邁向一萬小時成長之路

2013年9月10日星期二

如何把OpenGL ES的view做snapshot再轉成UIImage?

摘自https://developer.apple.com/library/ios/qa/qa1704/_index.html

Q: How do I take a snapshot of my OpenGL ES view and save the result in a UIImage?

// IMPORTANT: Call this method after you draw and before -presentRenderbuffer:.

- (UIImage*)snapshot:(UIView*)eaglview

{

    GLint backingWidth, backingHeight;

    // Bind the color renderbuffer used to render the OpenGL ES view

    // If your application only creates a single color renderbuffer which is already bound at this point,

    // this call is redundant, but it is needed if you're dealing with multiple renderbuffers.

    // Note, replace "_colorRenderbuffer" with the actual name of the renderbuffer object defined in your class.

    glBindRenderbufferOES(GL_RENDERBUFFER_OES, _colorRenderbuffer);

    // Get the size of the backing CAEAGLLayer

    glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth);

    glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight);

    NSInteger x = 0, y = 0, width = backingWidth, height = backingHeight;

    NSInteger dataLength = width * height * 4;

    GLubyte *data = (GLubyte*)malloc(dataLength * sizeof(GLubyte));

    // Read pixel data from the framebuffer

    glPixelStorei(GL_PACK_ALIGNMENT, 4);

    glReadPixels(x, y, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data);

    // Create a CGImage with the pixel data

    // If your OpenGL ES content is opaque, use kCGImageAlphaNoneSkipLast to ignore the alpha channel

    // otherwise, use kCGImageAlphaPremultipliedLast

    CGDataProviderRef ref = CGDataProviderCreateWithData(NULL, data, dataLength, NULL);

    CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();

    CGImageRef iref = CGImageCreate(width, height, 8, 32, width * 4, colorspace, kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedLast,

                                    ref, NULL, true, kCGRenderingIntentDefault);

    // OpenGL ES measures data in PIXELS

    // Create a graphics context with the target size measured in POINTS

    NSInteger widthInPoints, heightInPoints;

    if (NULL != UIGraphicsBeginImageContextWithOptions) {

        // On iOS 4 and later, use UIGraphicsBeginImageContextWithOptions to take the scale into consideration

        // Set the scale parameter to your OpenGL ES view's contentScaleFactor

        // so that you get a high-resolution snapshot when its value is greater than 1.0

        CGFloat scale = eaglview.contentScaleFactor;

        widthInPoints = width / scale;

        heightInPoints = height / scale;

        UIGraphicsBeginImageContextWithOptions(CGSizeMake(widthInPoints, heightInPoints), NO, scale);

    }

    else {

        // On iOS prior to 4, fall back to use UIGraphicsBeginImageContext

        widthInPoints = width;

        heightInPoints = height;

        UIGraphicsBeginImageContext(CGSizeMake(widthInPoints, heightInPoints));

    }

    CGContextRef cgcontext = UIGraphicsGetCurrentContext();

    // UIKit coordinate system is upside down to GL/Quartz coordinate system

    // Flip the CGImage by rendering it to the flipped bitmap context

    // The size of the destination area is measured in POINTS

    CGContextSetBlendMode(cgcontext, kCGBlendModeCopy);

    CGContextDrawImage(cgcontext, CGRectMake(0.0, 0.0, widthInPoints, heightInPoints), iref);

    // Retrieve the UIImage from the current context

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    // Clean up

    free(data);

    CFRelease(ref);

    CFRelease(colorspace);

    CGImageRelease(iref);

    return image;

}

2013年9月6日星期五

在NSDictionary中讀取和寫入CGRect

//讀取
CGRect newFrame = [[change objectForKey:@"new"]CGRectValue];

//寫入

dictionary = [NSDictionary dictionaryWithObjectsAndKeys:
    [NSValue valueWithCGRect:CGRectMake(100,100,200,200)],
    @"Crocodile",
    nil];

2013年9月5日星期四

objective-C中列舉(enum)的使用

第一種是原始的用法
.h檔
#import <Foundation/Foundation.h>
enum HHSlidaleViewModes{
    slideFromLeftToRight = 0,
    slideFromRightToLeft,
    rightSideFromCenter,
    leftSideFromCenter
};
@interface SlidableView : NSObject{
    enum HHSlidaleViewModes a;
}
.m檔
#import "SlidableView.h"
@implementation SlidableView
-(void)a{
    a = slideFromLeftToRight;
}
@end

第二種是通用的用法

首先，我們要先知道typedef是把型別名稱取一個別名
例如typedef int handsomeInt;
之後就可以宣告整數為 handsomeInt a = 100;

之後，我們就可以把上面的code改為：
.h檔
#import <Foundation/Foundation.h>
typedef enum HHSlidaleViewModes{
    slideFromLeftToRight = 0,
    slideFromRightToLeft,
    rightSideFromCenter,
    leftSideFromCenter
} hhSlidableViewModes;
@interface SlidableView : NSObject{
    hhSlidaleViewModes a;
}
.m檔
#import "SlidableView.h"
@implementation SlidableView
-(void)a{
    a = slideFromLeftToRight;
}
@end

//我自己的用法,利用typedef把後面的enum{running = 0,sleeping,header}改名為StepMode來使用

typedef enum{

    running = 0,

    sleeping,

    header

}StepMode;

2013年9月4日星期三

@selector傳遞參數

//呼叫不用參數的method

[self performSelector:@selector(fooNoInputs)];

//呼叫一個參數的method
[self performSelector:@selector(fooOneInput:) withObject:@"first"];

//呼叫二個參數的method
[self performSelector:@selector(fooFirstInput:secondInput:) withObject:@"first" withObject:@"second"];

刮刮樂的可刮部份

//
// ScratchableView.h
// CGScratch
//
// Created by Olivier Yiptong on 11-01-11.
// Copyright 2011 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface ScratchableView : UIView {
    float width;
    float height;
    CGPoint    location;
    CGPoint    previousLocation;
    BOOL firstTouch;
    CGImageRef scratchable;
    CGImageRef scratched;
    CGContextRef alphaPixels;
    CGDataProviderRef provider;
}

- (void) renderLineFromPoint:(CGPoint)start toPoint:(CGPoint)end;

@end

//
// ScratchableView.m
// CGScratch
//
// Created by Olivier Yiptong on 11-01-11.
// Copyright 2011 __MyCompanyName__. All rights reserved.
//

#import "ScratchableView.h"

@implementation ScratchableView

- (id)initWithFrame:(CGRect)frame {

    self = [super initWithFrame:frame];
    if (self) {
        //self.bounds = CGRectMake(0.0, 0.0, frame.size.width, frame.size.height);

        //自行把用來刮的scratch.png放入專案
        scratchable = [UIImage imageNamed:@"scratch.png"].CGImage;
//修改成隨bounds大小變化 by Harvey 20130903
//        width = CGImageGetWidth(scratchable);
//        height = CGImageGetHeight(scratchable);
        width = self.bounds.size.width;
        height = self.bounds.size.height;
        self.opaque = NO;
        CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceGray();

        CFMutableDataRef pixels = CFDataCreateMutable( NULL , width * height );
        alphaPixels = CGBitmapContextCreate( CFDataGetMutableBytePtr( pixels ) , width , height , 8 , width , colorspace , kCGImageAlphaNone );
        provider = CGDataProviderCreateWithCFData(pixels);


        CGContextSetFillColorWithColor(alphaPixels, [UIColor blackColor].CGColor);
        CGContextFillRect(alphaPixels, frame);

        CGContextSetStrokeColorWithColor(alphaPixels, [UIColor whiteColor].CGColor);
        CGContextSetLineWidth(alphaPixels, 20.0);
        CGContextSetLineCap(alphaPixels, kCGLineCapRound);

        //CGImageRef mask = CGImageMaskCreate(width, height, 8, 8, width, provider, nil, NO);
        CGImageRef mask = CGImageMaskCreate(width, height, 8, 8, width, provider, nil, NO);
        scratched = CGImageCreateWithMask(scratchable, mask);

        CGImageRelease(mask);
        CGColorSpaceRelease(colorspace);


    }
    return self;
}

- (void)drawRect:(CGRect)rect {
    CGContextDrawImage(UIGraphicsGetCurrentContext() , [self bounds] , scratched);
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [[event touchesForView:self] anyObject];
    firstTouch = YES;
    location = [touch locationInView:self];
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [[event touchesForView:self] anyObject];

    if (firstTouch) {
        firstTouch = NO;
        previousLocation = [touch previousLocationInView:self];
    } else {
        location = [touch locationInView:self];
        previousLocation = [touch previousLocationInView:self];
    }

    // Render the stroke
    [self renderLineFromPoint:previousLocation toPoint:location];
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [[event touchesForView:self] anyObject];
    if (firstTouch) {
        firstTouch = NO;
        previousLocation = [touch previousLocationInView:self];

        [self renderLineFromPoint:previousLocation toPoint:location];
    }
}

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

- (void) renderLineFromPoint:(CGPoint)start toPoint:(CGPoint)end {

    CGContextMoveToPoint(alphaPixels, start.x , start.y );
    CGContextAddLineToPoint(alphaPixels, end.x , end.y );
    CGContextStrokePath(alphaPixels);
    [self setNeedsDisplay];
}

- (void)dealloc {
    CGContextRelease(alphaPixels);
    CGImageRelease(scratchable);
    CGDataProviderRelease(provider);
    [super dealloc];
}

@end

NSZombieEnabled on Xcode 4.0(and up)

NSZombieEnabled只能在develop時使用，千萬別忘了在distrube時移掉，因為NSZombieEnabled不會真正釋放dealloc時的記憶體！

2013年9月2日星期一

使用drawRect繪圖

引用自http://blog.csdn.net/zhibudefeng/article/details/8463268

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
/*NO.1画一条线
CGContextSetRGBStrokeColor(context, 0.5, 0.5, 0.5, 0.5);//线条颜色
CGContextMoveToPoint(context, 20, 20);
CGContextAddLineToPoint(context, 200,20);
CGContextStrokePath(context);
*/
/*NO.2写文字
CGContextSetLineWidth(context, 1.0);
CGContextSetRGBFillColor (context, 0.5, 0.5, 0.5, 0.5);
UIFont *font = [UIFont boldSystemFontOfSize:18.0];
[@"公司：北京中软科技股份有限公司\n部门：ERP事业部\n姓名：McLiang" drawInRect:CGRectMake(20, 40, 280, 300) withFont:font];
*/
/*NO.3画一个正方形图形没有边框
CGContextSetRGBFillColor(context, 0, 0.25, 0, 0.5);
CGContextFillRect(context, CGRectMake(2, 2, 270, 270));
CGContextStrokePath(context);
*/
/*NO.4画正方形边框
CGContextSetRGBStrokeColor(context, 0.5, 0.5, 0.5, 0.5);//线条颜色
CGContextSetLineWidth(context, 2.0);
CGContextAddRect(context, CGRectMake(2, 2, 270, 270));
CGContextStrokePath(context);
*/
/*NO.5画方形背景颜色
CGContextTranslateCTM(context, 0.0f, self.bounds.size.height);
CGContextScaleCTM(context, 1.0f, -1.0f);
UIGraphicsPushContext(context);
CGContextSetLineWidth(context,320);
CGContextSetRGBStrokeColor(context, 250.0/255, 250.0/255, 210.0/255, 1.0);
CGContextStrokeRect(context, CGRectMake(0, 0, 320, 460));
UIGraphicsPopContext();
*/
/*NO.6椭圆
CGRect aRect= CGRectMake(80, 80, 160, 100);
CGContextSetRGBStrokeColor(context, 0.6, 0.9, 0, 1.0);
CGContextSetLineWidth(context, 3.0);
CGContextAddEllipseInRect(context, aRect); //椭圆
CGContextDrawPath(context, kCGPathStroke);
*/
/*NO.7
CGContextBeginPath(context);
CGContextSetRGBStrokeColor(context, 0, 0, 1, 1);
CGContextMoveToPoint(context, 100, 100);
CGContextAddArcToPoint(context, 50, 100, 50, 150, 50);
CGContextStrokePath(context);
*/
/*NO.8渐变
CGContextClip(context);
CGColorSpaceRef rgb = CGColorSpaceCreateDeviceRGB();
CGFloat colors[] =
{
204.0 / 255.0, 224.0 / 255.0, 244.0 / 255.0, 1.00,
29.0 / 255.0, 156.0 / 255.0, 215.0 / 255.0, 1.00,
0.0 / 255.0, 50.0 / 255.0, 126.0 / 255.0, 1.00,
};
CGGradientRef gradient = CGGradientCreateWithColorComponents
(rgb, colors, NULL, sizeof(colors)/(sizeof(colors[0])*4));
CGColorSpaceRelease(rgb);
CGContextDrawLinearGradient(context, gradient,CGPointMake
(0.0,0.0) ,CGPointMake(0.0,self.frame.size.height),
kCGGradientDrawsBeforeStartLocation);
*/
/* NO.9四条线画一个正方形
//画线
UIColor *aColor = [UIColor colorWithRed:0 green:1.0 blue:0 alpha:0];
CGContextSetRGBStrokeColor(context, 1.0, 0, 0, 1.0);
CGContextSetFillColorWithColor(context, aColor.CGColor);
CGContextSetLineWidth(context, 4.0);
CGPoint aPoints[5];
aPoints[0] =CGPointMake(60, 60);
aPoints[1] =CGPointMake(260, 60);
aPoints[2] =CGPointMake(260, 300);
aPoints[3] =CGPointMake(60, 300);
aPoints[4] =CGPointMake(60, 60);
CGContextAddLines(context, aPoints, 5);
CGContextDrawPath(context, kCGPathStroke); //开始画线
*/
/* NO.10
UIColor *aColor = [UIColor colorWithRed:0 green:1.0 blue:0 alpha:0];
CGContextSetRGBStrokeColor(context, 1.0, 0, 0, 1.0);
CGContextSetFillColorWithColor(context, aColor.CGColor);
//椭圆
CGRect aRect= CGRectMake(80, 80, 160, 100);
CGContextSetRGBStrokeColor(context, 0.6, 0.9, 0, 1.0);
CGContextSetLineWidth(context, 3.0);
CGContextSetFillColorWithColor(context, aColor.CGColor);
CGContextAddRect(context, rect); //矩形
CGContextAddEllipseInRect(context, aRect); //椭圆
CGContextDrawPath(context, kCGPathStroke);
*/
/* NO.11
画一个实心的圆
CGContextFillEllipseInRect(context, CGRectMake(95, 95, 100.0, 100));
*/
/*NO.12
画一个菱形
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 100, 100);
CGContextAddLineToPoint(context, 150, 150);
CGContextAddLineToPoint(context, 100, 200);
CGContextAddLineToPoint(context, 50, 150);
CGContextAddLineToPoint(context, 100, 100);
CGContextStrokePath(context);
*/
/*NO.13 画矩形
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGRect rectangle = CGRectMake(60,170,200,80);
CGContextAddRect(context, rectangle);
CGContextStrokePath(context);
*/
/*椭圆
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGRect rectangle = CGRectMake(60,170,200,80);
CGContextAddEllipseInRect(context, rectangle);
CGContextStrokePath(context);
*/
/*用红色填充了一段路径:
CGContextMoveToPoint(context, 100, 100);
CGContextAddLineToPoint(context, 150, 150);
CGContextAddLineToPoint(context, 100, 200);
CGContextAddLineToPoint(context, 50, 150);
CGContextAddLineToPoint(context, 100, 100);
CGContextSetFillColorWithColor(context, [UIColor redColor].CGColor);
CGContextFillPath(context);
*/
/*填充一个蓝色边的红色矩形
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGRect rectangle = CGRectMake(60,170,200,80);
CGContextAddRect(context, rectangle);
CGContextStrokePath(context);
CGContextSetFillColorWithColor(context, [UIColor redColor].CGColor);
CGContextFillRect(context, rectangle);
*/
/*画弧
//弧线的是通过指定两个切点，还有角度，调用CGContextAddArcToPoint()绘制
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 100, 100);
CGContextAddArcToPoint(context, 100,200, 300,200, 100);
CGContextStrokePath(context);
*/
/*
绘制贝兹曲线
//贝兹曲线是通过移动一个起始点，然后通过两个控制点,还有一个中止点，调用CGContextAddCurveToPoint() 函数绘制
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 10, 10);
CGContextAddCurveToPoint(context, 0, 50, 300, 250, 300, 400);
CGContextStrokePath(context);
*/
/*绘制二次贝兹曲线
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 10, 200);
CGContextAddQuadCurveToPoint(context, 150, 10, 300, 200);
CGContextStrokePath(context);
*/
/*绘制虚线
CGContextSetLineWidth(context, 5.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGFloat dashArray[] = {2,6,4,2};
CGContextSetLineDash(context, 3, dashArray, 4);//跳过3个再画虚线，所以刚开始有6-（3-2）=5个虚点
CGContextMoveToPoint(context, 10, 200);
CGContextAddQuadCurveToPoint(context, 150, 10, 300, 200);
CGContextStrokePath(context);
*/
/*绘制图片
NSString* imagePath = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage* myImageObj = [[UIImage alloc] initWithContentsOfFile:imagePath];
//[myImageObj drawAtPoint:CGPointMake(0, 0)];
[myImageObj drawInRect:CGRectMake(0, 0, 320, 480)];
NSString *s = @"我的小狗";
[s drawAtPoint:CGPointMake(100, 0) withFont:[UIFont systemFontOfSize:34.0]];
*/
/*
NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage *img = [UIImage imageWithContentsOfFile:path];
CGImageRef image = img.CGImage;
CGContextSaveGState(context);
CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);
CGContextDrawImage(context, touchRect, image);
CGContextRestoreGState(context);
*/
/*NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage *img = [UIImage imageWithContentsOfFile:path];
CGImageRef image = img.CGImage;
CGContextSaveGState(context);
CGContextRotateCTM(context, M_PI);
CGContextTranslateCTM(context, -img.size.width, -img.size.height);
CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);
CGContextDrawImage(context, touchRect, image);
CGContextRestoreGState(context);*/
/*
NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage *img = [UIImage imageWithContentsOfFile:path];
CGImageRef image = img.CGImage;
CGContextSaveGState(context);
CGAffineTransform myAffine = CGAffineTransformMakeRotation(M_PI);
myAffine = CGAffineTransformTranslate(myAffine, -img.size.width, -img.size.height);
CGContextConcatCTM(context, myAffine);
CGContextRotateCTM(context, M_PI);
CGContextTranslateCTM(context, -img.size.width, -img.size.height);
CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);
CGContextDrawImage(context, touchRect, image);
CGContextRestoreGState(context);
*/
}

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2013年9月10日 星期二

2013年9月6日 星期五

2013年9月5日 星期四

2013年9月4日 星期三

2013年9月2日 星期一

2013年9月10日星期二

2013年9月6日星期五

2013年9月5日星期四

2013年9月4日星期三

2013年9月2日星期一