Hello. I am new to SDL and am wondering if it is possible to use SDL
for keyboard & mouse i/o, audio, events, threads, timing, etc, but use
OpenGL via glut for all video/graphics commands. Will SDL run happily
with something else in control of video? I see on this newsgroup that
some people are working on an integrated OpenGL interface for SDL, but I
don’t think I need that much if I can just use glut seperately and let
SDL do its thing independantly. Also, could I just use SDL video
commands internally, without ever setting a video mode, for bitmap
manipulation and such? Would the SDL_WM commands for window management
still be available? I guess I just need to know to what extent SDL
requires control of this stuff and if I’ll be able to work around it.
Actually, using OpenGL with SDL is very easy. I’m attaching the first
in a set of OpenGL tutorials I will make available on the SDL website
when the OpenGL support is implemented on all platforms.
See ya!
-Sam Lantinga (slouken at devolution.com)
Lead Programmer, Loki Entertainment Software–
“Any sufficiently advanced bug is indistinguishable from a feature”
– Rich Kulawiec
-------------- next part --------------
//
// This code was created by Jeff Molofee '99
// (ported to SDL by Sam Lantinga '2000)
//
// If you’ve found this code useful, please let me know.
//
// Visit me at www.demonews.com/hosted/nehe
//
#include <GL/gl.h> // Header File For The OpenGL32 Library
#include <GL/glu.h> // Header File For The GLu32 Library
#include “SDL.h”
/* A general OpenGL initialization function. Sets all of the initial parameters. */
void InitGL(int Width, int Height) // We call this right after our OpenGL window is created.
{
glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // This Will Clear The Background Color To Black
glClearDepth(1.0); // Enables Clearing Of The Depth Buffer
glDepthFunc(GL_LESS); // The Type Of Depth Test To Do
glEnable(GL_DEPTH_TEST); // Enables Depth Testing
glShadeModel(GL_SMOOTH); // Enables Smooth Color Shading
glMatrixMode(GL_PROJECTION);
glLoadIdentity(); // Reset The Projection Matrix
gluPerspective(45.0f,(GLfloat)Width/(GLfloat)Height,0.1f,100.0f); // Calculate The Aspect Ratio Of The Window
glMatrixMode(GL_MODELVIEW);
}
/* The main drawing function. */
void DrawGLScene()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear The Screen And The Depth Buffer
glLoadIdentity(); // Reset The View
glTranslatef(-1.5f,0.0f,-6.0f); // Move Left 1.5 Units And Into The Screen 6.0
// draw a triangle
glBegin(GL_POLYGON); // start drawing a polygon
glVertex3f( 0.0f, 1.0f, 0.0f); // Top
glVertex3f( 1.0f,-1.0f, 0.0f); // Bottom Right
glVertex3f(-1.0f,-1.0f, 0.0f); // Bottom Left
glEnd(); // we’re done with the polygon
glTranslatef(3.0f,0.0f,0.0f); // Move Right 3 Units
// draw a square (quadrilateral)
glBegin(GL_QUADS); // start drawing a polygon (4 sided)
glVertex3f(-1.0f, 1.0f, 0.0f); // Top Left
glVertex3f( 1.0f, 1.0f, 0.0f); // Top Right
glVertex3f( 1.0f,-1.0f, 0.0f); // Bottom Right
glVertex3f(-1.0f,-1.0f, 0.0f); // Bottom Left
glEnd(); // done with the polygon
// swap buffers to display, since we’re double buffered.
SDL_GL_SwapBuffers();
}
int main(int argc, char **argv)
{
int done;
/* Initialize SDL for video output */
if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
fprintf(stderr, “Unable to initialize SDL: %s\n”, SDL_GetError());
exit(1);
}
/* Create a 640x480 OpenGL screen */
if ( SDL_SetVideoMode(640, 480, 0, SDL_OPENGL) == NULL ) {
fprintf(stderr, “Unable to create OpenGL screen: %s\n”, SDL_GetError());
SDL_Quit();
exit(2);
}
/* Set the title bar in environments that support it */
SDL_WM_SetCaption(“Jeff Molofee’s GL Code Tutorial … NeHe '99”, NULL);
/* Loop, drawing and checking events */
InitGL(640, 480);
done = 0;
while ( ! done ) {
DrawGLScene();
/* This could go in a separate function */
{ SDL_Event event;
while ( SDL_PollEvent(&event) ) {
if ( event.type == SDL_QUIT ) {
done = 1;
}
if ( event.type == SDL_KEYDOWN ) {
if ( event.key.keysym.sym == SDLK_ESCAPE ) {
done = 1;
}
}
}
}
}
SDL_Quit();
return 1;
}
from the looks of things i think i may as well just go ahead
from the looks of things i think i may as well just go ahead