simpleImageFile.cpp

//-
// ==========================================================================
// Copyright 1995,2006,2008 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk
// license agreement provided at the time of installation or download,
// or which otherwise accompanies this software in either electronic
// or hard copy form.
// ==========================================================================
//+

// DESCRIPTION: 
//      Simple Image File plugin. This plugin registers a new image
//  file format against file extension ".moo". Loading any ".moo"
//  image file will produce a procedurally generated colour 
//  spectrum including values outside 0 to 1.
//

#include <maya/MPxImageFile.h>
#include <maya/MImageFileInfo.h>
#include <maya/MImage.h>
#include <maya/MFnPlugin.h>
#include <maya/MStringArray.h>
#include <maya/MIOStream.h>

#if defined(OSMac_MachO_)
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#else
#include <GL/gl.h>
#include <GL/glu.h>
#endif

MString kImagePluginName( "SimpleImageFile");

class SimpleImageFile : public MPxImageFile
{
public:
                    SimpleImageFile();
    virtual         ~SimpleImageFile();
    static void*        creator();
        virtual MStatus open( MString pathname, MImageFileInfo* info);
        virtual MStatus load( MImage& image, unsigned int idx);
        virtual MStatus glLoad( const MImageFileInfo& info, unsigned int imageNumber);

private:
        void                    populateTestImage( float* pixels, unsigned int w, unsigned int h);
};

//
// DESCRIPTION:
SimpleImageFile::SimpleImageFile()
{
}

//
// DESCRIPTION:
SimpleImageFile::~SimpleImageFile()
{
}

//
// DESCRIPTION:
void * SimpleImageFile::creator()
{
    return new SimpleImageFile();
}

//
// DESCRIPTION:
// Configure the image characteristics. A real image file
// format plugin would extract these values from the image
// file header. 
//
MStatus SimpleImageFile::open( MString pathname, MImageFileInfo* info)
{
        if( info)
        {
                info->width( 512);
                info->height( 512);
                info->channels( 3);
                info->pixelType( MImage::kFloat);

                // Only necessary if your format defines a native
                // hardware texture loader
                info->hardwareType( MImageFileInfo::kHwTexture2D);
        }
        return MS::kSuccess;
}


//
// DESCRIPTION:
// Internal helper method to populate our procedural test image
//
void SimpleImageFile::populateTestImage( float* pixels, unsigned int w, unsigned int h)
{
        #define RAINBOW_SCALE 4.0f
        unsigned int x, y;
        for( y = 0; y < h; y++)
        {
                float g = RAINBOW_SCALE * y / (float)h;
                for( x = 0; x < w; x++)
                {
                        float r = RAINBOW_SCALE * x / (float)w;
                        *pixels++ = r;
                        *pixels++ = g;
                        *pixels++ = RAINBOW_SCALE * 1.5f - r - g;
                }
        }
}


//
// DESCRIPTION:
// Load the contents of this image file into an MImage. A real
// file format plugin would extract the pixel data from the image
// file here.
//
MStatus SimpleImageFile::load( MImage& image, unsigned int)
{
        unsigned int w = 512;
        unsigned int h = 512;

        // Create a floating point image and fill it with
        // a pretty rainbow test image.
        //
        image.create( w, h, 3, MImage::kFloat);
        populateTestImage( image.floatPixels(), w, h);
        return MS::kSuccess;
}


//
// DESCRIPTION:
// Load the contents of this image file into an OpenGL texture. A 
// real file format plugin would extract the pixel data from the 
// image file here.
//
MStatus SimpleImageFile::glLoad( const MImageFileInfo& info, unsigned int)
{
        // Create a floating point image
        unsigned int w = info.width();
        unsigned int h = info.height();
        float* pixels = new float[ w * h * 3];
        populateTestImage( pixels, w, h);
        
        // Now load it into OpenGL as a floating point image
        ::glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, w, h, 0, GL_RGB, GL_FLOAT, pixels);

        delete[] pixels;
        return MS::kSuccess;
}


// DESCRIPTION:
MStatus initializePlugin( MObject obj )
{
    MFnPlugin plugin( obj, PLUGIN_COMPANY, "8.0", "Any" );
        MStringArray extensions;
        extensions.append( "moo");
    CHECK_MSTATUS( plugin.registerImageFile(
                                        kImagePluginName,
                                        SimpleImageFile::creator, 
                                        extensions));
    
    return MS::kSuccess;
}

// DESCRIPTION:
MStatus uninitializePlugin( MObject obj )
{
    MFnPlugin plugin( obj );
    CHECK_MSTATUS( plugin.deregisterImageFile( kImagePluginName ) );

    return MS::kSuccess;
}