view test/testdyngl.c @ 2659:8da698bc1205 gsoc2008_audio_resampling

Fixed lots of bugs in FIR filtering. Fixed point code is closer to working, but there seems to be overflow in the FIR filter resulting in distortion.
author Aaron Wishnick <schnarf@gmail.com>
date Sun, 22 Jun 2008 00:36:35 +0000
parents 7b53a8401195
children e27bdcc80744
line wrap: on
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/*
 * Small SDL example to demonstrate dynamically loading 
 * OpenGL lib and functions
 *
 * (FYI it was supposed to look like snow in the wind or something...)
 *
 * Compile with :
 * gcc testdyngl.c `sdl-config --libs --cflags` -o testdyngl -DHAVE_OPENGL
 *
 * You can specify a different OpenGL lib on the command line, i.e. :
 * ./testdyngl  /usr/X11R6/lib/libGL.so.1.2
 * or
 * ./testdyngl  /usr/lib/libGL.so.1.0.4496
 *
 */

#include <stdio.h>
#include <stdlib.h>

#include "SDL.h"

#ifdef __MACOS__
#define HAVE_OPENGL
#endif

#ifdef HAVE_OPENGL

#include "SDL_opengl.h"

/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
static void
quit(int rc)
{
    SDL_Quit();
    exit(rc);
}

void *
get_funcaddr(const char *p)
{
    void *f = SDL_GL_GetProcAddress(p);
    if (f) {
        return f;
    } else {
        printf("Unable to get function pointer for %s\n", p);
        quit(1);
    }
    return NULL;
}

typedef struct
{
    void (APIENTRY * glBegin) (GLenum);
    void (APIENTRY * glEnd) ();
    void (APIENTRY * glVertex3f) (GLfloat, GLfloat, GLfloat);
    void (APIENTRY * glClearColor) (GLfloat, GLfloat, GLfloat, GLfloat);
    void (APIENTRY * glClear) (GLbitfield);
    void (APIENTRY * glDisable) (GLenum);
    void (APIENTRY * glEnable) (GLenum);
    void (APIENTRY * glColor4ub) (GLubyte, GLubyte, GLubyte, GLubyte);
    void (APIENTRY * glPointSize) (GLfloat);
    void (APIENTRY * glHint) (GLenum, GLenum);
    void (APIENTRY * glBlendFunc) (GLenum, GLenum);
    void (APIENTRY * glMatrixMode) (GLenum);
    void (APIENTRY * glLoadIdentity) ();
    void (APIENTRY * glOrtho) (GLdouble, GLdouble, GLdouble, GLdouble,
                               GLdouble, GLdouble);
    void (APIENTRY * glRotatef) (GLfloat, GLfloat, GLfloat, GLfloat);
    void (APIENTRY * glViewport) (GLint, GLint, GLsizei, GLsizei);
    void (APIENTRY * glFogf) (GLenum, GLfloat);
}
glfuncs;

void
init_glfuncs(glfuncs * f)
{
    f->glBegin = get_funcaddr("glBegin");
    f->glEnd = get_funcaddr("glEnd");
    f->glVertex3f = get_funcaddr("glVertex3f");
    f->glClearColor = get_funcaddr("glClearColor");
    f->glClear = get_funcaddr("glClear");
    f->glDisable = get_funcaddr("glDisable");
    f->glEnable = get_funcaddr("glEnable");
    f->glColor4ub = get_funcaddr("glColor4ub");
    f->glPointSize = get_funcaddr("glPointSize");
    f->glHint = get_funcaddr("glHint");
    f->glBlendFunc = get_funcaddr("glBlendFunc");
    f->glMatrixMode = get_funcaddr("glMatrixMode");
    f->glLoadIdentity = get_funcaddr("glLoadIdentity");
    f->glOrtho = get_funcaddr("glOrtho");
    f->glRotatef = get_funcaddr("glRotatef");
    f->glViewport = get_funcaddr("glViewport");
    f->glFogf = get_funcaddr("glFogf");
}

#define NB_PIXELS 1000

int
main(int argc, char *argv[])
{
    glfuncs f;
    int i;
    SDL_Event event;
    int done = 0;
    GLfloat pixels[NB_PIXELS * 3];
    const char *gl_library = NULL;      /* Use the default GL library */

    if (argv[1]) {
        gl_library = argv[1];
    }

    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        printf("Unable to init SDL : %s\n", SDL_GetError());
        return (1);
    }

    if (SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1) < 0) {
        printf("Unable to set GL attribute : %s\n", SDL_GetError());
        quit(1);
    }

    if (SDL_GL_LoadLibrary(gl_library) < 0) {
        printf("Unable to dynamically open GL lib : %s\n", SDL_GetError());
        quit(1);
    }

    if (SDL_SetVideoMode(640, 480, 0, SDL_OPENGL) == NULL) {
        printf("Unable to open video mode : %s\n", SDL_GetError());
        quit(1);
    }

    /* Set the window manager title bar */
    SDL_WM_SetCaption("SDL Dynamic OpenGL Loading Test", "testdyngl");

    init_glfuncs(&f);

    for (i = 0; i < NB_PIXELS; i++) {
        pixels[3 * i] = rand() % 250 - 125;
        pixels[3 * i + 1] = rand() % 250 - 125;
        pixels[3 * i + 2] = rand() % 250 - 125;
    }

    f.glViewport(0, 0, 640, 480);

    f.glMatrixMode(GL_PROJECTION);
    f.glLoadIdentity();
    f.glOrtho(-100, 100, -100, 100, -500, 500);

    f.glMatrixMode(GL_MODELVIEW);
    f.glLoadIdentity();

    f.glEnable(GL_DEPTH_TEST);
    f.glDisable(GL_TEXTURE_2D);
    f.glEnable(GL_BLEND);
    f.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    f.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    f.glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    f.glEnable(GL_POINT_SMOOTH);
    f.glHint(GL_POINT_SMOOTH_HINT, GL_NICEST);
    f.glPointSize(5.0f);
    f.glEnable(GL_FOG);
    f.glFogf(GL_FOG_START, -500);
    f.glFogf(GL_FOG_END, 500);
    f.glFogf(GL_FOG_DENSITY, 0.005);

    do {
        f.glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        f.glRotatef(2.0, 1.0, 1.0, 1.0);
        f.glRotatef(1.0, 0.0, 1.0, 1.0);

        f.glColor4ub(255, 255, 255, 255);
        f.glBegin(GL_POINTS);
        for (i = 0; i < NB_PIXELS; i++) {
            f.glVertex3f(pixels[3 * i], pixels[3 * i + 1], pixels[3 * i + 2]);
        }
        f.glEnd();
        SDL_GL_SwapBuffers();

        while (SDL_PollEvent(&event)) {
            if (event.type == SDL_KEYDOWN)
                done = 1;
        }

        SDL_Delay(20);
    }
    while (!done);

    SDL_Quit();
    return 0;
}

#else /* HAVE_OPENGL */

int
main(int argc, char *argv[])
{
    printf("No OpenGL support on this system\n");
    return 1;
}

#endif /* HAVE_OPENGL */