Alien-FreeImage
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src/Source/FreeImageToolkit/Background.cpp view on Meta::CPAN
// for palettized images only
return result;
}
if (options & FI_COLOR_FIND_EQUAL_COLOR) {
// Option FI_COLOR_ALPHA_IS_INDEX is implicit here so, set
// index to color->rgbReserved
result = color->rgbReserved;
if (bpp == 1) {
result &= 0x01;
} else if (bpp == 4) {
result &= 0x0F;
}
unsigned ucolor;
if (!IsVisualGreyscaleImage(dib)) {
ucolor = (*((unsigned *)color)) & 0xFFFFFF;
} else {
ucolor = GREY(color->rgbRed, color->rgbGreen, color->rgbBlue) * 0x010101;
//ucolor = (ucolor | (ucolor << 8) | (ucolor << 16));
}
unsigned ncolors = FreeImage_GetColorsUsed(dib);
unsigned *palette = (unsigned *)FreeImage_GetPalette(dib);
for (unsigned i = 0; i < ncolors; i++) {
if ((palette[i] & 0xFFFFFF) == ucolor) {
result = i;
break;
}
}
} else {
unsigned minimum = UINT_MAX;
unsigned ncolors = FreeImage_GetColorsUsed(dib);
BYTE *palette = (BYTE *)FreeImage_GetPalette(dib);
BYTE red, green, blue;
if (!IsVisualGreyscaleImage(dib)) {
red = color->rgbRed;
green = color->rgbGreen;
blue = color->rgbBlue;
} else {
red = GREY(color->rgbRed, color->rgbGreen, color->rgbBlue);
green = blue = red;
}
for (unsigned i = 0; i < ncolors; i++) {
unsigned m = abs(palette[FI_RGBA_BLUE] - blue)
+ abs(palette[FI_RGBA_GREEN] - green)
+ abs(palette[FI_RGBA_RED] - red);
if (m < minimum) {
minimum = m;
result = i;
if (m == 0) {
break;
}
}
palette += sizeof(RGBQUAD);
}
}
return result;
}
/** @brief Blends an alpha-transparent foreground color over an opaque background
color.
This function blends the alpha-transparent foreground color fgcolor over the
background color bgcolor. The background color is considered fully opaque,
whatever it's alpha value contains, whereas the foreground color is considered
to be a real RGBA color with an alpha value, which is used for the blend
operation. The resulting color is returned through the blended parameter.
@param bgcolor The background color for the blend operation.
@param fgcolor The foreground color for the blend operation. This color's alpha
value, stored in the rgbReserved member, is the alpha value used for the blend
operation.
@param blended This out parameter takes the blended color and so, returns it to
the caller. This color's alpha value will be 0xFF (255) so, the blended color
itself has no transparency. The this argument is not changed, if the function
fails.
@return Returns TRUE on success, FALSE otherwise. This function fails if any of
the color arguments is a null pointer.
*/
static BOOL
GetAlphaBlendedColor(const RGBQUAD *bgcolor, const RGBQUAD *fgcolor, RGBQUAD *blended) {
if ((!bgcolor) || (!fgcolor) || (!blended)) {
return FALSE;
}
BYTE alpha = fgcolor->rgbReserved;
BYTE not_alpha = ~alpha;
blended->rgbRed = (BYTE)( ((WORD)fgcolor->rgbRed * alpha + not_alpha * (WORD)bgcolor->rgbRed) >> 8 );
blended->rgbGreen = (BYTE)( ((WORD)fgcolor->rgbGreen * alpha + not_alpha * (WORD)bgcolor->rgbGreen) >> 8) ;
blended->rgbBlue = (BYTE)( ((WORD)fgcolor->rgbRed * alpha + not_alpha * (WORD)bgcolor->rgbBlue) >> 8 );
blended->rgbReserved = 0xFF;
return TRUE;
}
/** @brief Fills a FIT_BITMAP image with the specified color.
This function does the dirty work for FreeImage_FillBackground for FIT_BITMAP
images.
@param dib The image to be filled.
@param color The color, the specified image should be filled with.
@param options Options that affect the color search process for palletized images.
@return Returns TRUE on success, FALSE otherwise. This function fails if any of
the dib and color is NULL or the provided image is not a FIT_BITMAP image.
*/
static BOOL
FillBackgroundBitmap(FIBITMAP *dib, const RGBQUAD *color, int options) {
if ((!dib) || (FreeImage_GetImageType(dib) != FIT_BITMAP)) {
return FALSE;;
}
if (!color) {
return FALSE;
}
const RGBQUAD *color_intl = color;
unsigned bpp = FreeImage_GetBPP(dib);
unsigned width = FreeImage_GetWidth(dib);
unsigned height = FreeImage_GetHeight(dib);
FREE_IMAGE_COLOR_TYPE color_type = FreeImage_GetColorType(dib);
// get a pointer to the first scanline (bottom line)
BYTE *src_bits = FreeImage_GetScanLine(dib, 0);
BYTE *dst_bits = src_bits;
BOOL supports_alpha = ((bpp >= 24) || ((bpp == 8) && (color_type != FIC_PALETTE)));
// Check for RGBA case if bitmap supports alpha
// blending (8-bit greyscale, 24- or 32-bit images)
if (supports_alpha && (options & FI_COLOR_IS_RGBA_COLOR)) {
if (color->rgbReserved == 0) {
// the fill color is fully transparent; we are done
return TRUE;
}
// Only if the fill color is NOT fully opaque, draw it with
// the (much) slower FreeImage_DrawLine function and return.
// Since we do not have the FreeImage_DrawLine function in this
// release, just assume to have an unicolor background and fill
// all with an 'alpha-blended' color.
if (color->rgbReserved < 255) {
// If we will draw on an unicolor background, it's
// faster to draw opaque with an alpha blended color.
// So, first get the color from the first pixel in the
// image (bottom-left pixel).
RGBQUAD bgcolor;
if (bpp == 8) {
bgcolor = FreeImage_GetPalette(dib)[*src_bits];
} else {
bgcolor.rgbBlue = src_bits[FI_RGBA_BLUE];
bgcolor.rgbGreen = src_bits[FI_RGBA_GREEN];
bgcolor.rgbRed = src_bits[FI_RGBA_RED];
bgcolor.rgbReserved = 0xFF;
}
RGBQUAD blend;
GetAlphaBlendedColor(&bgcolor, color_intl, &blend);
color_intl = &blend;
}
}
int index = (bpp <= 8) ? GetPaletteIndex(dib, color_intl, options, &color_type) : 0;
if (index == -1) {
// No palette index found for a palletized
// image. This should never happen...
return FALSE;
}
// first, build the first scanline (line 0)
switch (bpp) {
case 1: {
unsigned bytes = (width / 8);
memset(dst_bits, ((index == 1) ? 0xFF : 0x00), bytes);
//int n = width % 8;
int n = width & 7;
if (n) {
if (index == 1) {
// set n leftmost bits
dst_bits[bytes] |= (0xFF << (8 - n));
} else {
// clear n leftmost bits
dst_bits[bytes] &= (0xFF >> n);
}
}
break;
}
case 4: {
unsigned bytes = (width / 2);
memset(dst_bits, (index | (index << 4)), bytes);
//if (bytes % 2) {
if (bytes & 1) {
dst_bits[bytes] &= 0x0F;
src/Source/FreeImageToolkit/Background.cpp view on Meta::CPAN
case 16: {
WORD wcolor = RGBQUAD_TO_WORD(dib, color_intl);
for (unsigned x = 0; x < width; x++) {
((WORD *)dst_bits)[x] = wcolor;
}
break;
}
case 24: {
RGBTRIPLE rgbt = *((RGBTRIPLE *)color_intl);
for (unsigned x = 0; x < width; x++) {
((RGBTRIPLE *)dst_bits)[x] = rgbt;
}
break;
}
case 32: {
RGBQUAD rgbq;
rgbq.rgbBlue = ((RGBTRIPLE *)color_intl)->rgbtBlue;
rgbq.rgbGreen = ((RGBTRIPLE *)color_intl)->rgbtGreen;
rgbq.rgbRed = ((RGBTRIPLE *)color_intl)->rgbtRed;
rgbq.rgbReserved = 0xFF;
for (unsigned x = 0; x < width; x++) {
((RGBQUAD *)dst_bits)[x] = rgbq;
}
break;
}
default:
return FALSE;
}
// Then, copy the first scanline into all following scanlines.
// 'src_bits' is a pointer to the first scanline and is already
// set up correctly.
if (src_bits) {
unsigned pitch = FreeImage_GetPitch(dib);
unsigned bytes = FreeImage_GetLine(dib);
dst_bits = src_bits + pitch;
for (unsigned y = 1; y < height; y++) {
memcpy(dst_bits, src_bits, bytes);
dst_bits += pitch;
}
}
return TRUE;
}
/** @brief Fills an image with the specified color.
This function sets all pixels of an image to the color provided through the color
parameter. Since this should work for all image types supported by FreeImage, the
pointer color must point to a memory location, which is at least as large as the
image's color value, if this size is greater than 4 bytes. As the color is specified
by an RGBQUAD structure for all images of type FIT_BITMAP (including all palletized
images), the smallest possible size of this memory is the size of the RGBQUAD structure,
which uses 4 bytes.
So, color must point to a double, if the image to be filled is of type FIT_DOUBLE and
point to a RGBF structure if the image is of type FIT_RGBF and so on.
However, the fill color is always specified through a RGBQUAD structure for all images
of type FIT_BITMAP. So, for 32- and 24-bit images, the red, green and blue members of
the RGBQUAD structure are directly used for the image's red, green and blue channel
respectively. Although alpha transparent RGBQUAD colors are supported, the alpha channel
of a 32-bit image never gets modified by this function. A fill color with an alpha value
smaller than 255 gets blended with the image's actual background color, which is determined
from the image's bottom-left pixel. So, currently using alpha enabled colors, assumes the
image to be unicolor before the fill operation. However, the RGBQUAD's rgbReserved member is
only taken into account, if option FI_COLOR_IS_RGBA_COLOR has been specified.
For 16-bit images, the red-, green- and blue components of the specified color are
transparently translated into either the 16-bit 555 or 565 representation. This depends
on the image's actual red- green- and blue masks.
Special attention must be payed for palletized images. Generally, the RGB color specified
is looked up in the image's palette. The found palette index is then used to fill the image.
There are some option flags, that affect this lookup process:
no option specified (0x00) Uses the color, that is nearest to the specified color.
This is the default behavior and should always find a
color in the palette. However, the visual result may
far from what was expected and mainly depends on the
image's palette.
FI_COLOR_FIND_EQUAL_COLOR (0x02) Searches the image's palette for the specified color
but only uses the returned palette index, if the specified
color exactly matches the palette entry. Of course,
depending on the image's actual palette entries, this
operation may fail. In this case, the function falls back
to option FI_COLOR_ALPHA_IS_INDEX and uses the RGBQUAD's
rgbReserved member (or its low nibble for 4-bit images
or its least significant bit (LSB) for 1-bit images) as
the palette index used for the fill operation.
FI_COLOR_ALPHA_IS_INDEX (0x04) Does not perform any color lookup from the palette, but
uses the RGBQUAD's alpha channel member rgbReserved as
the palette index to be used for the fill operation.
However, for 4-bit images, only the low nibble of the
rgbReserved member are used and for 1-bit images, only
the least significant bit (LSB) is used.
This function fails if any of dib and color is NULL.
@param dib The image to be filled.
@param color A pointer to the color value to be used for filling the image. The
memory pointed to by this pointer is always assumed to be at least as large as the
image's color value, but never smaller than the size of an RGBQUAD structure.
@param options Options that affect the color search process for palletized images.
@return Returns TRUE on success, FALSE otherwise. This function fails if any of
dib and color is NULL.
*/
BOOL DLL_CALLCONV
FreeImage_FillBackground(FIBITMAP *dib, const void *color, int options) {
if (!FreeImage_HasPixels(dib)) {
return FALSE;
}
if (!color) {
return FALSE;
}
// handle FIT_BITMAP images with FreeImage_FillBackground()
if (FreeImage_GetImageType(dib) == FIT_BITMAP) {
return FillBackgroundBitmap(dib, (RGBQUAD *)color, options);
}
// first, construct the first scanline (bottom line)
unsigned bytespp = (FreeImage_GetBPP(dib) / 8);
BYTE *src_bits = FreeImage_GetScanLine(dib, 0);
BYTE *dst_bits = src_bits;
for (unsigned x = 0; x < FreeImage_GetWidth(dib); x++) {
src/Source/FreeImageToolkit/Background.cpp view on Meta::CPAN
image. In other words, this function does not support partial palettes.
However, specifying a palette is not necessarily needed, even for palletized images. This
function is capable of implicitly creating a palette, if parameter palette is NULL. If the
specified background color is a greyscale value (red = green = blue) or if option
FI_COLOR_ALPHA_IS_INDEX is specified, a greyscale palette is created. For a 1-bit image, only
if the specified background color is either black or white, a monochrome palette, consisting
of black and white only is created. In any case, the darker colors are stored at the smaller
palette indices.
If the specified background color is not a greyscale value, or is neither black nor white
for a 1-bit image, solely this single color is injected into the otherwise black-initialized
palette. For this operation, option FI_COLOR_ALPHA_IS_INDEX is implicit, so the specified
color is applied to the palette entry, specified by the background color's rgbReserved
member. The image is then filled with this palette index.
This function returns a newly created image as function FreeImage_Allocate does, if both
parameters color and palette are NULL. If only color is NULL, the palette pointed to by
parameter palette is initially set for the new image, if a palletized image of type
FIT_BITMAP is created. However, in the latter case, this function returns an image, whose
pixels are all initialized with zeros so, the image will be filled with the color of the
first palette entry.
@param width The desired width in pixels of the new image.
@param height The desired height in pixels of the new image.
@param bpp The desired bit depth of the new image.
@param color A pointer to an RGBQUAD structure, that provides the color to be used for
filling the image.
@param options Options that affect the color search process for palletized images.
@param red_mask Specifies the bits used to store the red components of a pixel.
@param green_mask Specifies the bits used to store the green components of a pixel.
@param blue_mask Specifies the bits used to store the blue components of a pixel.
@return Returns a pointer to a newly allocated image on success, NULL otherwise.
*/
FIBITMAP * DLL_CALLCONV
FreeImage_AllocateEx(int width, int height, int bpp, const RGBQUAD *color, int options, const RGBQUAD *palette, unsigned red_mask, unsigned green_mask, unsigned blue_mask) {
return FreeImage_AllocateExT(FIT_BITMAP, width, height, bpp, ((void *)color), options, palette, red_mask, green_mask, blue_mask);
}
/** @brief Enlarges or shrinks an image selectively per side and fills newly added areas
with the specified background color.
This function enlarges or shrinks an image selectively per side. The main purpose of this
function is to add borders to an image. To add a border to any of the image's sides, a
positive integer value must be passed in any of the parameters left, top, right or bottom.
This value represents the border's width in pixels. Newly created parts of the image (the
border areas) are filled with the specified color. Specifying a negative integer value for
a certain side, will shrink or crop the image on this side. Consequently, specifying zero
for a certain side will not change the image's extension on that side.
So, calling this function with all parameters left, top, right and bottom set to zero, is
effectively the same as calling function FreeImage_Clone; setting all parameters left, top,
right and bottom to value equal to or smaller than zero, my easily be substituted by a call
to function FreeImage_Copy. Both these cases produce a new image, which is guaranteed not to
be larger than the input image. Thus, since the specified color is not needed in these cases,
the pointer color may be NULL.
Both parameters color and options work according to function FreeImage_FillBackground. So,
please refer to the documentation of FreeImage_FillBackground to learn more about parameters
color and options. For palletized images, the palette of the input image src is
transparently copied to the newly created enlarged or shrunken image, so any color
look-ups are performed on this palette.
Here are some examples, that illustrate, how to use the parameters left, top, right and
bottom:
// create a white color
RGBQUAD c;
c.rgbRed = 0xFF;
c.rgbGreen = 0xFF;
c.rgbBlue = 0xFF;
c.rgbReserved = 0x00;
// add a white, symmetric 10 pixel wide border to the image
dib2 = FreeImage_EnlargeCanvas(dib, 10, 10, 10, 10, &c, FI_COLOR_IS_RGB_COLOR);
// add white, 20 pixel wide stripes to the top and bottom side of the image
dib3 = FreeImage_EnlargeCanvas(dib, 0, 20, 0, 20, &c, FI_COLOR_IS_RGB_COLOR);
// add white, 30 pixel wide stripes to the right side of the image and
// cut off the 40 leftmost pixel columns
dib3 = FreeImage_EnlargeCanvas(dib, -40, 0, 30, 0, &c, FI_COLOR_IS_RGB_COLOR);
This function fails if either the input image is NULL or the pointer to the color is
NULL, while at least on of left, top, right and bottom is greater than zero. This
function also returns NULL, if the new image's size will be negative in either x- or
y-direction.
@param dib The image to be enlarged or shrunken.
@param left The number of pixels, the image should be enlarged on its left side. Negative
values shrink the image on its left side.
@param top The number of pixels, the image should be enlarged on its top side. Negative
values shrink the image on its top side.
@param right The number of pixels, the image should be enlarged on its right side. Negative
values shrink the image on its right side.
@param bottom The number of pixels, the image should be enlarged on its bottom side. Negative
values shrink the image on its bottom side.
@param color The color, the enlarged sides of the image should be filled with.
@param options Options that affect the color search process for palletized images.
@return Returns a pointer to a newly allocated enlarged or shrunken image on success,
NULL otherwise. This function fails if either the input image is NULL or the pointer to the
color is NULL, while at least on of left, top, right and bottom is greater than zero. This
function also returns NULL, if the new image's size will be negative in either x- or
y-direction.
*/
FIBITMAP * DLL_CALLCONV
FreeImage_EnlargeCanvas(FIBITMAP *src, int left, int top, int right, int bottom, const void *color, int options) {
if(!FreeImage_HasPixels(src)) return NULL;
// Just return a clone of the image, if left, top, right and bottom are
// all zero.
if ((left == 0) && (right == 0) && (top == 0) && (bottom == 0)) {
return FreeImage_Clone(src);
}
int width = FreeImage_GetWidth(src);
int height = FreeImage_GetHeight(src);
// Relay on FreeImage_Copy, if all parameters left, top, right and
// bottom are smaller than or equal zero. The color pointer may be
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