[SDL] 2D above OpenGL graphics

[kuon - Nicolas Goy - 時期精霊]

Nuno Santos wrote:
> Hi,
> 
> Yes, i was meaning that! I see!
> 
> My first goal in that direction was to include some text above my 
> scenes! Do you recommend me the same strategy?
> 
> Cheers,
> 
> Nuno
> 

Hoy.
Opengl can be a very good 2d api.

Just do:

glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();

glOrtho2d(0, screenWidth, 0, screenHeight);


glMatrixMode(GL_MODELVIEW);
// some 2d drawing like

glRasterPos2i(100, 100); // draw at position 100 100 pixel
glutBitmapCharacter(GLUT_BITMAP_8_BY_13, 'H'); // Will draw a H at 100 
100, for more advanced text handling or if you don't wanna link with 
glut, check the opengl.org site for font rastering, SDL also provide 
true type library.

glPopMatrix();
glMatrixMode(GL_PROJECTION);
glPopMatrix();


Some tips:

Always draw your 2d (interface or anything) AFTER the scene.

Disable as much option as you can (man glPushAttrib) like depth test, 
blending (you need it if image has alpha value), texture, lighting... 
before drawing the 2d layer.


Regards



-- 
Kuon
CEO - Goyman.com SA
http://www.goyman.com/

"Computers should not stop working when the users' brain does."
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