Fern Screensaver : Part 4
Comments (0) I’ve now completed the Fern Screensaver in Objective-C for the Mac! Surprisingly, using Objective-C was not that far from C/C++. In fact, much of my code could be pasted directly in. That includes the variables, math functions, etc. Also, Mac has done a good job of documenting it’s libraries so using the NSObjects was not that difficult between Google and a quick reference search along with the example screensaver code. I’m going to hit a few key differences and then post the entire file I edited. XCode does the templating pretty well.
First, all the variables are at the top of the code so they don’t change as the program advances frames.
// VARIABLES
float mat[4][7] = {
//...
@implementation ZackScreenSaverView
Secondly, I had to use implement my NSObjects at the start of the -(void)animateOneFrame method. The size = [self bounds].size; calls the screensize. It’ll take some time to get used to the method calls in Objective-C!
- (void)animateOneFrame
{
NSRect dot;
NSSize size;
NSColor *color;
NSBezierPath *path;
float red,green,blue,alpha;
size = [self bounds].size;
The framework has some good methods for getting random floats, or any integer type!
// random number p = SSRandomFloatBetween(0.0,1.0);
Finally, it took some new methods to draw my dots to the screen.
// set dot dot = NSMakeRect(jx,jy,1.0,1.0); // make dot path = [NSBezierPath bezierPathWithRect:dot]; // draw dot [path stroke];
Other than that, the rest is pretty much the same. I encourage those more used to Objective-C and programming for Mac products to comment about the use of this code and correct any bad assumptions! Here is the code in it’s entirety (note that I’ve taken out the redraw at this time)…
//
// ZackScreenSaverView.m
// ZackScreenSaver
//
// Created by Zachary D. Skelton on 5/30/10.
// Copyright (c) 2010, Skelton Networks. All rights reserved.
//
#import "ZackScreenSaverView.h"
// VARIABLES
float mat[4][7] = {
{0.0,0.0,0.0,0.16,0.0,0.0,0.01},
{0.85,0.04,-0.04,0.85,0.0,1.6,0.85},
{0.2,-0.25,0.23,0.22,0.0,1.6,0.07},
{-0.15,0.28,0.26,0.24,0.0,0.44,0.07}
};
// constant sets
float xa = -5.5;
float xb = 6.5;
float ya = -0.5;
float yb = 10.5;
// x and y to be altered
float x = 0.0;
float y = 0.0;
// screen/image size
int ix = 512;
int iy = 512;
// floats for math fulction
float p = 0.0;
float x0 = 0;
float jx = 0;
float jy = 0;
// variables to control function
int i = 0;
int k = 1;
int end = 10000;
@implementation ZackScreenSaverView
- (id)initWithFrame:(NSRect)frame isPreview:(BOOL)isPreview
{
self = [super initWithFrame:frame isPreview:isPreview];
if (self) {
[self setAnimationTimeInterval:1/30.0];
}
return self;
}
- (void)startAnimation
{
[super startAnimation];
}
- (void)stopAnimation
{
[super stopAnimation];
}
- (void)drawRect:(NSRect)rect
{
[super drawRect:rect];
}
- (void)animateOneFrame
{
NSRect dot;
NSSize size;
NSColor *color;
NSBezierPath *path;
float red,green,blue,alpha;
size = [self bounds].size;
ix = size.width;
iy = size.height;
dot = NSMakeRect(ix/2,iy/2,1.0,1.0);
red = 255.0;
green = 255.0;
blue = 255.0;
alpha = 255.0;
color = [NSColor colorWithCalibratedRed: red
green: green
blue: blue
alpha: alpha];
[color set];
// random number
p = SSRandomFloatBetween(0.0,1.0);
// find random i
if(p <= mat[0][6])
i = 0;
else if(p <= (mat[0][6] + mat[1][6]))
i = 1;
else if(p <= (mat[0][6] + mat[1][6] + mat[2][6]))
i = 2;
else
i = 3;
// super math function
x0 = ((x*mat[i][0])+(y*mat[i][1])+mat[i][4]);
y = (x*mat[i][2]+y*mat[i][3]+mat[i][5]);
x = x0;
jx = ((x-xa)/(xb-xa)*(ix-1));
jy = (iy-1)-(y-ya)/(yb-ya)*iy-1;
// set dot
dot = NSMakeRect(jx,jy,1.0,1.0);
// make dot
path = [NSBezierPath bezierPathWithRect:dot];
// draw dot
[path stroke];
// CLEANUP
/*
if(k == end) {
k = 0;
//sleep(5);
} else
k += 1;
*/
return;
}
- (BOOL)hasConfigureSheet
{
return NO;
}
- (NSWindow*)configureSheet
{
return nil;
}
@end
RSS