iOS 커스텀 뷰에 메모리 비트맵 그리기

#import <UIKit/UIKit.h>

@interface RenderView : UIView

{

    CGImageRef imageRef;

    char *rawData;

int rb, w, h;

    CGColorSpaceRef colorSpace;

}

 

@end

#import "RenderView.h"

@implementation RenderView

- (id)initWithCoder:(NSCoder *)aDecoder {

    self = [super initWithCoder:aDecoder];

    NSLog(@"initWithCoder");

    

    colorSpace = CGColorSpaceCreateDeviceRGB();

    

    w = self.bounds.size.width;

    h = self.bounds.size.height;

    rb = 4*w;

    

    NSLog(@"w=%i h=%i", w, h);

    rawData = (char*)malloc(h * rb);

    for(int i=0; i<h; i++) {

        for(int j=0; j<w; j++) {

            rawData[rb*i + 4*j+0] = 255;//A

            rawData[rb*i + 4*j+1] = 0;

            rawData[rb*i + 4*j+2] = 0;

            rawData[rb*i + 4*j+3] = 255;//R

        }

    }

    return self;

}

// Only override drawRect: if you perform custom drawing.

// An empty implementation adversely affects performance during animation.

- (void)drawRect:(CGRect)rect

{

    [super drawRect:rect];

    // Drawing code

    NSLog(@"RenderView.drawRect");

    

    // 빨간 사각형을 그려보자

    CGContextRef context = UIGraphicsGetCurrentContext();

  

    // 픽셀을 입력하자

    CGContextRef ctx = CGBitmapContextCreate(rawData,w,h, 8,

                                             rb,

                                             colorSpace,

                                             kCGImageAlphaPremultipliedLast

                                             );

    imageRef = CGBitmapContextCreateImage(ctx);

    CGContextRelease(ctx);

    

    // 그리자 이제

    CGContextDrawImage(context, CGRectMake(0,0,w,h), imageRef);

}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    

}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {

    

}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

    

}

@end