2b3567c83c
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3-porting@11055 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
143 lines
3.7 KiB
C++
143 lines
3.7 KiB
C++
//
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// "$Id$"
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//
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// Portable drawing routines for the Fast Light Tool Kit (FLTK).
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//
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// Copyright 1998-2016 by Bill Spitzak and others.
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//
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// This library is free software. Distribution and use rights are outlined in
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// the file "COPYING" which should have been included with this file. If this
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// file is missing or damaged, see the license at:
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//
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// http://www.fltk.org/COPYING.php
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//
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// Please report all bugs and problems on the following page:
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//
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// http://www.fltk.org/str.php
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//
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#ifndef FL_CFG_GFX_OPENGL_VERTEX_CXX
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#define FL_CFG_GFX_OPENGL_VERTEX_CXX
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/**
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\file opengl_vertex.cxx
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\brief Portable drawing code for drawing arbitrary shapes with
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simple 2D transformations, implemented for OpenGL.
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*/
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#include "Fl_OpenGL_Graphics_Driver.h"
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#include <FL/fl_draw.H>
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#include <FL/gl.h>
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#include <FL/math.h>
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// Event though there are faster versions of the functions in OpenGL,
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// we use the default FLTK implementation for compatibility in the
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// following functions.
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// void Fl_OpenGL_Graphics_Driver::push_matrix()
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// void Fl_OpenGL_Graphics_Driver::pop_matrix()
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// void Fl_OpenGL_Graphics_Driver::mult_matrix(double a, double b, double c, double d, double x, double y)
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// void Fl_OpenGL_Graphics_Driver::rotate(double d)
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// double Fl_OpenGL_Graphics_Driver::transform_x(double x, double y)
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// double Fl_OpenGL_Graphics_Driver::transform_y(double x, double y)
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// double Fl_OpenGL_Graphics_Driver::transform_dx(double x, double y)
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// double Fl_OpenGL_Graphics_Driver::transform_dy(double x, double y)
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void Fl_OpenGL_Graphics_Driver::begin_points() {
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glBegin(GL_POINTS);
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}
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void Fl_OpenGL_Graphics_Driver::end_points() {
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glEnd();
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}
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void Fl_OpenGL_Graphics_Driver::begin_line() {
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glBegin(GL_LINE_STRIP);
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}
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void Fl_OpenGL_Graphics_Driver::end_line() {
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glEnd();
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}
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void Fl_OpenGL_Graphics_Driver::begin_loop() {
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glBegin(GL_LINE_LOOP);
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}
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void Fl_OpenGL_Graphics_Driver::end_loop() {
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glEnd();
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}
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void Fl_OpenGL_Graphics_Driver::begin_polygon() {
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glBegin(GL_POLYGON);
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}
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void Fl_OpenGL_Graphics_Driver::end_polygon() {
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glEnd();
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}
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void Fl_OpenGL_Graphics_Driver::begin_complex_polygon() {
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glBegin(GL_POLYGON);
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}
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void Fl_OpenGL_Graphics_Driver::gap() {
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glEnd();
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glBegin(GL_POLYGON);
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}
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// FXIME: non-convex polygons are not supported yet
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// use gluTess* functions to do this; search for gluBeginPolygon
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void Fl_OpenGL_Graphics_Driver::end_complex_polygon() {
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glEnd();
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}
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// remove equal points from closed path
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void Fl_OpenGL_Graphics_Driver::fixloop() { }
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void Fl_OpenGL_Graphics_Driver::transformed_vertex(double xf, double yf) {
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glVertex2d(xf, yf);
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}
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void Fl_OpenGL_Graphics_Driver::transformed_vertex0(COORD_T x, COORD_T y) {
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glVertex2d(x, y);
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}
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void Fl_OpenGL_Graphics_Driver::vertex(double x,double y) {
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transformed_vertex0(x*m.a + y*m.c + m.x, x*m.b + y*m.d + m.y);
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}
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void Fl_OpenGL_Graphics_Driver::circle(double cx, double cy, double r) {
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double rx = r * (m.c ? sqrt(m.a*m.a+m.c*m.c) : fabs(m.a));
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double ry = r * (m.b ? sqrt(m.b*m.b+m.d*m.d) : fabs(m.d));
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double rMax;
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if (ry>rx) rMax = ry; else rMax = rx;
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// from http://slabode.exofire.net/circle_draw.shtml and many other places
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int num_segments = (int)(10 * sqrt(rMax))+1;
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double theta = 2 * M_PI / float(num_segments);
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double tangetial_factor = tan(theta);
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double radial_factor = cosf(theta);//calculate the radial factor
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double x = r; //we start at angle = 0
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double y = 0;
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glBegin(GL_LINE_LOOP);
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for(int ii = 0; ii < num_segments; ii++) {
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vertex(x + cx, y + cy); // output vertex
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double tx = -y;
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double ty = x;
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x += tx * tangetial_factor;
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y += ty * tangetial_factor;
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x *= radial_factor;
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y *= radial_factor;
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}
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glEnd();
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}
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#endif // FL_CFG_GFX_OPENGL_VERTEX_CXX
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//
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// End of "$Id$".
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//
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