GIFLIB Code

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

gifecho - generate a GIF from ASCII text

*****************************************************************************/
// SPDX-License-Identifier: MIT
// SPDX-File-Copyright-Txt: (C) Copyright 1989 Gershon Elber

#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 "gifecho"

#define MAX_NUM_TEXT_LINES 100 /* Maximum number of lines in file. */

#define LINE_LEN 256 /* Maximum length of one text line. */

#define DEFAULT_FG_INDEX 1 /* Text foreground index. */

#define DEFAULT_COLOR_RED 255 /* Text foreground color. */
#define DEFAULT_COLOR_GREEN 255
#define DEFAULT_COLOR_BLUE 255

static char *VerStr = PROGRAM_NAME VERSION_COOKIE __DATE__ ", " __TIME__ "\n";
static char *CtrlStr = PROGRAM_NAME
    " v%- s%-ClrMapSize!d f%-FGClr!d c%-R|G|B!d!d!d t%-\"Text\"!s h%-";

static unsigned int RedColor = DEFAULT_COLOR_RED,
                    GreenColor = DEFAULT_COLOR_GREEN,
                    BlueColor = DEFAULT_COLOR_BLUE;

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, ImageWidth, ImageHeight, NumOfLines, LogNumLevels,
	    ErrorCode, NumLevels, ColorMapSize = 1,
	                          ForeGroundIndex = DEFAULT_FG_INDEX;
	bool Error, ClrMapSizeFlag = false, ForeGroundFlag = false,
	            TextLineFlag = false, HelpFlag = false, ColorFlag = false,
	            GifNoisyPrint = false;
	char *TextLines[MAX_NUM_TEXT_LINES];
	GifRowType RasterBuffer[GIF_FONT_HEIGHT];
	ColorMapObject *ColorMap;
	GifFileType *GifFile;

	if ((Error =
	         GAGetArgs(argc, argv, CtrlStr, &GifNoisyPrint, &ClrMapSizeFlag,
	                   &ColorMapSize, &ForeGroundFlag, &ForeGroundIndex,
	                   &ColorFlag, &RedColor, &GreenColor, &BlueColor,
	                   &TextLineFlag, &TextLines[0], &HelpFlag)) != false) {
		GAPrintErrMsg(Error);
		GAPrintHowTo(CtrlStr);
		exit(EXIT_FAILURE);
	}

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

	if (ForeGroundIndex > 255 || ForeGroundIndex < 1) {
		GIF_EXIT(
		    "Foregound (-f) should be in the range 1..255, aborted.");
	}

	if (ColorMapSize > 8 || ColorMapSize < 1) {
		GIF_EXIT(
		    "ColorMapSize (-s) should be in the range 1..8, aborted.");
	}

	if (TextLineFlag) {
		NumOfLines = 1;
		ImageHeight = GIF_FONT_HEIGHT;
		ImageWidth = GIF_FONT_WIDTH * strlen(TextLines[0]);
	} else {
		char Line[LINE_LEN];
		NumOfLines = l = 0;
		while (fgets(Line, LINE_LEN - 1, stdin)) {
			for (i = strlen(Line); i > 0 && Line[i - 1] <= ' ';
			     i--) {
				;
			}
			Line[i] = 0;
			if (l < i) {
				l = i;
			}
			TextLines[NumOfLines++] = strdup(Line);
			if (NumOfLines == MAX_NUM_TEXT_LINES) {
				GIF_EXIT(
				    "Input file has too many lines, aborted.");
			}
		}
		if (NumOfLines == 0) {
			GIF_EXIT("No input text, aborted.");
		}
		ImageHeight = GIF_FONT_HEIGHT * NumOfLines;
		ImageWidth = GIF_FONT_WIDTH * l;
	}

	/* Allocate the raster buffer for GIF_FONT_HEIGHT scan lines (one text
	 * line). */
	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);
	}

	/* Dump out screen description with given size and generated color map:
	 */
	for (LogNumLevels = 1, NumLevels = 2; NumLevels < ForeGroundIndex;
	     LogNumLevels++, NumLevels <<= 1) {
		;
	}
	if (NumLevels < (1 << ColorMapSize)) {
		NumLevels = (1 << ColorMapSize);
		LogNumLevels = ColorMapSize;
	}

	if ((ColorMap = GifMakeMapObject(NumLevels, NULL)) == NULL) {
		GIF_EXIT("Failed to allocate memory required, aborted.");
	}

	for (i = 0; i < NumLevels; i++) {
		ColorMap->Colors[i].Red = ColorMap->Colors[i].Green =
		    ColorMap->Colors[i].Blue = 0;
	}
	ColorMap->Colors[ForeGroundIndex].Red = RedColor;
	ColorMap->Colors[ForeGroundIndex].Green = GreenColor;
	ColorMap->Colors[ForeGroundIndex].Blue = BlueColor;

	if (EGifPutScreenDesc(GifFile, ImageWidth, ImageHeight, LogNumLevels, 0,
	                      ColorMap) == GIF_ERROR) {
		QuitGifError(GifFile);
	}

	/* Dump out the image descriptor: */
	if (EGifPutImageDesc(GifFile, 0, 0, ImageWidth, ImageHeight, 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 < NumOfLines; i++) {
		GenRasterTextLine(RasterBuffer, TextLines[i], ImageWidth,
		                  ForeGroundIndex);
		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;
}

/******************************************************************************
 Generate raster bits corresponding to given text
******************************************************************************/
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] = 0;
		}
	}

	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);
}

/* end */