Working with Raw Pixels

C4WorkSpace.m

//
// C4WorkSpace.m
//
// Created by Travis Kirton
//

#import "C4WorkSpace.h"

@implementation C4WorkSpace

-(void)setup {
    [self getRawPixelsAndCreateImages];
}

-(void)getRawPixelsAndCreateImages {
    C4Image *image      = [C4Image imageNamed:@"C4Table.png"];

    NSUInteger width = CGImageGetWidth(image.CGImage);
    NSUInteger height = CGImageGetHeight(image.CGImage);
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    
    NSUInteger bytesPerPixel = 4;
    NSUInteger bytesPerRow = bytesPerPixel * width;
    unsigned char *rawData = malloc(height * bytesPerRow);
    
    NSUInteger bitsPerComponent = 8;
    CGContextRef context = CGBitmapContextCreate(rawData, width, height, bitsPerComponent, bytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
    CGColorSpaceRelease(colorSpace);
    CGContextDrawImage(context, CGRectMake(0, 0, width, height), image.CGImage);
    CGContextRelease(context);
    
    C4Image *imgimgimg = [[C4Image alloc] initWithRawData:rawData width:width height:height];
    [self.canvas addImage:imgimgimg];
    
    for(int i = 0; i < height * bytesPerRow; i += 4) {
        rawData[i] = 255;
    }

    C4Image *redImgimgimg = [[C4Image alloc] initWithRawData:rawData width:width height:height];
    redImgimgimg.origin = CGPointMake(0,320);
    [self.canvas addImage:redImgimgimg];
}

@end