libansilove

xbin.c (4952B)

---

 /*
  * xbin.c
  * libansilove 1.2.4
  * https://www.ansilove.org
  *
  * Copyright (c) 2011-2020 Stefan Vogt, Brian Cassidy, and Frederic Cambus
  * All rights reserved.
  *
  * libansilove is licensed under the BSD 2-Clause License.
  * See LICENSE file for details.
  */
 
 #include <gd.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include "ansilove.h"
 #include "config.h"
 #include "drawchar.h"
 #include "fonts.h"
 #include "output.h"
 
 #define XBIN_HEADER_LENGTH 11 /* 4 + 1 + 2 + 2 + 1 + 1 */
 #define XBIN_PALETTE_LENGTH 48
 
 int
 ansilove_xbin(struct ansilove_ctx *ctx, struct ansilove_options *options)
 {
 	if (ctx == NULL || options == NULL) {
 		if (ctx)
 			ctx->error = ANSILOVE_INVALID_PARAM;
 
 		return -1;
 	}
 
 	if (ctx->length < XBIN_HEADER_LENGTH) {
 		ctx->error = ANSILOVE_FORMAT_ERROR;
 		return -1;
 	}
 
 	const uint8_t *font_data;
 	uint8_t *font_data_xbin = NULL;
 
 	if (strncmp((char *)ctx->buffer, "XBIN\x1a", 5) != 0) {
 		ctx->error = ANSILOVE_FORMAT_ERROR;
 		return -1;
 	}
 
 	uint32_t xbin_width = (ctx->buffer[6] << 8) + ctx->buffer[5];
 	uint32_t xbin_height = (ctx->buffer[8] << 8) + ctx->buffer[7];
 	uint32_t xbin_fontsize = ctx->buffer[9];
 	uint32_t xbin_flags = ctx->buffer[10];
 
 	if (xbin_fontsize == 0) {
 		xbin_fontsize = 16;
 	}
 
 	if (xbin_fontsize > 32) {
 		ctx->error = ANSILOVE_FORMAT_ERROR;
 		return -1;
 	}
 
 	gdImagePtr canvas;
 
 	canvas = gdImageCreate(8 * xbin_width, xbin_fontsize * xbin_height);
 
 	if (!canvas) {
 		ctx->error = ANSILOVE_GD_ERROR;
 		return -1;
 	}
 
 	uint32_t colors[16];
 	uint32_t offset = XBIN_HEADER_LENGTH;
 
 	/* palette */
 	if ((xbin_flags & 1) == 1) {
 		size_t index, loop;
 
 		if (offset + XBIN_PALETTE_LENGTH > ctx->length) {
 			ctx->error = ANSILOVE_FORMAT_ERROR;
 			return -1;
 		}
 
 		for (loop = 0; loop < 16; loop++) {
 			index = (loop * 3) + offset;
 
 			colors[loop] = gdImageColorAllocate(canvas,
 			    (ctx->buffer[index] << 2 | ctx->buffer[index] >> 4),
 			    (ctx->buffer[index + 1] << 2 | ctx->buffer[index + 1] >> 4),
 			    (ctx->buffer[index + 2] << 2 | ctx->buffer[index + 2] >> 4));
 		}
 
 		offset += XBIN_PALETTE_LENGTH;
 	} else {
 		for (size_t i = 0; i < 16; i++) {
 			colors[i] = gdImageColorAllocate(canvas,
 			    vga_palette_red[i], vga_palette_green[i],
 			    vga_palette_blue[i]);
 		}
 	}
 
 	/* font */
 	if ((xbin_flags & 2) == 2) {
 		uint32_t numchars = (xbin_flags & 0x10 ? 512 : 256);
 		size_t fontsz = xbin_fontsize * numchars;
 
 		if (offset + fontsz > ctx->length) {
 			ctx->error = ANSILOVE_FORMAT_ERROR;
 			return -1;
 		}
 
 		/* allocate memory to contain the XBin font */
 		font_data_xbin = (uint8_t *)malloc(fontsz);
 		if (font_data_xbin == NULL) {
 			ctx->error = ANSILOVE_MEMORY_ERROR;
 			return -1;
 		}
 
 		memcpy(font_data_xbin, ctx->buffer+offset, fontsz);
 
 		font_data = font_data_xbin;
 
 		offset += fontsz;
 	} else {
 		/* using default 80x25 font */
 		font_data = font_pc_80x25;
 		xbin_fontsize = 16;
 	}
 
 	uint32_t column = 0, row = 0, foreground, background;
 	int32_t character, attribute;
 
 	/* read compressed xbin */
 	if ((xbin_flags & 4) == 4) {
 		while (offset < ctx->length && row != xbin_height) {
 			uint32_t ctype = ctx->buffer[offset] & 0xC0;
 			uint32_t counter = (ctx->buffer[offset] & 0x3F) + 1;
 
 			character = -1;
 			attribute = -1;
 
 			offset++;
 			while (counter--) {
 				/* none */
 				if (ctype == 0) {
 					character = ctx->buffer[offset];
 					attribute = ctx->buffer[offset + 1];
 					offset += 2;
 				}
 				/* char */
 				else if (ctype == 0x40) {
 					if (character == -1) {
 						character = ctx->buffer[offset];
 						offset++;
 					}
 					attribute = ctx->buffer[offset];
 					offset++;
 				}
 				/* attr */
 				else if (ctype == 0x80) {
 					if (attribute == -1) {
 						attribute = ctx->buffer[offset];
 						offset++;
 					}
 					character = ctx->buffer[offset];
 					offset++;
 				}
 				/* both */
 				else {
 					if (character == -1) {
 						character = ctx->buffer[offset];
 						offset++;
 					}
 					if (attribute == -1) {
 						attribute = ctx->buffer[offset];
 						offset++;
 					}
 				}
 
 				background = (attribute & 240) >> 4;
 				foreground = attribute & 15;
 
 				drawchar(canvas, font_data, 8, xbin_fontsize,
 				    column, row, colors[background],
 				    colors[foreground], character);
 
 				column++;
 
 				if (column == xbin_width) {
 					column = 0;
 					row++;
 				}
 			}
 		}
 	} else {
 		/* read uncompressed xbin */
 		while (offset < ctx->length && row != xbin_height) {
 			if (column == xbin_width) {
 				column = 0;
 				row++;
 			}
 
 			character = ctx->buffer[offset];
 			attribute = ctx->buffer[offset+1];
 
 			background = (attribute & 240) >> 4;
 			foreground = attribute & 15;
 
 			drawchar(canvas, font_data, 8, xbin_fontsize,
 			    column, row, colors[background],
 			    colors[foreground], character);
 
 			column++;
 			offset += 2;
 		}
 	}
 
 	/* create output file */
 	if (output(ctx, options, canvas) != 0) {
 		free(font_data_xbin);
 		font_data = NULL;
 		return -1;
 	}
 
 	free(font_data_xbin);
 
 	return 0;
 }