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adam17

GLEW alternative

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ive been toying with GLEW for a while and many people have pointed out that its not OGL 2.0 compliant. can anyone suggest something similar to GLEW but is OGL 2.0?

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Really depends what you mean by "Opengl 2.0 compliant", if you mean "Does it support every single one of the ogl 2.0 extensions, maybe not, but until you need them, I think you should use GLEW

Mark

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ive been looking around for a different way to do shaders. if you have seen or read any of my last thread [link]http://www.gamedev.net/community/forums/topic.asp?topic_id=328736[/link] it would make sense to why i want to switch.

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why not just load the extensions yourself the manual way? ...it is pretty basic todo, a little tedious i know but i personally prefer it that way,just load the extensions you know you are going to use. GLEW and GLEE just take all the fun out of it LOL

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I looked through your other thread, so unless you don't want to use GLSL(or don't want to use the opengl functions to use it), I don't know what's wrong with GLEW (you can use GLee if you want, but I don't see what you need that GLEW lacks). The below is a working example (which lacks a lot error detection) of Using GLSL with GLEW (1.3.3) and it's using 2.0 interface to GLSL (so glCreateProgram instead of glCreateProgramObjectARB)


#include <SDL/SDL.h>
#include <GL/glew.h> //replaces SDL_opengl.h
#include <iostream>

using namespace std;

const int Width = 1280;
const int Height = 1024;
SDL_Surface *screen;
bool done = false;

GLUquadricObj *quadratic;

GLuint programObject;
const GLcharARB *vextexProgram=
"varying vec3 normal, lightDir;"
"void main()"
"{"
" lightDir = normalize(vec3(gl_LightSource[0].position));"
" normal = normalize(gl_NormalMatrix * gl_Normal);"
" gl_Position = ftransform();"
"}";
const GLcharARB* fragmentProgram=
"varying vec3 normal, lightDir;"
"void main()"
"{"
" float intensity;"
" vec3 n;"
" vec4 color;"
" n = normalize(normal);"
" intensity = max(dot(lightDir,n),0.0); "
" if (intensity > 0.98)"
" color = vec4(0.8,0.8,0.8,1.0);"
" else if (intensity > 0.5)"
" color = vec4(0.4,0.4,0.8,1.0); "
" else if (intensity > 0.25)"
" color = vec4(0.2,0.2,0.4,1.0);"
" else"
" color = vec4(0.1,0.1,0.1,1.0);"
" gl_FragColor = color;"
"}";

void initWindow(){
SDL_Init(SDL_INIT_EVERYTHING);
SDL_GL_SetAttribute(SDL_GL_RED_SIZE,8);
SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE,8);
SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE,8);
SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE,8);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER,1);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE,24);
screen = SDL_SetVideoMode(Width, Height, 32, SDL_OPENGL | SDL_HWSURFACE | SDL_FULLSCREEN);
SDL_WM_SetCaption ("SDL+OpenGL+GLEW", NULL);
}

void initGL(){
glViewport(0, 0, Width,Height);

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0f,Width/Height,0.1f,1000.0f);
glMatrixMode(GL_MODELVIEW);

glClearColor(0.5f, 0.4f, 0.3f, 1.0);
glEnable(GL_DEPTH_TEST);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

glEnable(GL_LIGHTING);
float AmbientColor[] = { 0.0f, 0.1f, 0.2f, 0.0f };
glLightfv(GL_LIGHT0, GL_AMBIENT, AmbientColor);
float DiffuseColor[] = { 1.0f, 1.0f, 1.0f, 1.0f };
glLightfv(GL_LIGHT0, GL_DIFFUSE, DiffuseColor);
float SpecularColor[] = { 0.0f, 0.0f, 0.0f, 0.0f };
glLightfv(GL_LIGHT0, GL_SPECULAR, SpecularColor);
float Position[] = { 100.0f, 100.0f, 100.0f, 1.0f };
glLightfv(GL_LIGHT0, GL_POSITION, Position);

glEnable(GL_LIGHT0);

quadratic=gluNewQuadric();
gluQuadricNormals(quadratic, GLU_SMOOTH);
}

void drawGL(){
static float xrot=0.0;
static float yrot=0.0;
xrot += 0.16;
yrot += 0.12;
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glLoadIdentity( );

glTranslatef( 0.0f, 0.0f, -5.0f);

glRotatef( xrot, 1.0f, 0.0f, 0.0f);
glRotatef( yrot, 0.0f, 1.0f, 0.0f);

//gluSphere(quadratic,1.3f,32,32);
gluCylinder(quadratic,1.3f,0.6f,1.3f,256,256);
}

void processInput(){
SDL_Event event;
while (SDL_PollEvent (&event)){
switch (event.type){
case SDL_KEYDOWN:
switch (event.key.keysym.sym){
case SDLK_ESCAPE:
done = true;
break;
default:
break;
}
break;
case SDL_QUIT:
done = true;
break;
default:
break;
}
}
}

void setupshader(){
GLuint vertexShader,fragmentShader;

vertexShader=glCreateShader(GL_VERTEX_SHADER);
fragmentShader=glCreateShader(GL_FRAGMENT_SHADER);

glShaderSource(vertexShader, 1, &vextexProgram,NULL);
glShaderSource(fragmentShader, 1, &fragmentProgram,NULL);

glCompileShader(vertexShader);
glCompileShader(fragmentShader);

programObject = glCreateProgram();
glAttachShader(programObject,fragmentShader);
glAttachShader(programObject,vertexShader);

glLinkProgram(programObject);
glUseProgram(programObject);

}

int main(int argc, char *argv[]){
initWindow();
initGL();

GLenum err = glewInit();
if (err != GLEW_OK)
cout << reinterpret_cast<const char*>(glewGetErrorString(err)) << endl;
if (!GLEW_VERSION_2_0){
cout << "Need OpenGL 2.0" << endl;
exit(-1);
}
setupshader();
while (!done){
processInput();
drawGL();
SDL_GL_SwapBuffers();
}
SDL_Quit();
}



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