Add a GLPainter class to do all the OpenGL drawing stuff

src/Gui/GLPainter.cpp

@@ -0,0 +1,184 @@
+/***************************************************************************
+ *   Copyright (c) 2013 Werner Mayer <wmayer[at]users.sourceforge.net>     *
+ *                                                                         *
+ *   This file is part of the FreeCAD CAx development system.              *
+ *                                                                         *
+ *   This library is free software; you can redistribute it and/or         *
+ *   modify it under the terms of the GNU Library General Public           *
+ *   License as published by the Free Software Foundation; either          *
+ *   version 2 of the License, or (at your option) any later version.      *
+ *                                                                         *
+ *   This library  is distributed in the hope that it will be useful,      *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU Library General Public License for more details.                  *
+ *                                                                         *
+ *   You should have received a copy of the GNU Library General Public     *
+ *   License along with this library; see the file COPYING.LIB. If not,    *
+ *   write to the Free Software Foundation, Inc., 59 Temple Place,         *
+ *   Suite 330, Boston, MA  02111-1307, USA                                *
+ *                                                                         *
+ ***************************************************************************/
+
+
+#include "PreCompiled.h"
+
+#ifndef _PreComp_
+#endif
+
+#include "GLPainter.h"
+#include "View3DInventorViewer.h"
+
+using namespace Gui;
+
+GLPainter::GLPainter() : viewer(0), logicOp(false), lineStipple(false)
+{
+}
+
+GLPainter::~GLPainter()
+{
+    end();
+}
+
+bool GLPainter::begin(View3DInventorViewer* v)
+{
+    if (viewer)
+        return false;
+    viewer = v;
+
+    // Make current context
+    SbVec2s view = viewer->getGLSize();
+    this->width = view[0];
+    this->height = view[1];
+
+    viewer->glLockNormal();
+
+    glMatrixMode(GL_PROJECTION);
+    glPushMatrix();
+    glLoadIdentity();
+    glOrtho(0, this->width, 0, this->height, -1, 1);
+
+    // Store GL state
+    glPushAttrib(GL_ALL_ATTRIB_BITS);
+    glGetFloatv(GL_DEPTH_RANGE, this->depthrange);
+    glGetDoublev(GL_PROJECTION_MATRIX, this->projectionmatrix);
+
+    glDepthFunc(GL_ALWAYS);
+    glDepthMask(GL_TRUE);
+    glDepthRange(0,0);
+    glEnable(GL_DEPTH_TEST);
+    glDisable(GL_LIGHTING);
+    glEnable(GL_COLOR_MATERIAL);
+    glDisable(GL_BLEND);
+
+    glLineWidth(1.0f);
+    glColor4f(1.0, 1.0, 1.0, 0.0);
+    glViewport(0, 0, this->width, this->height);
+    glDrawBuffer(GL_FRONT);
+
+    return true;
+}
+
+bool GLPainter::end()
+{
+    if (!viewer)
+        return false;
+
+    glFlush();
+    if (this->logicOp) {
+        this->logicOp = false;
+        glDisable(GL_COLOR_LOGIC_OP);
+    }
+    if (this->lineStipple) {
+        this->lineStipple = false;
+        glDisable(GL_LINE_STIPPLE);
+    }
+
+    // Reset original state
+    glDepthRange(this->depthrange[0], this->depthrange[1]);
+    glMatrixMode(GL_PROJECTION);
+    glLoadMatrixd(this->projectionmatrix);
+
+    glPopAttrib();
+    glPopMatrix();
+    
+    // Release the context
+    viewer->glUnlockNormal();
+
+    viewer = 0;
+    return true;
+}
+
+bool GLPainter::isActive() const
+{
+    return viewer != 0;
+}
+
+void GLPainter::setLineWidth(float w)
+{
+    glLineWidth(w);
+}
+
+void GLPainter::setPointSize(float s)
+{
+    glPointSize(s);
+}
+
+void GLPainter::setColor(float r, float g, float b, float a)
+{
+    glColor4f(r, g, b, a);
+}
+
+void GLPainter::setLogicOp(GLenum mode)
+{
+    glEnable(GL_COLOR_LOGIC_OP);
+    glLogicOp(mode);
+    this->logicOp = true;
+}
+
+void GLPainter::setDrawBuffer(GLenum mode)
+{
+    glDrawBuffer(mode);
+}
+
+void GLPainter::setLineStipple(GLint factor, GLushort pattern)
+{
+    glEnable(GL_LINE_STIPPLE);
+    glLineStipple(factor, pattern);
+    this->lineStipple = true;
+}
+
+// Draw routines
+void GLPainter::drawRect(int x1, int y1, int x2, int y2)
+{
+    if (!viewer)
+        return;
+
+    glBegin(GL_LINE_LOOP);
+        glVertex3i(x1, this->height-y1, 0);
+        glVertex3i(x2, this->height-y1, 0);
+        glVertex3i(x2, this->height-y2, 0);
+        glVertex3i(x1, this->height-y2, 0);
+    glEnd();
+}
+
+void GLPainter::drawLine (int x1, int y1, int x2, int y2)
+{
+    if (!viewer)
+        return;
+
+    glBegin(GL_LINES);
+        glVertex3i(x1, this->height-y1, 0);
+        glVertex3i(x2, this->height-y2, 0);
+    glEnd();
+}
+
+void GLPainter::drawPoint(int x, int y)
+{
+    if (!viewer)
+        return;
+
+    glBegin(GL_POINTS);
+        glVertex3i(x, this->height-y, 0);
+    glEnd();
+}