GIFLIB Code

/*****************************************************************************

gifcolor - generate color test-pattern GIFs

SPDX-License-Identifier: MIT

*****************************************************************************/

#include <ctype.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "getarg.h"
#include "gif_lib.h"

#define PROGRAM_NAME "gifcolor"

#define LINE_LEN 40
#define IMAGEWIDTH LINE_LEN *GIF_FONT_WIDTH

static char *VersionStr = PROGRAM_NAME VERSION_COOKIE
    "	Gershon Elber,	" __DATE__ ",   " __TIME__ "\n"
    "(C) Copyright 1989 Gershon Elber.\n";
static char *CtrlStr = PROGRAM_NAME " v%- b%-Background!d h%-";

static int BackGround = 0;
static void QuitGifError(GifFileType *GifFile);
static void GenRasterTextLine(GifRowType *RasterBuffer, char *TextLine,
                              int BufferWidth, int ForeGroundIndex);

/******************************************************************************
 Interpret the command line and generate the given GIF file.
******************************************************************************/
int main(int argc, char **argv) {
	int i, j, l, GifNoisyPrint, ColorMapSize, ErrorCode;
	bool Error, BackGroundFlag = false, HelpFlag = false;
	char Line[LINE_LEN];
	GifRowType RasterBuffer[GIF_FONT_HEIGHT];
	ColorMapObject *ColorMap;
	GifFileType *GifFile;
	GifColorType ScratchMap[256];
	int red, green, blue;

	if ((Error = GAGetArgs(argc, argv, CtrlStr, &GifNoisyPrint,
	                       &BackGroundFlag, &BackGround, &HelpFlag)) !=
	    false) {
		GAPrintErrMsg(Error);
		GAPrintHowTo(CtrlStr);
		exit(EXIT_FAILURE);
	}

	if (HelpFlag) {
		(void)fprintf(stderr, VersionStr, GIFLIB_MAJOR, GIFLIB_MINOR);
		GAPrintHowTo(CtrlStr);
		exit(EXIT_SUCCESS);
	}

	/* Allocate the raster buffer for GIF_FONT_HEIGHT scan lines. */
	for (i = 0; i < GIF_FONT_HEIGHT; i++) {
		if ((RasterBuffer[i] = (GifRowType)malloc(
		         sizeof(GifPixelType) * IMAGEWIDTH)) == NULL) {
			GIF_EXIT(
			    "Failed to allocate memory required, aborted.");
		}
	}

	/* Open stdout for the output file: */
	if ((GifFile = EGifOpenFileHandle(1, &ErrorCode)) == NULL) {
		PrintGifError(ErrorCode);
		exit(EXIT_FAILURE);
	}

	/* Read the color map in ColorFile into this color map: */
	ColorMapSize = 0;
	while (fscanf(stdin, "%*3d %3d %3d %3d\n", &red, &green, &blue) == 3) {
		if (ColorMapSize < 256) {
			ScratchMap[ColorMapSize].Red = red;
			ScratchMap[ColorMapSize].Green = green;
			ScratchMap[ColorMapSize].Blue = blue;
			ColorMapSize++;
		} else {
			GIF_EXIT("Too many color map triples, aborting.");
		}
	}

	if ((ColorMap = GifMakeMapObject(1 << GifBitSize(ColorMapSize),
	                                 ScratchMap)) == NULL) {
		GIF_EXIT("Failed to allocate memory required, aborted.");
	}

	if (EGifPutScreenDesc(
	        GifFile, IMAGEWIDTH, ColorMapSize * GIF_FONT_HEIGHT,
	        GifBitSize(ColorMapSize), BackGround, ColorMap) == GIF_ERROR) {
		QuitGifError(GifFile);
	}

	/* Dump out the image descriptor: */
	if (EGifPutImageDesc(GifFile, 0, 0, IMAGEWIDTH,
	                     ColorMapSize * GIF_FONT_HEIGHT, false,
	                     NULL) == GIF_ERROR) {
		QuitGifError(GifFile);
	}

	GifQprintf("\n%s: Image 1 at (%d, %d) [%dx%d]:     ", PROGRAM_NAME,
	           GifFile->Image.Left, GifFile->Image.Top,
	           GifFile->Image.Width, GifFile->Image.Height);

	for (i = l = 0; i < ColorMap->ColorCount; i++) {
		(void)snprintf(
		    Line, sizeof(Line), "Color %-3d: [%-3d, %-3d, %-3d] ", i,
		    ColorMap->Colors[i].Red, ColorMap->Colors[i].Green,
		    ColorMap->Colors[i].Blue);
		GenRasterTextLine(RasterBuffer, Line, IMAGEWIDTH, i);
		for (j = 0; j < GIF_FONT_HEIGHT; j++) {
			if (EGifPutLine(GifFile, RasterBuffer[j], IMAGEWIDTH) ==
			    GIF_ERROR) {
				QuitGifError(GifFile);
			}
			GifQprintf("\b\b\b\b%-4d", l++);
		}
	}

	if (EGifCloseFile(GifFile, &ErrorCode) == GIF_ERROR) {
		PrintGifError(ErrorCode);
		exit(EXIT_FAILURE);
	}

	return 0;
}

/******************************************************************************
 Close output file (if open), and exit.
******************************************************************************/
static void GenRasterTextLine(GifRowType *RasterBuffer, char *TextLine,
                              int BufferWidth, int ForeGroundIndex) {
	unsigned char Byte, Mask;
	int i, j, k, CharPosX, Len = strlen(TextLine);

	for (i = 0; i < BufferWidth; i++)
		for (j = 0; j < GIF_FONT_HEIGHT; j++)
			RasterBuffer[j][i] = BackGround;

	for (i = CharPosX = 0; i < Len; i++, CharPosX += GIF_FONT_WIDTH) {
		unsigned char c = TextLine[i];
		for (j = 0; j < GIF_FONT_HEIGHT; j++) {
			Byte = GifAsciiTable8x8[(unsigned short)c][j];
			for (k = 0, Mask = 128; k < GIF_FONT_WIDTH;
			     k++, Mask >>= 1)
				if (Byte & Mask)
					RasterBuffer[j][CharPosX + k] =
					    ForeGroundIndex;
		}
	}
}

/******************************************************************************
 Close output file (if open), and exit.
******************************************************************************/
static void QuitGifError(GifFileType *GifFile) {
	if (GifFile != NULL) {
		PrintGifError(GifFile->Error);
		EGifCloseFile(GifFile, NULL);
	}
	exit(EXIT_FAILURE);
}