* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
- * Modifications copyright (c) 2012-2013 Roderick W. Smith
+ * Modifications copyright (c) 2012-2014 Roderick W. Smith
*
* Modifications distributed under the terms of the GNU General Public
* License (GPL) version 3 (GPLv3), a copy of which must be distributed
return NULL;
NewImage->PixelData = (EG_PIXEL *) AllocatePool(Width * Height * sizeof(EG_PIXEL));
if (NewImage->PixelData == NULL) {
- FreePool(NewImage);
+ egFreeImage(NewImage);
return NULL;
}
return NewImage;
} // EG_IMAGE * egCropImage()
+// The following function implements a bilinear image scaling algorithm, based on
+// code presented at http://tech-algorithm.com/articles/bilinear-image-scaling/.
+// Resize an image; returns pointer to resized image if successful, NULL otherwise.
+// Calling function is responsible for freeing allocated memory.
+EG_IMAGE * egScaleImage(IN EG_IMAGE *Image, IN UINTN NewWidth, IN UINTN NewHeight) {
+ EG_IMAGE *NewImage = NULL;
+ EG_PIXEL a, b, c, d;
+ UINTN x, y, Index ;
+ UINTN i, j;
+ UINTN Offset = 0;
+ float x_ratio, y_ratio, x_diff, y_diff;
+
+ if ((Image == NULL) || (Image->Height == 0) || (Image->Width == 0) || (NewWidth == 0) || (NewHeight == 0))
+ return NULL;
+
+ if ((Image->Width == NewWidth) && (Image->Height == NewHeight))
+ return (egCopyImage(Image));
+
+ NewImage = egCreateImage(NewWidth, NewHeight, Image->HasAlpha);
+ if (NewImage == NULL)
+ return NULL;
+
+ x_ratio = ((float)(Image->Width - 1)) / NewWidth;
+ y_ratio = ((float)(Image->Height - 1)) / NewHeight;
+
+ for (i = 0; i < NewHeight; i++) {
+ for (j = 0; j < NewWidth; j++) {
+ x = (UINTN)(x_ratio * j);
+ y = (UINTN)(y_ratio * i);
+ x_diff = (x_ratio * j) - x;
+ y_diff = (y_ratio * i) - y;
+ Index = ((y * Image->Width) + x);
+ a = Image->PixelData[Index];
+ b = Image->PixelData[Index + 1];
+ c = Image->PixelData[Index + Image->Width];
+ d = Image->PixelData[Index + Image->Width + 1];
+
+ // blue element
+ // Yb = Ab(1-Image->Width)(1-Image->Height) + Bb(Image->Width)(1-Image->Height) + Cb(Image->Height)(1-Image->Width) + Db(wh)
+ NewImage->PixelData[Offset].b = (a.b)*(1-x_diff)*(1-y_diff) + (b.b)*(x_diff)*(1-y_diff) +
+ (c.b)*(y_diff)*(1-x_diff) + (d.b)*(x_diff*y_diff);
+
+ // green element
+ // Yg = Ag(1-Image->Width)(1-Image->Height) + Bg(Image->Width)(1-Image->Height) + Cg(Image->Height)(1-Image->Width) + Dg(wh)
+ NewImage->PixelData[Offset].g = (a.g)*(1-x_diff)*(1-y_diff) + (b.g)*(x_diff)*(1-y_diff) +
+ (c.g)*(y_diff)*(1-x_diff) + (d.g)*(x_diff*y_diff);
+
+ // red element
+ // Yr = Ar(1-Image->Width)(1-Image->Height) + Br(Image->Width)(1-Image->Height) + Cr(Image->Height)(1-Image->Width) + Dr(wh)
+ NewImage->PixelData[Offset].r = (a.r)*(1-x_diff)*(1-y_diff) + (b.r)*(x_diff)*(1-y_diff) +
+ (c.r)*(y_diff)*(1-x_diff) + (d.r)*(x_diff*y_diff);
+
+ // alpha element
+ NewImage->PixelData[Offset++].a = (a.a)*(1-x_diff)*(1-y_diff) + (b.a)*(x_diff)*(1-y_diff) +
+ (c.a)*(y_diff)*(1-x_diff) + (d.a)*(x_diff*y_diff);
+
+ } // for (j...)
+ } // for (i...)
+ return NewImage;
+} // EG_IMAGE * egScaleImage()
+
VOID egFreeImage(IN EG_IMAGE *Image)
{
if (Image != NULL) {
return NULL;
// decode it
- NewImage = egDecodeAny(FileData, FileDataLength, 128, WantAlpha);
+ NewImage = egDecodeAny(FileData, FileDataLength, 128 /* arbitrary value */, WantAlpha);
FreePool(FileData);
return NewImage;
EFI_STATUS Status;
UINT8 *FileData;
UINTN FileDataLength;
- EG_IMAGE *NewImage;
+ EG_IMAGE *Image, *NewImage;
if (BaseDir == NULL || Path == NULL)
return NULL;
return NULL;
// decode it
- NewImage = egDecodeAny(FileData, FileDataLength, IconSize, TRUE);
+ Image = egDecodeAny(FileData, FileDataLength, IconSize, TRUE);
FreePool(FileData);
- if ((NewImage->Width != IconSize) || (NewImage->Height != IconSize)) {
- Print(L"Warning: Attempt to load icon of the wrong size from '%s'\n", Path);
- MyFreePool(NewImage);
- NewImage = NULL;
+ if ((Image->Width != IconSize) || (Image->Height != IconSize)) {
+ NewImage = egScaleImage(Image, IconSize, IconSize);
+ if (!NewImage)
+ Print(L"Warning: Unable to scale icon of the wrong size from '%s'\n", Path);
+ egFreeImage(Image);
+ Image = NewImage;
}
- return NewImage;
+ return Image;
} // EG_IMAGE *egLoadIcon()
// Returns an icon of any type from the specified subdirectory using the specified
}
} /* VOID egComposeImage() */
-EG_IMAGE * egEnsureImageSize(IN EG_IMAGE *Image, IN UINTN Width, IN UINTN Height, IN EG_PIXEL *Color)
-{
- EG_IMAGE *NewImage;
-
- if (Image == NULL)
- return NULL;
- if (Image->Width == Width && Image->Height == Height)
- return Image;
-
- NewImage = egCreateFilledImage(Width, Height, Image->HasAlpha, Color);
- if (NewImage == NULL) {
- egFreeImage(Image);
- return NULL;
- }
- Image->HasAlpha = FALSE;
- egComposeImage(NewImage, Image, 0, 0);
- egFreeImage(Image);
-
- return NewImage;
-}
+// EG_IMAGE * egEnsureImageSize(IN EG_IMAGE *Image, IN UINTN Width, IN UINTN Height, IN EG_PIXEL *Color)
+// {
+// EG_IMAGE *NewImage;
+//
+// if (Image == NULL)
+// return NULL;
+// if (Image->Width == Width && Image->Height == Height)
+// return Image;
+//
+// NewImage = egCreateFilledImage(Width, Height, Image->HasAlpha, Color);
+// if (NewImage == NULL) {
+// egFreeImage(Image);
+// return NULL;
+// }
+// Image->HasAlpha = FALSE;
+// egComposeImage(NewImage, Image, 0, 0);
+// egFreeImage(Image);
+//
+// return NewImage;
+// }
//
// misc internal functions