Coloring of a rectangle

Question

Hi Everyone,

I'm a newbie to Graphics.I'm drawing a rectangle which will change its color after one second.

- (void)drawRect:(CGRect)rect {
    [self setWidthHeightOfRectangle];
    [self changeColorOfNumbers];
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGContextClearRect(ctx, rect);

    // Draw a solid square

    CGContextSetRGBFillColor(ctx, 255, 255, 255, 1);
    CGContextFillRect(ctx, CGRectMake(0.0, 24.0, 380.0, 2.0));
    CGContextSetRGBFillColor(ctx, redNumber, greenNumber, blueNumber, 1);
    CGContextFillRect(ctx, frameToDraw);
}

I'm changing the color of the rectangle using the changeColorOfNumbers method. Here is the method

- (void)changeColorOfNumbers {
iHit++;
if (iHit==100) {
    redNumber=249;
    greenNumber=252;
    blueNumber=0;

} else if (iHit==200) {
    redNumber=0;
    greenNumber=168;
    blueNumber=245;

} else if (iHit==300) {
    redNumber=255;
    greenNumber=0;
    blueNumber=140;

} else if (iHit==400) {
    redNumber=255;
    greenNumber=125;
    blueNumber=0;

} else if (iHit==500) {
    redNumber=0;
    greenNumber=176;
    blueNumber=72;

} else if (iHit==600) {
    redNumber=128;
    greenNumber=0;
    blueNumber=148;

} else if (iHit==700) {
    redNumber=8;
    greenNumber=79;
    blueNumber=168;

} else if (iHit==800) {
    redNumber=127;
    greenNumber=212;
    blueNumber=20;

} else if (iHit==900) {
    redNumber=255;
    greenNumber=0;
    blueNumber=0;

} else if (iHit==1) {
    redNumber=0;
    greenNumber=0;
    blueNumber=0;
    frameToDraw=CGRectMake(0.0, 0.0, 0.0, 50.0);
} else if (iHit==2) {
    redNumber=255;
    greenNumber=255;
    blueNumber=255;
}
}

Problem is that some of the RGB colors that I'm applying aren't showing up. What am I doing wrong here?.....

Thanks...

Answer 1

Color components must vary from 0 to 1 - try normalize them by dividing on 255.0f;

Answer 2

The RGB library methods expect floats between 0.0 and 1.0. If you want to store your colors internally as integers like that, divide them by 255.0 before passing them to those methods.