caused the cheesy-accent code to not flip the caron correctly.

panda/src/text/textGlyph.cxx

@@ -171,67 +171,64 @@ check_quad_geom() {
 
   // Check that the vertices are arranged in a square.
   GeomVertexReader vertex(vdata, InternalName::get_vertex());
+  GeomVertexReader texcoord(vdata, InternalName::get_texcoord());
   LVecBase3 v = vertex.get_data3();
   if (!IS_NEARLY_ZERO(v[1])) {
     return;
   }
+  LTexCoord uv(0);
+  if (texcoord.has_column()) {
+    uv = texcoord.get_data2();
+  }
   PN_stdfloat minx = v[0];
   PN_stdfloat maxx = v[0];
   PN_stdfloat miny = v[2];
   PN_stdfloat maxy = v[2];
+  PN_stdfloat minu = uv[0];
+  PN_stdfloat maxu = uv[0];
+  PN_stdfloat minv = uv[1];
+  PN_stdfloat maxv = uv[1];
 
-  for (int i = 0; i < 3; ++i) {
+  for (int i = 1; i < 4; ++i) {
     v = vertex.get_data3();
     if (!IS_NEARLY_ZERO(v[1])) {
       return;
     }
+    if (texcoord.has_column()) {
+      uv = texcoord.get_data2();
+    }
     if (!IS_NEARLY_EQUAL(v[0], minx) && !IS_NEARLY_EQUAL(v[0], maxx)) {
       if (!IS_NEARLY_EQUAL(minx, maxx)) {
         return;
       }
-      minx = min(v[0], minx);
-      maxx = max(v[0], maxx);
+      if (v[0] < minx) {
+        minx = v[0];
+        minu = uv[0];
+      }
+      if (v[0] > maxx) {
+        maxx = v[0];
+        maxu = uv[0];
+      }
     }
     if (!IS_NEARLY_EQUAL(v[2], miny) && !IS_NEARLY_EQUAL(v[2], maxy)) {
       if (!IS_NEARLY_EQUAL(miny, maxy)) {
         return;
       }
-      miny = min(v[2], miny);
-      maxy = max(v[2], maxy);
-    }
-  }
-
-  PN_stdfloat minu = 0;
-  PN_stdfloat maxu = 0;
-  PN_stdfloat minv = 0;
-  PN_stdfloat maxv = 0;
-
-  // Same for the texcoord data.
-  if (format->has_column(InternalName::get_texcoord())) {
-    GeomVertexReader texcoord(vdata, InternalName::get_texcoord());
-    LVecBase2 tc = texcoord.get_data2();
-    minu = tc[0];
-    maxu = tc[0];
-    minv = tc[1];
-    maxv = tc[1];
-
-    for (int i = 0; i < 3; ++i) {
-      tc = texcoord.get_data2();
-      if (!IS_NEARLY_EQUAL(tc[0], minu) && !IS_NEARLY_EQUAL(tc[0], maxu)) {
-        if (!IS_NEARLY_EQUAL(minu, maxu)) {
-          return;
-        }
-        minu = min(tc[0], minu);
-        maxu = max(tc[0], maxu);
+      if (v[2] < miny) {
+        miny = v[2];
+        minv = uv[1];
       }
-      if (!IS_NEARLY_EQUAL(tc[1], minv) && !IS_NEARLY_EQUAL(tc[1], maxv)) {
-        if (!IS_NEARLY_EQUAL(minv, maxv)) {
-          return;
-        }
-        minv = min(tc[1], minv);
-        maxv = max(tc[1], maxv);
+      if (v[2] > maxy) {
+        maxy = v[2];
+        maxv = uv[1];
       }
     }
+    if (!IS_NEARLY_EQUAL(uv[0], minu) && !IS_NEARLY_EQUAL(uv[0], maxu)) {
+      return;
+    }
+    if (!IS_NEARLY_EQUAL(uv[1], minv) && !IS_NEARLY_EQUAL(uv[1], maxv)) {
+      return;
+    }
   }
 
   _quad_dimensions.set(minx, miny, maxx, maxy);