Thread: Need help making a program in C

hey all, I've made this function that makes a thing like this:


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So far, I have all the code done, I just can't get the function to generate this in a ppm file to work. The program compiles and everything, it just gives weird ppm files as a result. Here's my code:

Code:

#include <stdio.h>

void make_header (int width, int height);
void print_Row (int yValue, int width, int height);
void make_pixel (unsigned char r, unsigned char g, unsigned char b);

void make_header (int width, int height)
{
    fprintf(stdout,"P6\n");
    fprintf(stdout,"%d %d 255\n",width, height);
}
void print_Row (int yValue, int width, int height){
	int x;
	float slope1 = height / width, slope2 = -1*slope1;

	for(yValue = 0; yValue < height; yValue++){
		for(x = 0; x < width; x++){
			if(yValue < slope1 * x && yValue < slope2 * x){
				make_pixel(255, 0, 0);}//Makes red
			else if(yValue<slope1 * x && yValue >= slope2 * x){
				make_pixel(0, 255, 0);}//Makes green
			else if(yValue>= slope1 * x && yValue>=slope2 * x){
				make_pixel(0, 0, 255);}//Makes blue
			else(yValue >= slope1 * x && yValue < slope2 * x);{
				make_pixel(255, 255, 0);}//Makes yellow
			}
		}
	}
void make_pixel (unsigned char r, unsigned char g, unsigned char b)
{
	fprintf(stdout,"%c%c%c", r,g,b);
}
int main()
{
    	float slope1, slope2, wmid, hmid, yValue ;
   	int width, height;
    
    	fprintf(stderr, "\nEnter a value for width: ");
    	fscanf(stdin, "%d", &width);
    	fprintf(stderr, "\nEnter a value for height: ");
    	fscanf(stdin, "%d", &height);
    	make_header (width, height);
	slope1 = height / width;
    	slope2 = -1*slope1;
    	
	print_Row (yValue, width, height);
return(0);
}

Basically what I need it to do is to divide a rectangle of dimensions entered by the user into 4 quadrants (divided diagonally from the corners). I'm trying to do this by dividing the rectangle by two slope functions and then trying to see if a certain point is above both, above one but below another, or below both and it determines which color to print.

I can't seem to get it to do this, can somebody help me please?

Well how about fixing the fact you're passing garbage to your function.

Code:

$ gcc -Wall bar.c
bar.c: In function ‘print_Row’:
bar.c:24:11: warning: statement with no effect [-Wunused-value]
bar.c: In function ‘main’:
bar.c:35:35: warning: unused variable ‘hmid’ [-Wunused-variable]
bar.c:35:29: warning: unused variable ‘wmid’ [-Wunused-variable]
bar.c:35:21: warning: variable ‘slope2’ set but not used [-Wunused-but-set-variable]
bar.c:46:13: warning: ‘yValue’ is used uninitialized in this function [-Wuninitialized]