mrmBot-Matrix/natives/flip.cc

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#include <map>
#include <vips/vips8>
#include "common.h"
using namespace std;
using namespace vips;
ArgumentMap Flip(string type, string *outType, char *BufferData, size_t BufferLength,
ArgumentMap Arguments, size_t *DataSize) {
bool flop = GetArgumentWithFallback<bool>(Arguments, "flop", false);
VImage in = VImage::new_from_buffer(BufferData, BufferLength, "",
type == "gif"
? VImage::option()->set("n", -1)->set(
"access", "sequential")
: 0)
.colourspace(VIPS_INTERPRETATION_sRGB);
if (!in.has_alpha()) in = in.bandjoin(255);
VImage out;
if (flop) {
out = in.flip(VIPS_DIRECTION_HORIZONTAL);
} else if (type == "gif") {
// libvips gif handling is both a blessing and a curse
vector<VImage> img;
int pageHeight = vips_image_get_page_height(in.get_image());
int nPages = vips_image_get_n_pages(in.get_image());
for (int i = 0; i < nPages; i++) {
VImage img_frame = in.crop(0, i * pageHeight, in.width(), pageHeight);
VImage flipped = img_frame.flip(VIPS_DIRECTION_VERTICAL);
img.push_back(flipped);
}
out = VImage::arrayjoin(img, VImage::option()->set("across", 1));
out.set(VIPS_META_PAGE_HEIGHT, pageHeight);
} else {
out = in.flip(VIPS_DIRECTION_VERTICAL);
}
void *buf;
out.write_to_buffer(
("." + *outType).c_str(), &buf, DataSize,
*outType == "gif"
? VImage::option()->set("dither", 0)->set("reoptimise", 1)
: 0);
ArgumentMap output;
output["buf"] = (char *)buf;
output["width"] = out.width();
output["height"] = vips_image_get_page_height(in.get_image());
return output;
}