Mathis/sharp
1
0
Fork 0
mirror of https://github.com/lovell/sharp.git synced 2026-02-04 21:56:18 +01:00
Code Issues Packages Projects Releases Wiki Activity

Add top/left offset support to overlayWith operation (#473)

Browse Source
This commit is contained in:
Rahul Nanwani
2016-07-05 14:42:02 +05:30
committed by Lovell Fuller
parent a5d85b8a54
commit 278273b5c3
15 changed files with 338 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

59
src/operations.cc
View File

@@ -16,6 +16,49 @@ namespace sharp {
Assumes alpha channels are already premultiplied and will be unpremultiplied after.
*/
VImage Composite(VImage src, VImage dst, const int gravity) {
if(IsInputValidForComposition(src, dst)) {
// Enlarge overlay src, if required
if (src.width() < dst.width() || src.height() < dst.height()) {
// Calculate the (left, top) coordinates of the output image within the input image, applying the given gravity.
int left;
int top;
std::tie(left, top) = CalculateCrop(dst.width(), dst.height(), src.width(), src.height(), gravity);
// Embed onto transparent background
std::vector<double> background { 0.0, 0.0, 0.0, 0.0 };
src = src.embed(left, top, dst.width(), dst.height(), VImage::option()
->set("extend", VIPS_EXTEND_BACKGROUND)
->set("background", background)
);
}
return CompositeImage(src, dst);
}
// If the input was not valid for composition the return the input image itself
return dst;
}
VImage Composite(VImage src, VImage dst, const int x, const int y) {
if(IsInputValidForComposition(src, dst)) {
// Enlarge overlay src, if required
if (src.width() < dst.width() || src.height() < dst.height()) {
// Calculate the (left, top) coordinates of the output image within the input image, applying the given gravity.
int left;
int top;
std::tie(left, top) = CalculateCrop(dst.width(), dst.height(), src.width(), src.height(), x, y);
// Embed onto transparent background
std::vector<double> background { 0.0, 0.0, 0.0, 0.0 };
src = src.embed(left, top, dst.width(), dst.height(), VImage::option()
->set("extend", VIPS_EXTEND_BACKGROUND)
->set("background", background)
);
}
return CompositeImage(src, dst);
}
// If the input was not valid for composition the return the input image itself
return dst;
}
bool IsInputValidForComposition(VImage src, VImage dst) {
using sharp::CalculateCrop;
using sharp::HasAlpha;
@@ -29,20 +72,10 @@ namespace sharp {
throw VError("Overlay image must have same dimensions or smaller");
}
// Enlarge overlay src, if required
if (src.width() < dst.width() || src.height() < dst.height()) {
// Calculate the (left, top) coordinates of the output image within the input image, applying the given gravity.
int left;
int top;
std::tie(left, top) = CalculateCrop(dst.width(), dst.height(), src.width(), src.height(), gravity);
// Embed onto transparent background
std::vector<double> background { 0.0, 0.0, 0.0, 0.0 };
src = src.embed(left, top, dst.width(), dst.height(), VImage::option()
->set("extend", VIPS_EXTEND_BACKGROUND)
->set("background", background)
);
}
return true;
}
VImage CompositeImage(VImage src, VImage dst) {
// Split src into non-alpha and alpha channels
VImage srcWithoutAlpha = src.extract_band(0, VImage::option()->set("n", src.bands() - 1));
VImage srcAlpha = src[src.bands() - 1] * (1.0 / 255.0);