marseymoji/third_party/pngquant/rwpng_cocoa.m

76 lines
2.2 KiB
Objective-C

//
// rwpng_cocoa.m
// pngquant
//
#include "rwpng.h"
#ifdef USE_COCOA
#import <Cocoa/Cocoa.h>
#import <CoreGraphics/CoreGraphics.h>
#include <stdio.h>
#include "lib/libimagequant.h"
#include "lib/pam.h"
int rwpng_read_image24_cocoa(FILE *fp, png24_image *out)
{
rgba_pixel *pixel_data;
int width, height;
@autoreleasepool {
NSFileHandle *fh = [[NSFileHandle alloc] initWithFileDescriptor:fileno(fp)];
NSData *data = [fh readDataToEndOfFile];
out->file_size = [data length];
CGImageRef image = [[NSBitmapImageRep imageRepWithData:data] CGImage];
[fh release];
if (!image) return READ_ERROR;
width = CGImageGetWidth(image);
height = CGImageGetHeight(image);
pixel_data = calloc(width*height,4);
CGColorSpaceRef colorspace = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
CGContextRef context = CGBitmapContextCreate(pixel_data,
width, height,
8, width*4,
colorspace,
(CGBitmapInfo)kCGImageAlphaPremultipliedLast);
CGColorSpaceRelease(colorspace);
if (!context) return READ_ERROR;
CGContextDrawImage(context, CGRectMake(0.0, 0.0, width, height), image);
CGContextRelease(context);
}
// reverse premultiplication
for(int i=0; i < width*height; i++) {
if (pixel_data[i].a) {
pixel_data[i] = (rgba_pixel){
.a = pixel_data[i].a,
.r = pixel_data[i].r*255/pixel_data[i].a,
.g = pixel_data[i].g*255/pixel_data[i].a,
.b = pixel_data[i].b*255/pixel_data[i].a,
};
}
}
out->gamma = 0.45455;
out->input_color = RWPNG_COCOA;
out->output_color = RWPNG_SRGB;
out->width = width;
out->height = height;
out->rgba_data = (unsigned char *)pixel_data;
out->row_pointers = malloc(sizeof(out->row_pointers[0])*out->height);
for(int i=0; i < out->height; i++) {
out->row_pointers[i] = (unsigned char *)&pixel_data[width*i];
}
return SUCCESS;
}
#endif