Add a unit test for drawing complex shapes (#565)

4 files changed, 28 insertions, 6 deletions

diff --git a/src/Fl_Graphics_Driver.cxx b/src/Fl_Graphics_Driver.cxx
index 967b0159b..35697c256 100644
--- a/src/Fl_Graphics_Driver.cxx
+++ b/src/Fl_Graphics_Driver.cxx
@@ -55,6 +55,7 @@ Fl_Graphics_Driver::Fl_Graphics_Driver()
   p_size = 0;
   xpoint = NULL;
   what = NONE;
+  n = 0;
 };
 
 /** Destructor */
diff --git a/src/drivers/OpenGL/Fl_OpenGL_Graphics_Driver_vertex.cxx b/src/drivers/OpenGL/Fl_OpenGL_Graphics_Driver_vertex.cxx
index 7cd144ce6..b5ec90bf4 100644
--- a/src/drivers/OpenGL/Fl_OpenGL_Graphics_Driver_vertex.cxx
+++ b/src/drivers/OpenGL/Fl_OpenGL_Graphics_Driver_vertex.cxx
@@ -41,6 +41,7 @@
 // double Fl_OpenGL_Graphics_Driver::transform_dy(double x, double y)
 
 void Fl_OpenGL_Graphics_Driver::begin_points() {
+  Fl_Graphics_Driver::begin_points();
   glBegin(GL_POINTS);
 }
 
@@ -49,6 +50,7 @@ void Fl_OpenGL_Graphics_Driver::end_points() {
 }
 
 void Fl_OpenGL_Graphics_Driver::begin_line() {
+  Fl_Graphics_Driver::begin_line();
   glBegin(GL_LINE_STRIP);
 }
 
@@ -57,6 +59,7 @@ void Fl_OpenGL_Graphics_Driver::end_line() {
 }
 
 void Fl_OpenGL_Graphics_Driver::begin_loop() {
+  Fl_Graphics_Driver::begin_loop();
   glBegin(GL_LINE_LOOP);
 }
 
@@ -65,6 +68,7 @@ void Fl_OpenGL_Graphics_Driver::end_loop() {
 }
 
 void Fl_OpenGL_Graphics_Driver::begin_polygon() {
+  Fl_Graphics_Driver::begin_polygon();
   glBegin(GL_POLYGON);
 }
 
@@ -73,6 +77,7 @@ void Fl_OpenGL_Graphics_Driver::end_polygon() {
 }
 
 void Fl_OpenGL_Graphics_Driver::begin_complex_polygon() {
+  Fl_Graphics_Driver::begin_complex_polygon();
   glBegin(GL_POLYGON);
 }
 
diff --git a/src/fl_curve.cxx b/src/fl_curve.cxx
index 58cb2767a..c3324f96e 100644
--- a/src/fl_curve.cxx
+++ b/src/fl_curve.cxx
@@ -46,21 +46,22 @@ void Fl_Graphics_Driver::curve(double X0, double Y0,
   fl_transformed_vertex(x,y);
 
   double x1 = fl_transform_x(X1,Y1);
-  double yy1 = fl_transform_y(X1,Y1);
+  double y1 = fl_transform_y(X1,Y1);
   double x2 = fl_transform_x(X2,Y2);
   double y2 = fl_transform_y(X2,Y2);
   double x3 = fl_transform_x(X3,Y3);
   double y3 = fl_transform_y(X3,Y3);
 
   // find the area:
-  double a = fabs((x-x2)*(y3-yy1)-(y-y2)*(x3-x1));
-  double b = fabs((x-x3)*(y2-yy1)-(y-y3)*(x2-x1));
+  double a = fabs((x-x2)*(y3-y1)-(y-y2)*(x3-x1));
+  double b = fabs((x-x3)*(y2-y1)-(y-y3)*(x2-x1));
   if (b > a) a = b;
 
   // use that to guess at the number of segments:
   int nSeg = int(sqrt(a)/4);
   if (nSeg > 1) {
     if (nSeg > 100) nSeg = 100; // make huge curves not hang forever
+    if (nSeg < 9) nSeg = 9; // make tiny curevs look bearable
 
     double e = 1.0/nSeg;
 
@@ -74,9 +75,9 @@ void Fl_Graphics_Driver::curve(double X0, double Y0,
     double dx2 = dx3 + 2*xb*e*e;
 
     // calculate the coefficients of 3rd order equation:
-    double ya = (y3-3*y2+3*yy1-y);
-    double yb = 3*(y2-2*yy1+y);
-    double yc = 3*(yy1-y);
+    double ya = (y3-3*y2+3*y1-y);
+    double yb = 3*(y2-2*y1+y);
+    double yc = 3*(y1-y);
     // calculate the forward differences:
     double dy1 = ((ya*e+yb)*e+yc)*e;
     double dy3 = 6*ya*e*e*e;
diff --git a/src/fl_vertex.cxx b/src/fl_vertex.cxx
index c17a89e23..c02e24ff8 100644
--- a/src/fl_vertex.cxx
+++ b/src/fl_vertex.cxx
@@ -57,6 +57,21 @@ void Fl_Graphics_Driver::pop_matrix() {
     m = stack[--sptr];
 }
 
+/** see fl_load_identity() */
+void Fl_Graphics_Driver::load_identity() {
+  m = m0;
+}
+
+/** see fl_load_matrix() */
+void Fl_Graphics_Driver::load_matrix(double a, double b, double c, double d, double x, double y) {
+  m.a = a;
+  m.b = b;
+  m.c = c;
+  m.d = d;
+  m.x = x;
+  m.y = y;
+}
+
 /** see fl_mult_matrix() */
 void Fl_Graphics_Driver::mult_matrix(double a, double b, double c, double d, double x, double y) {
   matrix o;