So now my square is completely green, but I believe it ressizes correctly.
my code is as follows:
#include <stdio.h>
#include <stdlib.h>
#include "bmp.h"
int main(int argc, char *argv[])
{
//***************************************************************************
// ensure proper usage
if (argc != 4)
{
fprintf(stderr, "Usage: ./resize n infile outfile\n");
return 1;
}
int n = atoi(argv[1]);
char *infile = argv[2];
char *outfile = argv[3];
//if scalefactor 'n' is wrong
if (99 < n)
{
fprintf(stderr, "Usage: n must be less than or equal to 100\n");
return 1;
}
if (n < 0)
{
fprintf(stderr, "Usage: n must be a positive integer\n");
return 1;
}
//if image cannot be opened
FILE* image = fopen(infile, "r");
if (image == NULL)
{
fprintf(stderr, "Could not open %s.\n", infile);
return 1;
}
//if resized image cannot be created
FILE* resizedimage = fopen(outfile, "w");
if (resizedimage == NULL)
{
fprintf(stderr, "Could not open %s.\n", outfile);
return 1;
}
//**************************************************************************
// read infile's BITMAPFILEHEADER
BITMAPFILEHEADER bf;
fread(&bf, sizeof(BITMAPFILEHEADER), 1, image);
// read infile's BITMAPINFOHEADER
BITMAPINFOHEADER bi;
fread(&bi, sizeof(BITMAPINFOHEADER), 1, image);
// read infile's RGB triple
RGBTRIPLE rgbt;
fread(&rgbt, sizeof(RGBTRIPLE), 1, image);
// **********************************************************************
// ensure infile image is (likely) a 24-bit uncompressed BMP 4.0
if (bf.bfType != 0x4d42 || bf.bfOffBits != 54 || bi.biSize != 40 ||
bi.biBitCount != 24 || bi.biCompression != 0)
{
fclose(resizedimage);
fclose(image);
fprintf(stderr, "Unsupported file format.\n");
return 1;
}
//************************************************************************
//UPDATING outfiles HEADER INFO...
//update width
int biWidthoriginal = bi.biWidth;
bi.biWidth = (bi.biWidth * n);
//update height
int biHeightoriginal = bi.biHeight;
bi.biHeight = (bi.biHeight * n);
// determine padding for scanlines
int paddingoriginal = (4 - (biWidthoriginal * sizeof(RGBTRIPLE)) % 4) % 4;
int padding = (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;
//update image size
bi.biSizeImage = ((sizeof(RGBTRIPLE) * bi.biWidth) + padding) * abs(bi.biHeight);
//update file size
bf.bfSize = bi.biSizeImage + sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
//***********************************************
// write outfile's BITMAPFILEHEADER
fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, resizedimage);
// write outfile's BITMAPINFOHEADER
fwrite(&bi, sizeof(BITMAPINFOHEADER), 1, resizedimage);
//************************************************************
//RESIZING
// for each row
for (int i = 0; i < abs(biHeightoriginal); i++)
{
// VERTICALLY ITERATE
for (int z = 0; z < n; z++)
{
// for each pixel in a row
for (int j = 0; j < abs(biWidthoriginal); j++)
{
//write to outfile 'n' number of times - HORIZONTALLY ITERATE
for (int k = 0; k < n; k++)
{
fwrite(&rgbt, sizeof(RGBTRIPLE), 1, resizedimage);
}
}
//write outfile's padding
for (int k = 0; k < padding; k++)
{
fputc(0x00, resizedimage);
}
// skip over infiles padding if any
fseek(image, paddingoriginal, SEEK_CUR);
//return to beginning of scanline
fseek(image, abs(-biWidthoriginal*3 - paddingoriginal), SEEK_CUR);
}
//go to end of scanline before iterating over next row
fseek(image, abs(biWidthoriginal*3 + paddingoriginal), SEEK_CUR);
}
// close infile
fclose(image);
// close outfile
fclose(resizedimage);
// success
return 0;
}
at my wits end! any help would be much appreciated. :)