1 files changed, 142 insertions, 0 deletions
diff --git a/src/drivers/OpenGL/Fl_OpenGL_Graphics_Driver_vertex.cxx b/src/drivers/OpenGL/Fl_OpenGL_Graphics_Driver_vertex.cxx
new file mode 100644
index 000000000..1dd091f0d
--- /dev/null
+++ b/src/drivers/OpenGL/Fl_OpenGL_Graphics_Driver_vertex.cxx
@@ -0,0 +1,142 @@
+//
+// "$Id$"
+//
+// Portable drawing routines for the Fast Light Tool Kit (FLTK).
+//
+// Copyright 1998-2016 by Bill Spitzak and others.
+//
+// This library is free software. Distribution and use rights are outlined in
+// the file "COPYING" which should have been included with this file.  If this
+// file is missing or damaged, see the license at:
+//
+//     http://www.fltk.org/COPYING.php
+//
+// Please report all bugs and problems on the following page:
+//
+//     http://www.fltk.org/str.php
+//
+
+#ifndef FL_CFG_GFX_OPENGL_VERTEX_CXX
+#define FL_CFG_GFX_OPENGL_VERTEX_CXX
+
+/**
+  \file opengl_vertex.cxx
+  \brief  Portable drawing code for drawing arbitrary shapes with
+          simple 2D transformations, implemented for OpenGL.
+*/
+
+#include "Fl_OpenGL_Graphics_Driver.h"
+
+#include <FL/fl_draw.H>
+#include <FL/gl.h>
+#include <FL/math.h>
+
+
+// Event though there are faster versions of the functions in OpenGL,
+// we use the default FLTK implementation for compatibility in the
+// following functions.
+
+// void Fl_OpenGL_Graphics_Driver::push_matrix()
+// void Fl_OpenGL_Graphics_Driver::pop_matrix()
+// void Fl_OpenGL_Graphics_Driver::mult_matrix(double a, double b, double c, double d, double x, double y)
+// void Fl_OpenGL_Graphics_Driver::rotate(double d)
+// double Fl_OpenGL_Graphics_Driver::transform_x(double x, double y)
+// double Fl_OpenGL_Graphics_Driver::transform_y(double x, double y)
+// double Fl_OpenGL_Graphics_Driver::transform_dx(double x, double y)
+// double Fl_OpenGL_Graphics_Driver::transform_dy(double x, double y)
+
+void Fl_OpenGL_Graphics_Driver::begin_points() {
+  glBegin(GL_POINTS);
+}
+
+void Fl_OpenGL_Graphics_Driver::end_points() {
+  glEnd();
+}
+
+void Fl_OpenGL_Graphics_Driver::begin_line() {
+  glBegin(GL_LINE_STRIP);
+}
+
+void Fl_OpenGL_Graphics_Driver::end_line() {
+  glEnd();
+}
+
+void Fl_OpenGL_Graphics_Driver::begin_loop() {
+  glBegin(GL_LINE_LOOP);
+}
+
+void Fl_OpenGL_Graphics_Driver::end_loop() {
+  glEnd();
+}
+
+void Fl_OpenGL_Graphics_Driver::begin_polygon() {
+  glBegin(GL_POLYGON);
+}
+
+void Fl_OpenGL_Graphics_Driver::end_polygon() {
+  glEnd();
+}
+
+void Fl_OpenGL_Graphics_Driver::begin_complex_polygon() {
+  glBegin(GL_POLYGON);
+}
+
+void Fl_OpenGL_Graphics_Driver::gap() {
+  glEnd();
+  glBegin(GL_POLYGON);
+}
+
+// FXIME: non-convex polygons are not supported yet
+// use gluTess* functions to do this; search for gluBeginPolygon
+void Fl_OpenGL_Graphics_Driver::end_complex_polygon() {
+  glEnd();
+}
+
+// remove equal points from closed path
+void Fl_OpenGL_Graphics_Driver::fixloop() { }
+
+void Fl_OpenGL_Graphics_Driver::transformed_vertex(double xf, double yf) {
+  glVertex2d(xf, yf);
+}
+
+void Fl_OpenGL_Graphics_Driver::transformed_vertex0(COORD_T x, COORD_T y) {
+  glVertex2d(x, y);
+}
+
+void Fl_OpenGL_Graphics_Driver::vertex(double x,double y) {
+  transformed_vertex0(x*m.a + y*m.c + m.x, x*m.b + y*m.d + m.y);
+}
+
+void Fl_OpenGL_Graphics_Driver::circle(double cx, double cy, double r) {
+  double rx = r * (m.c ? sqrt(m.a*m.a+m.c*m.c) : fabs(m.a));
+  double ry = r * (m.b ? sqrt(m.b*m.b+m.d*m.d) : fabs(m.d));
+  double rMax;
+  if (ry>rx) rMax = ry; else rMax = rx;
+
+  // from http://slabode.exofire.net/circle_draw.shtml and many other places
+  int num_segments = (int)(10 * sqrt(rMax))+1;
+  double theta = 2 * M_PI / float(num_segments);
+  double tangetial_factor = tan(theta);
+  double radial_factor = cosf(theta);//calculate the radial factor
+  double x = r; //we start at angle = 0
+  double y = 0;
+
+  glBegin(GL_LINE_LOOP);
+  for(int ii = 0; ii < num_segments; ii++) {
+    vertex(x + cx, y + cy); // output vertex
+    double tx = -y;
+    double ty = x;
+    x += tx * tangetial_factor;
+    y += ty * tangetial_factor;
+    x *= radial_factor;
+    y *= radial_factor;
+  } 
+  glEnd(); 
+
+}
+
+#endif // FL_CFG_GFX_OPENGL_VERTEX_CXX
+
+//
+// End of "$Id$".
+//