Max 5 API Reference

jit.gl.rbo.c

/*
 * Copyright 2001-2005 - Cycling '74
 * Derek Gerstmann - derek@cycling74.com
 *
 * Struct and associated methods for maintaining an OpenGL 
 * renderbuffer object (RBO) which can be attached to a framebuffer
 * object (FBO) for performing a direct readback via an offscreen 
 * framebuffer.
 *
 * Valid internal formats are any of the following:
 *
 *      - Any format starting with:
 *          RGB, RGBA, DEPTH_COMPONENT, (RGBA8, etc)
 *
 *      - Any of the following stencil buffer formats (not working on NV):
 *          STENCIL_INDEX1_EXT 
 *          STENCIL_INDEX4_EXT     
 *          STENCIL_INDEX8_EXT     
 *          STENCIL_INDEX16_EXT
 */

/****************************************************************************/

#include "jit.gl.rbo.h"

/****************************************************************************/

t_jit_gl_rbo *jit_gl_rbo_new()
{
    t_jit_gl_rbo *x = NULL;

    if(x = jit_getbytes(sizeof(t_jit_gl_rbo)))
    {
        jit_gl_rbo_reset(x);
    }

    return x;
}

void jit_gl_rbo_free(t_jit_gl_rbo *x)
{
    if(x)
    {
        jit_gl_rbo_destroy(x);
        jit_freebytes(x, sizeof(t_jit_gl_rbo));
    }
}

t_jit_err jit_gl_rbo_create(t_jit_gl_rbo *x, GLenum internal, GLint width, GLint height)
{
    GLuint id;
    GLint bound;
    GLint maxw, maxh;
    t_jit_err err;

    // get max renderbuffer size
    err = jit_gl_rbo_query_max_size(x, &maxw, &maxh);
    if(err) return err;

    // verify requested size is within system limits
    if (width > maxw || height > maxh ) 
    {
        jit_object_error((t_object *)x,"jit.gl.rbo: unable to create renderbuffer, requested size exceeds system capabilites: [%d,%d] > [%d,%d]", width, height, maxw, maxh);
        return JIT_ERR_GENERIC;
    }

    // generate a new renderbuffer 
    if(!x->id)
    {
        glGenRenderbuffersEXT(1, &id);
        x->id = id;
    }

    // get current renderbuffer id
    glGetIntegerv( GL_RENDERBUFFER_BINDING_EXT, &bound );
    
    // only bind if renderbuffer is not active
    if (x->id != bound) 
    {
        err = jit_gl_rbo_bind(x);
        if(err) return err;
    }

    // allocate renderbuffer storage
    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, internal, width, height );
    
    // only unbind if renderbuffer is not active
    if (x->id != bound) 
    {
        err = jit_gl_rbo_unbind(x);
        if(err) return err;
    }

    // save data members
    x->width = width;
    x->height = height;
    x->internal = internal;
    return JIT_ERR_NONE;
}

t_jit_err jit_gl_rbo_bind(t_jit_gl_rbo *x)
{
    GLint id;

    if(!x)
        return JIT_ERR_INVALID_PTR;

    // bind the renderbuffer
    if(x->id)
    {
        glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, x->id);
        jit_gl_report_error("jit.gl: error binding renderbuffer object!");
    }
    return JIT_ERR_NONE;      
}

t_jit_err jit_gl_rbo_unbind(t_jit_gl_rbo *x)
{
    if(!x)
        return JIT_ERR_INVALID_PTR;

    if(x->id)
    {
        glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, 0);
        jit_gl_report_error("jit.gl.rbo: error unbinding renderbuffer object!");
    }
    return JIT_ERR_NONE;
}

t_jit_err jit_gl_rbo_destroy(t_jit_gl_rbo *x)
{
    GLuint id;

    if(!x)
        return JIT_ERR_INVALID_PTR;

    if(x->id)
    {
        id = x->id;
        glDeleteRenderbuffersEXT(1, &id);
        x->id = 0;
    }

    jit_gl_rbo_reset(x);
    return JIT_ERR_NONE;
}

t_jit_err jit_gl_rbo_reset(t_jit_gl_rbo *x)
{
    if(!x)
        return JIT_ERR_INVALID_PTR;

    x->id = 0;
    x->width = 0;
    x->height = 0;
    x->internal = -1;
    return JIT_ERR_NONE;
}

t_jit_err jit_gl_rbo_query_max_size(t_jit_gl_rbo *x, GLint *width, GLint *height)
{
    GLint max = 0;
    glGetIntegerv( GL_MAX_RENDERBUFFER_SIZE_EXT, &max );

    *width = max;
    *height = max;

    return JIT_ERR_NONE;
}
/****************************************************************************/

Copyright © 2008, Cycling '74