public static void Write(Image bmp, Stream stream)
{
DLLImports.gdImageSaveAlpha(bmp.gdImageStructPtr, 1);
//MARSHALLING?
DLLImports.gdImageStruct gdImageStruct = Marshal.PtrToStructure <DLLImports.gdImageStruct>(bmp.gdImageStructPtr);
var wrapper = new gdStreamWrapper(stream);
DLLImports.gdImagePngCtx(ref gdImageStruct, ref wrapper.IOCallbacks);
}
/* constructors */
private Image(int width, int height)
{
if (width > 0 && height > 0)
{
gdImageStructPtr = DLLImports.gdImageCreateTrueColor(width, height);
}
else
{
string rsc = string.Format(Strings.CreateInvalidParameters, width, height);
throw new InvalidOperationException(rsc);
}
}
//add png specific method later
public static void Write(Image img, string filePath)
{
DLLImports.gdImageSaveAlpha(img.gdImageStructPtr, 1);
if (!DLLImports.gdSupportsFileType(filePath, true))
{
throw new InvalidOperationException(SR.Format(SR.FileTypeNotSupported, filePath));
}
else
{
if (!DLLImports.gdImageFile(img.gdImageStructPtr, filePath))
{
throw new FileLoadException(SR.Format(SR.WriteToFileFailed, filePath));
}
}
}
////test...
//public static readonly double[,] AlphaMatrix040 = { {0.4, 0, 0, 0},
// {0, 1, 0, 0 },
// {0, 0, 1, 0},
// {0, 0, 0, 1}
// };
//Resizing
public static Image Resize(this Image sourceImage, int width, int height)
{
if (width > 0 && height > 0)
{
Image destinationImage = Image.Create(width, height);
//turn off alpha blending to overwrite it right
DLLImports.gdImageAlphaBlending(destinationImage.gdImageStructPtr, 0);
DLLImports.gdImageCopyResized(destinationImage.gdImageStructPtr, sourceImage.gdImageStructPtr, 0, 0, 0, 0,
destinationImage.WidthInPixels, destinationImage.HeightInPixels, sourceImage.WidthInPixels, sourceImage.HeightInPixels);
return(destinationImage);
}
else
{
throw new InvalidOperationException(SR.Format(SR.ResizeInvalidParameters, width, height));
}
}
public static Image Load(Stream stream)
{
if (stream != null)
{
unsafe
{
IntPtr pNativeImage = IntPtr.Zero;
var wrapper = new gdStreamWrapper(stream);
pNativeImage = DLLImports.gdImageCreateFromPngCtx(ref wrapper.IOCallbacks);
DLLImports.gdImageStruct *pStruct = (DLLImports.gdImageStruct *)pNativeImage;
Image toRet = Image.Create(pStruct->sx, pStruct->sx);
DLLImports.gdImageDestroy(toRet.gdImageStructPtr);
toRet.gdImageStructPtr = pNativeImage;
return(toRet);
}
}
else
{
throw new InvalidOperationException(SR.NullStreamReferenced);
}
}
//add jpg specific method later
public static Image Load(string filePath)
{
if (!File.Exists(filePath))
{
throw new FileNotFoundException(string.Format(Strings.MalformedFilePath, filePath));
}
else if (DLLImports.gdSupportsFileType(filePath, false))
{
Image img = new Image(DLLImports.gdImageCreateFromFile(filePath));
if (!img.TrueColor)
{
DLLImports.gdImagePaletteToTrueColor(img.gdImageStructPtr);
}
return(img);
}
else
{
throw new FileLoadException(string.Format(Strings.FileTypeNotSupported, filePath));
}
}
//Stamping an Image onto another
public static void Draw(this Image destinationImage, Image sourceImage, int xOffset, int yOffset)
{
//turn alpha blending on for drawing
DLLImports.gdImageAlphaBlending(destinationImage.gdImageStructPtr, 1);
unsafe
{
DLLImports.gdImageStruct *pStructSource = (DLLImports.gdImageStruct *)sourceImage.gdImageStructPtr;
DLLImports.gdImageStruct *pStructDest = (DLLImports.gdImageStruct *)destinationImage.gdImageStructPtr;
//loop through the source image
for (int y = 0; y < sourceImage.HeightInPixels; y++)
{
for (int x = 0; x < sourceImage.WidthInPixels; x++)
{
//ignores what falls outside the bounds of dsetination image
if ((y + yOffset) >= destinationImage.HeightInPixels || (x + xOffset) >= destinationImage.WidthInPixels)
{
continue;
}
int sourceColor = pStructSource->tpixels[y][x];
int alpha = (sourceColor >> 24) & 0xff;
//should not have 127 as magic
if (alpha == 127)
{
continue;
}
int destColor = pStructDest->tpixels[y + yOffset][x + xOffset];
int blendedColor = DLLImports.gdAlphaBlend(destColor, sourceColor);
pStructDest->tpixels[y + yOffset][x + xOffset] = blendedColor;
}
}
}
}
/* Release */
public void ReleaseStruct()
{
DLLImports.gdImageDestroy(gdImageStructPtr);
}