/*******************************************************************
	       Local pixel buffer and pixel draw functions
********************************************************************
    Author: Stan Sclaroff
      Date: January 17, 1999
  Comments: Provided for CS480 programming assignment 1.
********************************************************************/


#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>

#include "types.h"
#include "funcs.h"

/* local state is stored in static global variables */
static PixelBuffer pixelBuffer;
static Color pixelColor;

/* Set current pixel draw color */
void setColor(Color color)
{
  pixelColor.r = color.r;
  pixelColor.g = color.g;
  pixelColor.b = color.b;
}

/* Get current pixel draw color */
Color getColor(void)
{
  return(pixelColor);
}

/* Compare two pixel colors. If same return 1, otherwise 0 */
int sameColor(Color c1, Color c2)
{
  return(memcmp(&c1,&c2,sizeof(Color)) == 0);
}

/* Allocate and initialize the draw buffer */
void initPixelBuffer(int w, int h)
{
  pixelBuffer.width = w;
  pixelBuffer.height = h;
  pixelBuffer.pixels = malloc(sizeof(Color)*w*h);
  clearPixelBuffer();
}

/* set all pixels in draw buffer to 0 */
void clearPixelBuffer(void)
{  
  memset(pixelBuffer.pixels,0,
	 sizeof(Color)*pixelBuffer.height*pixelBuffer.width);
}

/* set a particular pixel to <r,g,b> color */
void setPixel(int x, int y, Color color)
{
  if(x >= pixelBuffer.width || x < 0)
    return;
  if(y >= pixelBuffer.height || y < 0)
    return;
  memcpy(&pixelBuffer.pixels[y*pixelBuffer.width+x], &color, sizeof(Color));
}

/* get a particular pixel's value */
Color getPixel(int x, int y)
{
  return(pixelBuffer.pixels[y*pixelBuffer.width+x]);
}

int getPixelBufferWidth(void)
{
  return(pixelBuffer.width);
}

int getPixelBufferHeight(void)
{
  return(pixelBuffer.height);
}

Color *getPixelBufferAddress(void)
{
  return(&pixelBuffer.pixels[0]);
}