#include "glextensions.h"
#include "scene.h"
#include <QtGui>
#include <QGLWidget>
class GraphicsView : public QGraphicsView
{
public:
GraphicsView()
{
setWindowTitle(tr("Boxes"));
setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);
}
protected:
void resizeEvent(QResizeEvent *event) {
if (scene())
scene()->setSceneRect(QRect(QPoint(0, 0), event->size()));
QGraphicsView::resizeEvent(event);
}
};
inline bool matchString(const char *extensionString, const char *subString)
{
int subStringLength = strlen(subString);
return (strncmp(extensionString, subString, subStringLength) == 0)
&& ((extensionString[subStringLength] == ' ') || (extensionString[subStringLength] == '\0'));
}
bool necessaryExtensionsSupported()
{
const char *extensionString = reinterpret_cast<const char *>(glGetString(GL_EXTENSIONS));
const char *p = extensionString;
const int GL_EXT_FBO = 1;
const int GL_ARB_VS = 2;
const int GL_ARB_FS = 4;
const int GL_ARB_SO = 8;
int extensions = 0;
while (*p) {
if (matchString(p, "GL_EXT_framebuffer_object"))
extensions |= GL_EXT_FBO;
else if (matchString(p, "GL_ARB_vertex_shader"))
extensions |= GL_ARB_VS;
else if (matchString(p, "GL_ARB_fragment_shader"))
extensions |= GL_ARB_FS;
else if (matchString(p, "GL_ARB_shader_objects"))
extensions |= GL_ARB_SO;
while ((*p != ' ') && (*p != '\0'))
++p;
if (*p == ' ')
++p;
}
return (extensions == 15);
}
int main(int argc, char **argv)
{
QApplication app(argc, argv);
if ((QGLFormat::openGLVersionFlags() & QGLFormat::OpenGL_Version_1_5) == 0) {
QMessageBox::critical(0, "OpenGL features missing",
"OpenGL version 1.5 or higher is required to run this demo.\n"
"The program will now exit.");
return -1;
}
int maxTextureSize = 1024;
QGLWidget *widget = new QGLWidget(QGLFormat(QGL::SampleBuffers));
widget->makeCurrent();
if (!necessaryExtensionsSupported()) {
QMessageBox::critical(0, "OpenGL features missing",
"The OpenGL extensions required to run this demo are missing.\n"
"The program will now exit.");
delete widget;
return -2;
}
if (!getGLExtensionFunctions().resolve(widget->context())) {
QMessageBox::critical(0, "OpenGL features missing",
"Failed to resolve OpenGL functions required to run this demo.\n"
"The program will now exit.");
delete widget;
return -3;
}
QMessageBox::information(0, "For your information",
"This demo can be GPU and CPU intensive and may\n"
"work poorly or not at all on your system.");
widget->makeCurrent();
Scene scene(1024, 768, maxTextureSize);
GraphicsView view;
view.setViewport(widget);
view.setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
view.setScene(&scene);
view.show();
return app.exec();
}