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technologist
05-12-2017, 08:10 PM
Hi everyone, new to OpenGL here.

I can experiment for giggles by changing glutInitWindowSize and WindowSize but doing so with no perceptible effect. Why can't I change my glutInitWindowSize/WindowSize?
#include <windows.h> // for MS Windows
#include <GL/glut.h> // GLUT, include glu.h and gl.h

/* Handler for window-repaint event. Call back when the window first appears and
whenever the window needs to be re-painted. */
void display() {
glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Set background color to black and opaque
glClear(GL_COLOR_BUFFER_BIT); // Clear the color buffer (background)

// Draw a Red 1x1 Square centered at origin
glBegin(GL_QUADS); // Each set of 4 vertices form a quad
glColor3f(1.0f, 0.0f, 0.0f); // Red
glVertex2f(-0.5f, -0.5f); // x, y
glVertex2f( 0.5f, -0.5f);
glVertex2f( 0.5f, 0.5f);
glVertex2f(-0.5f, 0.5f);
glEnd();

glFlush(); // Render now
}

/* Main function: GLUT runs as a console application starting at main() */
int main(int argc, char** argv) {
glutInit(&argc, argv); // Initialize GLUT
glutCreateWindow("OpenGL Setup Test"); // Create a window with the given title
glutInitWindowSize(320, 320); // Set the window's initial width & height
glutInitWindowPosition(50, 50); // Position the window's initial top-left corner
glutDisplayFunc(display); // Register display callback handler for window re-paint
glutMainLoop(); // Enter the event-processing loop
return 0;
}
int main(int argc, char** argv) {
glutInit(&argc, argv); // Initialize GLUT
glutCreateWindow("OpenGL Super Setup Test"); // Create a window with the given title
glutInitWindowSize(250, 280); // Set the window's initial width & height
glutInitWindowPosition(45, 45); // Position the window's initial top-left corner
glutDisplayFunc(display); // Register display callback handler for window re-paint
glutMainLoop(); // Enter the event-processing loop
return 0;
}

technologist
05-13-2017, 12:12 PM
How do I draw against a 1920 x 1080 screen then for eg? How do I transition from console screen to a screen like 1920 x 1080?

Dark Photon
05-13-2017, 06:09 PM
Call glutInitWindowSize() and glutInitWindowPosition() before glutCreateWindow().

If you want to resize/reposition a window after creation, use glutPositionWindow() or glutReshapeWindow().

Re 1920x1080, if you want to make your window full-screen, see glutFullScreen().