OpenGL
GLCtrl widget example
main.cpp
#include <CtrlLib/CtrlLib.h>
#include <GLCtrl/GLCtrl.h>
using namespace Upp;
struct OpenGLExample : GLCtrl {
Point point;
void GLPaint() override {
StdView();
double t = 13 * point.x;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glLoadIdentity();
glPushMatrix();
glTranslatef(0, 0, -6);
glRotated(t / 30.0, 0, 1, 0);
glRotated(t / 40.0, 1, 0, 0);
glRotated(t / 5.0, 0, 0, 1);
glBegin(GL_TRIANGLE_FAN);
glColor4d(0.8, 0.4, 0.2, 1);
glVertex3f(0.0f, 0.0f, 0.0f);
for(int i = 0; i < 50; i++) {
double u = M_2PI * i / 49;
glColor4d(i / 50.0, 0.5 + i / 100.0, 0.7 - i / 150.0, 1);
glVertex3d(sin(u), cos(u), 1.0f);
}
glEnd();
glBegin(GL_TRIANGLE_FAN);
glColor4d(0.8, 0.4, 0.2, 1);
glVertex3f(0.0f, 0.0f, 3.0f);
for(int i = 0; i < 50; i++) {
double u = M_2PI * i / 49;
glColor4d(0.7, 0.5 - i / 100.0, 0.7 + i / 150.0, 1);
glVertex3d(sin(u), cos(u), 1.0f);
}
glEnd();
glPopMatrix();
t = 13 * point.y;
float sn = (float)sin(t / 300);
float cs = (float)cos(t / 300);
glTranslatef(sn + cs, sn, -6 - cs);
glRotated(t / 12.0, 0, 0, 1);
glRotated(t / 15.0, 0, 1, 0);
glRotated(t / 17.0, 1, 0, 0);
glBegin(GL_TRIANGLE_STRIP);
glVertex3f(0.0f, 0.0f, 0.0f);
glColor4d(1, 0, 0, 0.5);
glVertex3d(-1, 0, 0);
glVertex3d(1, 0, 0);
glVertex3d(0, 0.87, 0);
glColor4d(0, 1, 0, 0.5);
glVertex3d(0, 0, 1.67);
glEnd();
}
void LeftDown(Point, dword) override
{ // Demonstrates how to create a screenshot of opengl widget
ExecuteGL([&] {
Size sz=GetSize();
ImageBuffer ib(sz);
glReadPixels(0,0,sz.cx,sz.cy,GL_BGRA_EXT,GL_UNSIGNED_BYTE,(GLvoid*)~ib);
if(!glGetError()){
// Flip
Buffer<RGBA> temp(sz.cx);
for(int i = 0; i < sz.cy / 2; i++){
memcpy(temp, ib[i], sz.cx * sizeof(RGBA));
memcpy(ib[i], ib[sz.cy - 1 - i], sz.cx * sizeof(RGBA));
memcpy(ib[sz.cy - 1 - i], temp, sz.cx * sizeof(RGBA));
}
// Flatten alpha channel
for(RGBA& t : ib)
t.a = 255;
// Save image
String p = SelectFileSaveAs("Portable Network Graphics (*.png)\t*.png");
if(p.GetCount())
PNGEncoder().SaveFile(p, ib);
}
});
}
void MouseMove(Point p, dword) override {
point = p;
Refresh();
}
};
GUI_APP_MAIN
{
Ctrl::GlobalBackPaint();
TopWindow win;
OpenGLExample gl;
gl.SetFrame(InsetFrame());
win.Title("OpenGL Reference");
win.Add(gl.HSizePos(10, 10).VSizePos(10, 10));
win.Sizeable().Zoomable();
win.Open();
win.Run();
}
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