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- /**
- * copy.c
- *
- * Computer Science 50
- * Problem Set 4
- *
- * Copies a BMP piece by piece, just because.
- */
- #include <stdio.h>
- #include <stdlib.h>
- #include "bmp.h"
- int main(int argc, char * argv[]) {
- // ensure proper usage
- if (argc != 4) {
- printf("Usage: ./copy infile outfile\n");
- return 1;
- }
- if (atoi(argv[1]) > 100) {
- printf("Please enter number smaller than 100...");
- return 1;
- }
- // remember filenames
- int n = atoi(argv[1]);
- char * infile = argv[2];
- char * outfile = argv[3];
- // open input file
- FILE * inptr = fopen(infile, "r");
- if (inptr == NULL) {
- printf("Could not open %s.\n", infile);
- return 2;
- }
- // open output file
- FILE * outptr = fopen(outfile, "w");
- if (outptr == NULL) {
- fclose(inptr);
- fprintf(stderr, "Could not create %s.\n", outfile);
- return 3;
- }
- // read infile's BITMAPFILEHEADER
- BITMAPFILEHEADER bf;
- fread( &bf, sizeof(BITMAPFILEHEADER), 1, inptr);
- // read infile's BITMAPINFOHEADER
- BITMAPINFOHEADER bi;
- fread( &bi, sizeof(BITMAPINFOHEADER), 1, inptr);
- // ensure infile is (likely) a 24-bit uncompressed BMP 4.0
- // I added this here because you need to add the sanity check on bf and bi before you actually use them //
- if (bf.bfType != 0x4d42 || bf.bfOffBits != 54 || bi.biSize != 40 ||
- bi.biBitCount != 24 || bi.biCompression != 0) {
- fclose(outptr);
- fclose(inptr);
- fprintf(stderr, "Unsupported file format.\n");
- return 4;
- }
- // copy these file headers so they can be written to output file
- BITMAPFILEHEADER bfo = bf;
- BITMAPINFOHEADER bio = bi;
- // new height and width
- bio.biHeight = bi.biHeight * n;
- bio.biWidth = bi.biWidth * n;
- // determine padding for scanlines
- // old padding
- int padding = (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;
- // new padding
- int newpadding = (4 - bio.biWidth * sizeof(RGBTRIPLE) % 4) % 4;
- bio.biSizeImage = ((bio.biWidth) * sizeof(RGBTRIPLE) + (newpadding)) * abs(bio.biHeight);
- bfo.bfSize = (bio.biSizeImage) + 54;
- // write outfile's BITMAPFILEHEADER
- fwrite( &bfo, sizeof(BITMAPFILEHEADER), 1, outptr);
- // write outfile's BITMAPINFOHEADER
- fwrite( &bio, sizeof(BITMAPINFOHEADER), 1, outptr);
- // value of one scanline
- /*scanLine = (RGBTRIPLE*) malloc(sizeof(RGBTRIPLE) * bio.biWidth);*/
- // iterate over infile's scanlines
- // for each row
- for (int i = 0, biHeight = abs(bi.biHeight); i < biHeight; i++) {
- // for each pixel in row (resize horizontally)
- // iterate over pixels in scanline
- // this loop throw each pixel in one scanline
- for (int j = 0; j < bi.biWidth; j++) {
- // temporary storage
- RGBTRIPLE triple;
- // read RGB triple from infile
- fread( &triple, sizeof(RGBTRIPLE), 1, inptr);
- // write to outile n times
- for (int a = 0; a < n; a++) {
- fwrite(&triple, sizeof(RGBTRIPLE), 1, outptr);
- }
- //skip original padding
- fseek(inptr, padding, SEEK_SET);
- // then add it back as new padding (to demonstrate how)
- for (int k = 0; k < newpadding; k++) {
- fputc(0x00, outptr);
- }
- }
- }
- // close infile
- fclose(inptr);
- // close outfile
- fclose(outptr);
- // that's all folks
- return 0;
- }
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