2D Graphics with OpenGL

Graphics and GPU Programming Programming OpenGL

Started by ThomasHopf June 29, 2001 07:38 AM

1 comment, last by ThomasHopf 22 years, 9 months ago

122

Author

June 29, 2001 07:38 AM

Hi! Is there any possiblity to use common 2d functions like bitmap blitting or drawing lines with openGL? i am searching for a solution that works with pixel coordinates, so i can blit images or draw lines like with the gdi, but gdi isn''t working with my GL code (because of the double buffering?)

Julio

116

June 29, 2001 07:47 AM

well, you can do 2d in OpenGL, but it isn''t as easy as drawing sprites. Instead of sprites you use textured quads. to get the 2d world set up, do this:
glViewport(0,0,screen_width,screen_height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0f,screen_width,screen_height,0.0f,-1.0f,1.0f);
glMatrixMode(GL_MODELVIEW);

then, you can say glVertex2f(x,y) to draw your quads.

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mittens

1,323

June 29, 2001 01:08 PM

Check out NeHe''s lesson 21 tutorial (at least... I think thats what it is), well, whatever number it is, it shows a complete 2D game done in OpenGL. Check it out... NOW!

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Trent (ShiningKnight)
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