/*

File: ViewController.m

Abstract:

Version: 1.2

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*/

#import "ViewController.h"

#import "EAGLView.h"

#define DEG2RAD (M_PI/180.0f)

// These enums match the button tags in the nib

enum {

BUTTON_BRIGHTNESS,

BUTTON_CONTRAST,

BUTTON_SATURATION,

BUTTON_HUE,

BUTTON_SHARPNESS,

NUM_BUTTONS

};

@implementation ViewController

@synthesize slider;

@synthesize tabBar;

- (void)viewDidLoad

{

int b, i;

// Select first tab by default

tabBar.selectedItem = [tabBar.items objectAtIndex:0];

// Create a bitmap context for rendering the tabBar buttons

// Usually, button images are loaded from disk, but these simple shapes can be procedurally generated.

// UITabBar only needs the alpha channel of these images.

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

CGContextRef context = CGBitmapContextCreate(nil, 30, 30, 8, 0, colorSpace, kCGImageAlphaPremultipliedFirst);

CGImageRef theCGImage;

// Draw with white round strokes

CGContextSetLineCap(context, kCGLineCapRound);

CGContextSetRGBStrokeColor(context, 1.0, 1.0, 1.0, 1.0);

CGContextSetRGBFillColor(context, 1.0, 1.0, 1.0, 1.0);

CGContextSetLineWidth(context, 2.0);

for (b = 0; b < NUM_BUTTONS; b++)

{

CGContextClearRect(context, CGRectMake(0, 0, 30, 30));

switch(b)

{

case BUTTON_BRIGHTNESS:

{

const CGFloat line[8*4] = {

15.0, 6.0, 15.0, 4.0,

15.0,24.0, 15.0,26.0,

6.0,15.0, 4.0,15.0,

24.0,15.0, 26.0,15.0,

21.5,21.5, 23.0,23.0,

8.5, 8.5, 7.0, 7.0,

21.5, 8.5, 23.0, 7.0,

8.5,21.5, 7.0,23.0,

};

// A circle with eight rays around it

CGContextStrokeEllipseInRect(context, CGRectMake(10.5, 10.5, 9.0, 9.0));

for (i = 0; i < 8; i++)

{

CGContextMoveToPoint(context, line[i*4+0], line[i*4+1]);

CGContextAddLineToPoint(context, line[i*4+2], line[i*4+3]);

CGContextStrokePath(context);

}

break;

}

case BUTTON_CONTRAST:

{

// A circle with the right half filled

CGContextStrokeEllipseInRect(context, CGRectMake(4.0, 4.0, 22.0, 22.0));

CGContextAddArc(context, 15.0, 15.0, 11.0, -M_PI/2.0, M_PI/2.0, false);

CGContextFillPath(context);

break;

}

case BUTTON_SATURATION:

{

CGGradientRef gradient;

const CGFloat stripe[3][12] = {

{ 0.3,0.3,0.3,0.15, 1.0,0.0,0.0,0.70, 5, 5, 7, 25 },

{ 0.5,0.5,0.5,0.25, 0.0,1.0,0.0,0.75, 12, 5, 6, 25 },

{ 0.2,0.2,0.2,0.10, 0.0,0.0,1.0,0.65, 18, 5, 7, 25 },

};

// Red/Green/Blue gradients, inside a rounded rect

for (i = 0; i < 3; i++)

{

gradient = CGGradientCreateWithColorComponents(colorSpace, stripe[i], NULL, 2);

CGContextSaveGState(context);

CGContextClipToRect(context, CGRectMake(stripe[i][8], stripe[i][9], stripe[i][10], stripe[i][11]));

CGContextDrawLinearGradient(context, gradient, CGPointMake(15, 5), CGPointMake(15, 25), 0);

CGContextRestoreGState(context);

CGGradientRelease(gradient);

}

CGContextMoveToPoint(context, 4, 15);

CGContextAddArcToPoint(context, 4, 4, 15, 4, 4);

CGContextAddArcToPoint(context, 26, 4, 26, 15, 4);

CGContextAddArcToPoint(context, 26, 26, 15, 26, 4);

CGContextAddArcToPoint(context, 4, 26, 4, 15, 4);

CGContextClosePath(context);

CGContextStrokePath(context);

break;

}

case BUTTON_HUE:

{

CGGradientRef gradient;

CGFloat hue[8];

const int angle = 4;

// A radial gradient, inside a circle

for (i = 0; i < 360; i+=angle)

{

float x = cosf((i+angle*0.5)*DEG2RAD)*10+15;

float y = sinf((i+angle*0.5)*DEG2RAD)*10+15;

float r = (i )/180.0; if (r > 1.0) r = 2.0-r;

float g = (i+120)/180.0; if (g > 2.0) g = g-2.0; else if (g > 1.0) g = 2.0-g;

float b = (i+240)/180.0; if (b > 3.0) b = 4.0-b; else if (b > 2.0) b = b-2.0; else b = 2.0-b;

float a = (i+ 90)/180.0; if (a > 2.0) a = a-2.0; else if (a > 1.0) a = 2.0-a;

hue[0] = hue[4] = r;

hue[1] = hue[5] = g;

hue[2] = hue[6] = b;

hue[3] = a*0.5;

hue[7] = a*0.75;

gradient = CGGradientCreateWithColorComponents(colorSpace, hue, NULL, 2);

CGContextSaveGState(context);

CGContextMoveToPoint(context, 15, 15);

CGContextAddArc(context, 15, 15, 10, i*DEG2RAD, (i+angle)*DEG2RAD, false);

CGContextClosePath(context);

CGContextClip(context);

CGContextDrawLinearGradient(context, gradient, CGPointMake(x, y), CGPointMake(15, 15), 0);

CGContextRestoreGState(context);

CGGradientRelease(gradient);

}

CGContextStrokeEllipseInRect(context, CGRectMake(4.0, 4.0, 22.0, 22.0));

break;

}

case BUTTON_SHARPNESS:

{

int x, y;

// A gradient checkerboard, inside a rounded rect

for (x = 5; x < 25; x+=2)

{

float b = (x - 5)/19.0*0.5+0.375;

if (b > 0.75) b = 0.75;

else if (b < 0.5) b = 0.5;

for (y = 5; y < 25; y+=2)

{

float k = ((x ^ y) & 2) ? b : 1.0-b;

CGContextSetRGBFillColor(context, k, k, k, k);

CGContextFillRect(context, CGRectMake(x, y, 2, 2));

}

}

CGContextSetRGBFillColor(context, 1.0, 1.0, 1.0, 1.0);

CGContextMoveToPoint(context, 4, 15);

CGContextAddArcToPoint(context, 4, 4, 15, 4, 4);

CGContextAddArcToPoint(context, 26, 4, 26, 15, 4);

CGContextAddArcToPoint(context, 26, 26, 15, 26, 4);

CGContextAddArcToPoint(context, 4, 26, 4, 15, 4);

CGContextClosePath(context);

CGContextStrokePath(context);

break;

}

}

theCGImage = CGBitmapContextCreateImage(context);

((UITabBarItem *)[tabBar.items objectAtIndex:b]).image = [UIImage imageWithCGImage:theCGImage];

CGImageRelease(theCGImage);

}

CGContextRelease(context);

CGColorSpaceRelease(colorSpace);

}

- (void)dealloc

{

self.slider = nil;

self.tabBar = nil;

[super dealloc];

}

- (void)sliderAction:(id)sender

{

// Redraw the view with the new settings

[((EAGLView*)self.view) drawView];

}

- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item

{

// Recenter the slider (this application does not accumulate multiple filters)

[self.slider setValue:1.0 animated:YES];

// Redraw the view with the new settings

[((EAGLView*)self.view) drawView];

}

@end