#include "../refind/global.h"
#include "../refind/lib.h"
#include "../refind/screen.h"
+#include "../refind/mystrings.h"
#include "../include/refit_call_wrapper.h"
#include "lodepng.h"
#define MAX_FILE_SIZE (1024*1024*1024)
+// Multiplier for pseudo-floating-point operations in egScaleImage().
+// A value of 4096 should keep us within limits on 32-bit systems, but I've
+// seen some minor artifacts at this level, so give it a bit more precision
+// on 64-bit systems....
+#if defined(EFIX64) | defined(EFIAARCH64)
+#define FP_MULTIPLIER (UINTN) 65536
+#else
+#define FP_MULTIPLIER (UINTN) 4096
+#endif
+
#ifndef __MAKEWITH_GNUEFI
#define LibLocateHandle gBS->LocateHandleBuffer
#define LibOpenRoot EfiLibOpenRoot
// 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.
+// NOTE: x_ratio, y_ratio, x_diff, and y_diff should really be float values;
+// however, I've found that my 32-bit Mac Mini has a buggy EFI (or buggy CPU?), which
+// causes this function to hang on float-to-UINT8 conversions on some (but not all!)
+// float values. Therefore, this function uses integer arithmetic but multiplies
+// all values by FP_MULTIPLIER to achieve something resembling the sort of precision
+// needed for good results.
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;
+ UINTN x_ratio, y_ratio, x_diff, y_diff;
if ((Image == NULL) || (Image->Height == 0) || (Image->Width == 0) || (NewWidth == 0) || (NewHeight == 0))
return NULL;
if (NewImage == NULL)
return NULL;
- x_ratio = ((float)(Image->Width - 1)) / NewWidth;
- y_ratio = ((float)(Image->Height - 1)) / NewHeight;
+ x_ratio = ((Image->Width - 1) * FP_MULTIPLIER) / NewWidth;
+ y_ratio = ((Image->Height - 1) * FP_MULTIPLIER) / 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;
+ x = (j * (Image->Width - 1)) / NewWidth;
+ y = (i * (Image->Height - 1)) / NewHeight;
+ x_diff = (x_ratio * j) - x * FP_MULTIPLIER;
+ y_diff = (y_ratio * i) - y * FP_MULTIPLIER;
Index = ((y * Image->Width) + x);
a = Image->PixelData[Index];
b = Image->PixelData[Index + 1];
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);
+ NewImage->PixelData[Offset].b = ((a.b) * (FP_MULTIPLIER - x_diff) * (FP_MULTIPLIER - y_diff) +
+ (b.b) * (x_diff) * (FP_MULTIPLIER - y_diff) +
+ (c.b) * (y_diff) * (FP_MULTIPLIER - x_diff) +
+ (d.b) * (x_diff * y_diff)) / (FP_MULTIPLIER * FP_MULTIPLIER);
// 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);
+ NewImage->PixelData[Offset].g = ((a.g) * (FP_MULTIPLIER - x_diff) * (FP_MULTIPLIER - y_diff) +
+ (b.g) * (x_diff) * (FP_MULTIPLIER - y_diff) +
+ (c.g) * (y_diff) * (FP_MULTIPLIER - x_diff) +
+ (d.g) * (x_diff * y_diff)) / (FP_MULTIPLIER * FP_MULTIPLIER);
// 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);
+ NewImage->PixelData[Offset].r = ((a.r) * (FP_MULTIPLIER - x_diff) * (FP_MULTIPLIER - y_diff) +
+ (b.r) * (x_diff) * (FP_MULTIPLIER - y_diff) +
+ (c.r) * (y_diff) * (FP_MULTIPLIER - x_diff) +
+ (d.r) * (x_diff * y_diff)) / (FP_MULTIPLIER * FP_MULTIPLIER);
// 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);
-
+ NewImage->PixelData[Offset++].a = ((a.a) * (FP_MULTIPLIER - x_diff) * (FP_MULTIPLIER - y_diff) +
+ (b.a) * (x_diff) * (FP_MULTIPLIER - y_diff) +
+ (c.a) * (y_diff) * (FP_MULTIPLIER - x_diff) +
+ (d.a) * (x_diff * y_diff)) / (FP_MULTIPLIER * FP_MULTIPLIER);
} // for (j...)
} // for (i...)
return NewImage;