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Anonymous committed fae607c

Merge in BMP support, sync up LSB functions.

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  • Parent commits e438a34
  • Branches GD-2.0

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+/* $Id$ */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+	gd_bmp.c
+
+	Bitmap format support for libgd
+
+	* Written 2007, Scott MacVicar
+	---------------------------------------------------------------------------
+
+	Todo:
+
+	RLE4, RLE8 and Bitfield encoding
+	Add full support for Windows v4 and Windows v5 header formats
+
+	----------------------------------------------------------------------------
+ */
+
+#ifndef BMP_H
+#define BMP_H	1
+
+#define BMP_PALETTE_3 1
+#define BMP_PALETTE_4 2
+
+#define BMP_WINDOWS_V3 40
+#define BMP_OS2_V1 12
+#define BMP_OS2_V2 64
+#define BMP_WINDOWS_V4 108
+#define BMP_WINDOWS_V5 124
+
+#define BMP_BI_RGB 0
+#define BMP_BI_RLE8 1
+#define BMP_BI_RLE4 2
+#define BMP_BI_BITFIELDS 3
+#define BMP_BI_JPEG 4
+#define BMP_BI_PNG 5
+
+#define BMP_RLE_COMMAND 0
+#define BMP_RLE_ENDOFLINE 0
+#define BMP_RLE_ENDOFBITMAP 1
+#define BMP_RLE_DELTA 2
+
+#define BMP_RLE_TYPE_RAW 0
+#define BMP_RLE_TYPE_RLE 1
+
+/* BMP header. */
+typedef struct
+{
+	/* 16 bit - header identifying the type */
+	signed short int magic;
+
+	/* 32bit - size of the file */
+	int size;
+
+	/* 16bit - these two are in the spec but "reserved" */
+	signed short int reserved1;
+	signed short int reserved2;
+
+	/* 32 bit - offset of the bitmap header from data in bytes */
+	signed int off;
+
+} bmp_hdr_t;
+
+/* BMP info. */
+typedef struct
+{
+	/* 16bit - Type, ie Windows or OS/2 for the palette info */
+	signed short int type;
+	/* 32bit - The length of the bitmap information header in bytes. */
+	signed int len;
+
+	/* 32bit - The width of the bitmap in pixels. */
+	signed int width;
+
+	/* 32bit - The height of the bitmap in pixels. */
+	signed int height;
+
+	/* 8 bit - The bitmap data is specified in top-down order. */
+	signed char topdown;
+
+	/* 16 bit - The number of planes.  This must be set to a value of one. */
+	signed short int numplanes;
+
+	/* 16 bit - The number of bits per pixel. */
+	signed short int depth;
+
+	/* 32bit - The type of compression used. */
+	signed int enctype;
+
+	/* 32bit - The size of the image in bytes. */
+	signed int size;
+
+	/* 32bit - The horizontal resolution in pixels/metre. */
+	signed int hres;
+
+	/* 32bit - The vertical resolution in pixels/metre. */
+	signed int vres;
+
+	/* 32bit - The number of color indices used by the bitmap. */
+	signed int numcolors;
+
+	/* 32bit - The number of color indices important for displaying the bitmap. */
+	signed int mincolors;
+
+} bmp_info_t;
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
 BGD_DECLARE(gdImagePtr) gdImageCreateFromTgaCtx(gdIOCtx* ctx);
 BGD_DECLARE(gdImagePtr) gdImageCreateFromTgaPtr(int size, void *data);
 
+BGD_DECLARE(gdImagePtr) gdImageCreateFromBmp (FILE * inFile);
+BGD_DECLARE(gdImagePtr) gdImageCreateFromBmpPtr (int size, void *data);
+BGD_DECLARE(gdImagePtr) gdImageCreateFromBmpCtx (gdIOCtxPtr infile);
+
 /* A custom data source. */
 /* The source function must return -1 on error, otherwise the number
         of bytes fetched. 0 is EOF, not an error! */
 BGD_DECLARE(void *) gdImageTiffPtr(gdImagePtr im, int *size);
 BGD_DECLARE(void) gdImageTiffCtx(gdImagePtr image, gdIOCtx *out);
 
+BGD_DECLARE(void *) gdImageBmpPtr(gdImagePtr im, int *size, int compression);
+BGD_DECLARE(void) gdImageBmp(gdImagePtr im, FILE *outFile, int compression);
+BGD_DECLARE(void) gdImageBmpCtx(gdImagePtr im, gdIOCtxPtr out, int compression);
+
 /* 2.0.12: Compression level: 0-9 or -1, where 0 is NO COMPRESSION at all,
   1 is FASTEST but produces larger files, 9 provides the best
   compression (smallest files) but takes a long time to compress, and
+/*
+	gd_bmp.c
+
+	Bitmap format support for libgd
+
+	* Written 2007, Scott MacVicar
+	---------------------------------------------------------------------------
+
+	Todo:
+
+	Bitfield encoding
+
+	----------------------------------------------------------------------------
+ */
+/* $Id$ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdio.h>
+#include <math.h>
+#include <string.h>
+#include <stdlib.h>
+#include "gd.h"
+#include "gdhelpers.h"
+#include "bmp.h"
+
+static int compress_row(unsigned char *uncompressed_row, int length);
+static int build_rle_packet(unsigned char *row, int packet_type, int length, unsigned char *data);
+
+static int bmp_read_header(gdIOCtxPtr infile, bmp_hdr_t *hdr);
+static int bmp_read_info(gdIOCtxPtr infile, bmp_info_t *info);
+static int bmp_read_windows_v3_info(gdIOCtxPtr infile, bmp_info_t *info);
+static int bmp_read_os2_v1_info(gdIOCtxPtr infile, bmp_info_t *info);
+static int bmp_read_os2_v2_info(gdIOCtxPtr infile, bmp_info_t *info);
+
+static int bmp_read_direct(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header);
+static int bmp_read_1bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header);
+static int bmp_read_4bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header);
+static int bmp_read_8bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header);
+static int bmp_read_rle(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info);
+
+#define BMP_DEBUG(s)
+
+static int gdBMPPutWord(gdIOCtx *out, int w)
+{
+	/* Byte order is little-endian */
+	gdPutC(w & 0xFF, out);
+	gdPutC((w >> 8) & 0xFF, out);
+	return 0;
+}
+
+static int gdBMPPutInt(gdIOCtx *out, int w)
+{
+	/* Byte order is little-endian */
+	gdPutC(w & 0xFF, out);
+	gdPutC((w >> 8) & 0xFF, out);
+	gdPutC((w >> 16) & 0xFF, out);
+	gdPutC((w >> 24) & 0xFF, out);
+	return 0;
+}
+
+BGD_DECLARE(void *) gdImageBmpPtr(gdImagePtr im, int *size, int compression)
+{
+	void *rv;
+	gdIOCtx *out = gdNewDynamicCtx(2048, NULL);
+	gdImageBmpCtx(im, out, compression);
+	rv = gdDPExtractData(out, size);
+	out->gd_free(out);
+	return rv;
+}
+
+BGD_DECLARE(void) gdImageBmp(gdImagePtr im, FILE *outFile, int compression)
+{
+	gdIOCtx *out = gdNewFileCtx(outFile);
+	gdImageBmpCtx(im, out, compression);
+	out->gd_free(out);
+}
+
+BGD_DECLARE(void) gdImageBmpCtx(gdImagePtr im, gdIOCtxPtr out, int compression)
+{
+	int bitmap_size = 0, info_size, total_size, padding;
+	int i, row, xpos, pixel;
+	int error = 0;
+	unsigned char *uncompressed_row = NULL, *uncompressed_row_start = NULL;
+	FILE *tmpfile_for_compression = NULL;
+	gdIOCtxPtr out_original = NULL;
+
+	/* No compression if its true colour or we don't support seek */
+	if (im->trueColor) {
+		compression = 0;
+	}
+
+	if (compression == 1 && !out->seek) {
+		/* Try to create a temp file where we can seek */
+		if ((tmpfile_for_compression = tmpfile()) == NULL) {
+			compression = 0;
+		} else {
+			out_original = out;
+			if ((out = (gdIOCtxPtr)gdNewFileCtx(tmpfile_for_compression)) == NULL) {
+				out = out_original;
+				out_original = NULL;
+				compression = 0;
+			}
+		}
+	}
+
+	bitmap_size = ((im->sx * (im->trueColor ? 24 : 8)) / 8) * im->sy;
+
+	/* 40 byte Windows v3 header */
+	info_size = BMP_WINDOWS_V3;
+
+	/* data for the palette */
+	if (!im->trueColor) {
+		info_size += im->colorsTotal * 4;
+		if (compression) {
+			bitmap_size = 0;
+		}
+	}
+
+	/* bitmap header + info header + data */
+	total_size = 14 + info_size + bitmap_size;
+
+	/* write bmp header info */
+	gdPutBuf("BM", 2, out);
+	gdBMPPutInt(out, total_size);
+	gdBMPPutWord(out, 0);
+	gdBMPPutWord(out, 0);
+	gdBMPPutInt(out, 14 + info_size);
+
+	/* write Windows v3 headers */
+	gdBMPPutInt(out, BMP_WINDOWS_V3); /* header size */
+	gdBMPPutInt(out, im->sx); /* width */
+	gdBMPPutInt(out, im->sy); /* height */
+	gdBMPPutWord(out, 1); /* colour planes */
+	gdBMPPutWord(out, (im->trueColor ? 24 : 8)); /* bit count */
+	gdBMPPutInt(out, (compression ? BMP_BI_RLE8 : BMP_BI_RGB)); /* compression */
+	gdBMPPutInt(out, bitmap_size); /* image size */
+	gdBMPPutInt(out, 0); /* H resolution */
+	gdBMPPutInt(out, 0); /* V ressolution */
+	gdBMPPutInt(out, im->colorsTotal); /* colours used */
+	gdBMPPutInt(out, 0); /* important colours */
+
+	/* The line must be divisible by 4, else its padded with NULLs */
+	padding = ((int)(im->trueColor ? 3 : 1) * im->sx) % 4;
+	if (padding) {
+		padding = 4 - padding;
+	}
+
+	/* 8-bit colours */
+	if (!im->trueColor) {
+		for(i = 0; i< im->colorsTotal; ++i) {
+			Putchar(gdImageBlue(im, i), out);
+			Putchar(gdImageGreen(im, i), out);
+			Putchar(gdImageRed(im, i), out);
+			Putchar(0, out);
+        }
+
+		if (compression) {
+			/* Can potentially change this to X + ((X / 128) * 3) */
+			uncompressed_row = uncompressed_row_start = (unsigned char *) gdCalloc(gdImageSX(im) * 2, sizeof(char));
+			if (!uncompressed_row) {
+				/* malloc failed */
+				goto cleanup;
+			}
+		}
+
+        for (row = (im->sy - 1); row >= 0; row--) {
+			if (compression) {
+				memset (uncompressed_row, 0, gdImageSX(im));
+			}
+
+			for (xpos = 0; xpos < im->sx; xpos++) {
+				if (compression) {
+					*uncompressed_row++ = (unsigned char)gdImageGetPixel(im, xpos, row);
+				} else {
+					Putchar(gdImageGetPixel(im, xpos, row), out);
+				}
+			}
+
+			if (!compression) {
+				/* Add padding to make sure we have n mod 4 == 0 bytes per row */
+				for (xpos = padding; xpos > 0; --xpos) {
+					Putchar('\0', out);
+				}
+			} else {
+				int compressed_size = 0;
+				uncompressed_row = uncompressed_row_start;
+				if ((compressed_size = compress_row(uncompressed_row, gdImageSX(im))) < 0) {
+					error = 1;
+					break;
+				}
+				bitmap_size += compressed_size;
+
+
+				gdPutBuf(uncompressed_row, compressed_size, out);
+				Putchar(BMP_RLE_COMMAND, out);
+				Putchar(BMP_RLE_ENDOFLINE, out);
+				bitmap_size += 2;
+			}
+		}
+
+		if (compression && uncompressed_row) {
+			gdFree(uncompressed_row);
+			if (error != 0) {
+				goto cleanup;
+			}
+			/* Update filesize based on new values and set compression flag */
+			Putchar(BMP_RLE_COMMAND, out);
+			Putchar(BMP_RLE_ENDOFBITMAP, out);
+			bitmap_size += 2;
+
+			/* Write new total bitmap size */
+			gdSeek(out, 2);
+			gdBMPPutInt(out, total_size + bitmap_size);
+
+			/* Total length of image data */
+			gdSeek(out, 34);
+			gdBMPPutInt(out, bitmap_size);
+		}
+
+	} else {
+        for (row = (im->sy - 1); row >= 0; row--) {
+			for (xpos = 0; xpos < im->sx; xpos++) {
+				pixel = gdImageGetPixel(im, xpos, row);
+
+				Putchar(gdTrueColorGetBlue(pixel), out);
+				Putchar(gdTrueColorGetGreen(pixel), out);
+				Putchar(gdTrueColorGetRed(pixel), out);
+			}
+
+			/* Add padding to make sure we have n mod 4 == 0 bytes per row */
+			for (xpos = padding; xpos > 0; --xpos) {
+				Putchar('\0', out);
+			}
+		}
+	}
+
+
+	/* If we needed a tmpfile for compression copy it over to out_original */
+	if (tmpfile_for_compression) {
+		unsigned char* copy_buffer = NULL;
+		int buffer_size = 0;
+
+		gdSeek(out, 0);
+		copy_buffer = (unsigned char *) gdMalloc(1024 * sizeof(unsigned char));
+		if (copy_buffer == NULL) {
+			goto cleanup;
+		}
+
+		while ((buffer_size = gdGetBuf(copy_buffer, 1024, out)) != EOF) {
+			if (buffer_size == 0) {
+				break;
+			}
+			gdPutBuf(copy_buffer , buffer_size, out_original);
+		}
+		gdFree(copy_buffer);
+
+		/* Replace the temp with the original which now has data */
+		out->gd_free(out);
+		out = out_original;
+		out_original = NULL;
+	}
+
+cleanup:
+	if (tmpfile_for_compression) {
+#ifdef WIN32
+		_rmtmp();
+#else
+		fclose(tmpfile_for_compression);
+#endif
+		tmpfile_for_compression = NULL;
+	}
+
+	if (out_original) {
+		out_original->gd_free(out_original);
+	}
+	return;
+}
+
+static int compress_row(unsigned char *row, int length)
+{
+	int rle_type = 0;
+	int compressed_length = 0;
+	int pixel = 0, compressed_run = 0, rle_compression = 0;
+	unsigned char *uncompressed_row = NULL, *uncompressed_rowp = NULL, *uncompressed_start = NULL;
+
+	uncompressed_row = (unsigned char *) gdMalloc(length);
+	if (!uncompressed_row) {
+		return -1;
+	}
+
+	memcpy(uncompressed_row, row, length);
+	uncompressed_start = uncompressed_rowp = uncompressed_row;
+
+	for (pixel = 0; pixel < length; pixel++)
+	{
+		if (compressed_run == 0) {
+			uncompressed_row = uncompressed_rowp;
+			compressed_run++;
+			uncompressed_rowp++;
+			rle_type = BMP_RLE_TYPE_RAW;
+			continue;
+		}
+
+		if (compressed_run == 1) {
+			/* Compare next byte */
+			if (memcmp(uncompressed_rowp, uncompressed_rowp - 1, 1) == 0) {
+				rle_type = BMP_RLE_TYPE_RLE;
+			}
+		}
+
+		if (rle_type == BMP_RLE_TYPE_RLE) {
+			if (compressed_run >= 128 || memcmp(uncompressed_rowp, uncompressed_rowp - 1, 1) != 0) {
+				/* more than what we can store in a single run or run is over due to non match, force write */
+				rle_compression = build_rle_packet(row, rle_type, compressed_run, uncompressed_row);
+				row += rle_compression;
+				compressed_length += rle_compression;
+				compressed_run = 0;
+				pixel--;
+			} else {
+				compressed_run++;
+				uncompressed_rowp++;
+			}
+		} else {
+			if (compressed_run >= 128 || memcmp(uncompressed_rowp, uncompressed_rowp - 1, 1) == 0) {
+				/* more than what we can store in a single run or run is over due to match, force write */
+				rle_compression = build_rle_packet(row, rle_type, compressed_run, uncompressed_row);
+				row += rle_compression;
+				compressed_length += rle_compression;
+				compressed_run = 0;
+				pixel--;
+			} else {
+				/* add this pixel to the row */
+				compressed_run++;
+				uncompressed_rowp++;
+			}
+
+		}
+	}
+
+	if (compressed_run) {
+		if (rle_type == BMP_RLE_TYPE_RLE) {
+			compressed_length += build_rle_packet(row, rle_type, compressed_run, uncompressed_row);
+		} else {
+			compressed_length += build_rle_packet(row, rle_type, compressed_run, uncompressed_row);
+		}
+	}
+
+	gdFree(uncompressed_start);
+
+	return compressed_length;
+}
+
+static int build_rle_packet(unsigned char *row, int packet_type, int length, unsigned char *data)
+{
+	int compressed_size = 0;
+	if (length < 1 || length > 128) {
+		return 0;
+	}
+
+	/* Bitmap specific cases is that we can't have uncompressed rows of length 1 or 2 */
+	if (packet_type == BMP_RLE_TYPE_RAW && length < 3) {
+		int i = 0;
+		for (i = 0; i < length; i++) {
+			compressed_size += 2;
+			memset(row, 1, 1);
+			row++;
+
+			memcpy(row, data++, 1);
+			row++;
+		}
+	} else if (packet_type == BMP_RLE_TYPE_RLE) {
+		compressed_size = 2;
+		memset(row, length, 1);
+		row++;
+
+		memcpy(row, data, 1);
+		row++;
+	} else {
+		compressed_size = 2 + length;
+		memset(row, BMP_RLE_COMMAND, 1);
+		row++;
+
+		memset(row, length, 1);
+		row++;
+
+		memcpy(row, data, length);
+		row += length;
+
+		/* Must be an even number for an uncompressed run */
+		if (length % 2) {
+			memset(row, 0, 1);
+			row++;
+			compressed_size++;
+		}
+	}
+	return compressed_size;
+}
+
+BGD_DECLARE(gdImagePtr) gdImageCreateFromBmp(FILE * inFile)
+{
+	gdImagePtr im = 0;
+	gdIOCtx *in = gdNewFileCtx(inFile);
+	im = gdImageCreateFromBmpCtx(in);
+	in->gd_free(in);
+	return im;
+}
+
+BGD_DECLARE(gdImagePtr) gdImageCreateFromBmpPtr(int size, void *data)
+{
+	gdImagePtr im;
+	gdIOCtx *in = gdNewDynamicCtxEx(size, data, 0);
+	im = gdImageCreateFromBmpCtx(in);
+	in->gd_free(in);
+	return im;
+}
+
+BGD_DECLARE(gdImagePtr) gdImageCreateFromBmpCtx(gdIOCtxPtr infile)
+{
+	bmp_hdr_t *hdr;
+	bmp_info_t *info;
+	gdImagePtr im = NULL;
+	int error = 0;
+
+	if (!(hdr= (bmp_hdr_t *)gdCalloc(1, sizeof(bmp_hdr_t)))) {
+		return NULL;
+	}
+
+	if (bmp_read_header(infile, hdr)) {
+		gdFree(hdr);
+		return NULL;
+	}
+
+	if (hdr->magic != 0x4d42) {
+		gdFree(hdr);
+		return NULL;
+	}
+
+	if (!(info = (bmp_info_t *)gdCalloc(1, sizeof(bmp_info_t)))) {
+		gdFree(hdr);
+		return NULL;
+	}
+
+	if (bmp_read_info(infile, info)) {
+		gdFree(hdr);
+		gdFree(info);
+		return NULL;
+	}
+
+	BMP_DEBUG(printf("Numcolours: %d\n", info->numcolors));
+	BMP_DEBUG(printf("Width: %d\n", info->width));
+	BMP_DEBUG(printf("Height: %d\n", info->height));
+	BMP_DEBUG(printf("Planes: %d\n", info->numplanes));
+	BMP_DEBUG(printf("Depth: %d\n", info->depth));
+	BMP_DEBUG(printf("Offset: %d\n", hdr->off));
+
+	if (info->depth >= 16) {
+		im = gdImageCreateTrueColor(info->width, info->height);
+	} else {
+		im = gdImageCreate(info->width, info->height);
+	}
+
+	if (!im) {
+		gdFree(hdr);
+		gdFree(info);
+		return NULL;
+	}
+
+	switch (info->depth) {
+		case 1:
+			BMP_DEBUG(printf("1-bit image\n"));
+			error = bmp_read_1bit(im, infile, info, hdr);
+		break;
+		case 4:
+			BMP_DEBUG(printf("4-bit image\n"));
+			error = bmp_read_4bit(im, infile, info, hdr);
+		break;
+		case 8:
+			BMP_DEBUG(printf("8-bit image\n"));
+			error = bmp_read_8bit(im, infile, info, hdr);
+		break;
+		case 16:
+		case 24:
+		case 32:
+			BMP_DEBUG(printf("Direct BMP image\n"));
+			error = bmp_read_direct(im, infile, info, hdr);
+		break;
+		default:
+			BMP_DEBUG(printf("Unknown bit count\n"));
+			error = 1;
+	}
+
+	gdFree(hdr);
+	gdFree(info);
+
+	if (error) {
+		gdImageDestroy(im);
+		return NULL;
+	}
+
+	return im;
+}
+
+static int bmp_read_header(gdIOCtx *infile, bmp_hdr_t *hdr)
+{
+	if(
+	!gdGetWordLSB(&hdr->magic, infile) ||
+	!gdGetIntLSB(&hdr->size, infile) ||
+	!gdGetWordLSB(&hdr->reserved1, infile) ||
+	!gdGetWordLSB(&hdr->reserved2 , infile) ||
+	!gdGetIntLSB(&hdr->off , infile)
+	) {
+		return 1;
+	}
+	return 0;
+}
+
+static int bmp_read_info(gdIOCtx *infile, bmp_info_t *info)
+{
+	/* read BMP length so we can work out the version */
+	if (!gdGetIntLSB(&info->len, infile)) {
+		return 1;
+	}
+
+	switch (info->len) {
+		/* For now treat Windows v4 + v5 as v3 */
+		case BMP_WINDOWS_V3:
+		case BMP_WINDOWS_V4:
+		case BMP_WINDOWS_V5:
+			BMP_DEBUG(printf("Reading Windows Header\n"));
+			if (bmp_read_windows_v3_info(infile, info)) {
+				return 1;
+			}
+		break;
+		case BMP_OS2_V1:
+			if (bmp_read_os2_v1_info(infile, info)) {
+				return 1;
+			}
+		break;
+		case BMP_OS2_V2:
+			if (bmp_read_os2_v2_info(infile, info)) {
+				return 1;
+			}
+		break;
+		default:
+			BMP_DEBUG(printf("Unhandled bitmap\n"));
+			return 1;
+	}
+	return 0;
+}
+
+static int bmp_read_windows_v3_info(gdIOCtxPtr infile, bmp_info_t *info)
+{
+	if (
+		!gdGetIntLSB(&info->width, infile) ||
+		!gdGetIntLSB(&info->height, infile) ||
+		!gdGetWordLSB(&info->numplanes, infile) ||
+		!gdGetWordLSB(&info->depth, infile) ||
+		!gdGetIntLSB(&info->enctype, infile) ||
+		!gdGetIntLSB(&info->size, infile) ||
+		!gdGetIntLSB(&info->hres, infile) ||
+		!gdGetIntLSB(&info->vres, infile) ||
+		!gdGetIntLSB(&info->numcolors, infile) ||
+		!gdGetIntLSB(&info->mincolors, infile)
+	) {
+		return 1;
+	}
+
+	if (info->height < 0) {
+		info->topdown = 1;
+		info->height = -info->height;
+	} else {
+		info->topdown = 0;
+	}
+
+	info->type = BMP_PALETTE_4;
+
+	if (info->width <= 0 || info->height <= 0 || info->numplanes <= 0 ||
+	  info->depth <= 0  || info->numcolors < 0 || info->mincolors < 0) {
+		return 1;
+	}
+
+	return 0;
+}
+
+static int bmp_read_os2_v1_info(gdIOCtxPtr infile, bmp_info_t *info)
+{
+	if (
+		!gdGetWordLSB((signed short int *)&info->width, infile) ||
+		!gdGetWordLSB((signed short int *)&info->height, infile) ||
+		!gdGetWordLSB(&info->numplanes, infile) ||
+		!gdGetWordLSB(&info->depth, infile)
+	) {
+		return 1;
+	}
+
+	/* OS2 v1 doesn't support topdown */
+	info->topdown = 0;
+
+	info->numcolors = 1 << info->depth;
+	info->type = BMP_PALETTE_3;
+
+	if (info->width <= 0 || info->height <= 0 || info->numplanes <= 0 ||
+	  info->depth <= 0 || info->numcolors < 0) {
+		return 1;
+	}
+
+	return 0;
+}
+
+static int bmp_read_os2_v2_info(gdIOCtxPtr infile, bmp_info_t *info)
+{
+	char useless_bytes[24];
+	if (
+		!gdGetIntLSB(&info->width, infile) ||
+		!gdGetIntLSB(&info->height, infile) ||
+		!gdGetWordLSB(&info->numplanes, infile) ||
+		!gdGetWordLSB(&info->depth, infile) ||
+		!gdGetIntLSB(&info->enctype, infile) ||
+		!gdGetIntLSB(&info->size, infile) ||
+		!gdGetIntLSB(&info->hres, infile) ||
+		!gdGetIntLSB(&info->vres, infile) ||
+		!gdGetIntLSB(&info->numcolors, infile) ||
+		!gdGetIntLSB(&info->mincolors, infile)
+	) {
+		return 1;
+	}
+
+	/* Lets seek the next 24 pointless bytes, we don't care too much about it */
+	if (!gdGetBuf(useless_bytes, 24, infile)) {
+		return 1;
+	}
+
+	if (info->height < 0) {
+		info->topdown = 1;
+		info->height = -info->height;
+	} else {
+		info->topdown = 0;
+	}
+
+	info->type = BMP_PALETTE_4;
+
+	if (info->width <= 0 || info->height <= 0 || info->numplanes <= 0 ||
+	 info->depth <= 0  || info->numcolors < 0 || info->mincolors < 0) {
+		return 1;
+	}
+
+
+	return 0;
+}
+
+static int bmp_read_direct(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header)
+{
+	int ypos = 0, xpos = 0, row = 0;
+	int padding = 0, alpha = 0, red = 0, green = 0, blue = 0;
+	signed short int data = 0;
+
+	switch(info->enctype) {
+		case BMP_BI_RGB:
+			/* no-op */
+		break;
+
+		case BMP_BI_BITFIELDS:
+			if (info->depth == 24) {
+				BMP_DEBUG(printf("Bitfield compression isn't supported for 24-bit\n"));
+				return 1;
+			}
+			BMP_DEBUG(printf("Currently no bitfield support\n"));
+			return 1;
+		break;
+
+		case BMP_BI_RLE8:
+			if (info->depth != 8) {
+				BMP_DEBUG(printf("RLE is only valid for 8-bit images\n"));
+				return 1;
+			}
+		case BMP_BI_RLE4:
+			if (info->depth != 4) {
+				BMP_DEBUG(printf("RLE is only valid for 4-bit images\n"));
+				return 1;
+			}
+		case BMP_BI_JPEG:
+		case BMP_BI_PNG:
+		default:
+			BMP_DEBUG(printf("Unsupported BMP compression format\n"));
+			return 1;
+	}
+
+	/* There is a chance the data isn't until later, would be wierd but it is possible */
+	if (gdTell(infile) != header->off) {
+		/* Should make sure we don't seek past the file size */
+		gdSeek(infile, header->off);
+	}
+
+	/* The line must be divisible by 4, else its padded with NULLs */
+	padding = ((int)(info->depth / 8) * info->width) % 4;
+	if (padding) {
+		padding = 4 - padding;
+	}
+
+
+	for (ypos = 0; ypos < info->height; ++ypos) {
+		if (info->topdown) {
+			row = ypos;
+		} else {
+			row = info->height - ypos - 1;
+		}
+
+		for (xpos = 0; xpos < info->width; xpos++) {
+			if (info->depth == 16) {
+				if (!gdGetWordLSB(&data, infile)) {
+					return 1;
+				}
+				BMP_DEBUG(printf("Data: %X\n", data));
+				red = ((data & 0x7C00) >> 10) << 3;
+				green = ((data & 0x3E0) >> 5) << 3;
+				blue = (data & 0x1F) << 3;
+				BMP_DEBUG(printf("R: %d, G: %d, B: %d\n", red, green, blue));
+			} else if (info->depth == 24) {
+				if (!gdGetByte(&blue, infile) || !gdGetByte(&green, infile) || !gdGetByte(&red, infile)) {
+					return 1;
+				}
+			} else {
+				if (!gdGetByte(&blue, infile) || !gdGetByte(&green, infile) || !gdGetByte(&red, infile) || !gdGetByte(&alpha, infile)) {
+					return 1;
+				}
+			}
+			/*alpha = gdAlphaMax - (alpha >> 1);*/
+			gdImageSetPixel(im, xpos, row, gdTrueColor(red, green, blue));
+		}
+		for (xpos = padding; xpos > 0; --xpos) {
+			if (!gdGetByte(&red, infile)) {
+				return 1;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int bmp_read_palette(gdImagePtr im, gdIOCtxPtr infile, int count, int read_four)
+{
+	int i;
+	int r, g, b, z;
+
+	for (i = 0; i < count; i++) {
+		if (
+		!gdGetByte(&r, infile) ||
+		!gdGetByte(&g, infile) ||
+		!gdGetByte(&b, infile) ||
+		(read_four && !gdGetByte(&z, infile))
+		) {
+			return 1;
+		}
+		im->red[i] = r;
+		im->green[i] = g;
+		im->blue[i] = b;
+		im->open[i] = 1;
+	}
+	return 0;
+}
+
+static int bmp_read_1bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header)
+{
+	int ypos = 0, xpos = 0, row = 0, index = 0;
+	int padding = 0, current_byte = 0, bit = 0;
+
+	if (info->enctype != BMP_BI_RGB) {
+		return 1;
+	}
+
+	if (!info->numcolors) {
+		info->numcolors = 2;
+	} else if (info->numcolors < 0 || info->numcolors > 2) {
+		return 1;
+	}
+
+	if (bmp_read_palette(im, infile, info->numcolors, (info->type == BMP_PALETTE_4))) {
+		return 1;
+	}
+
+	im->colorsTotal = info->numcolors;
+
+	/* There is a chance the data isn't until later, would be wierd but it is possible */
+	if (gdTell(infile) != header->off) {
+		/* Should make sure we don't seek past the file size */
+		gdSeek(infile, header->off);
+	}
+
+	/* The line must be divisible by 4, else its padded with NULLs */
+	padding = ((int)ceill(0.1 * info->width)) % 4;
+	if (padding) {
+		padding = 4 - padding;
+	}
+
+	for (ypos = 0; ypos < info->height; ++ypos) {
+		if (info->topdown) {
+			row = ypos;
+		} else {
+			row = info->height - ypos - 1;
+		}
+
+		for (xpos = 0; xpos < info->width; xpos += 8) {
+			/* Bitmaps are always aligned in bytes so we'll never overflow */
+			if (!gdGetByte(&current_byte, infile)) {
+				return 1;
+			}
+
+			for (bit = 0; bit < 8; bit++) {
+				index = ((current_byte & (0x80 >> bit)) != 0 ? 0x01 : 0x00);
+				if (im->open[index]) {
+					im->open[index] = 0;
+				}
+				gdImageSetPixel(im, xpos + bit, row, index);
+				/* No need to read anything extra */
+				if ((xpos + bit) >= info->width) {
+					break;
+				}
+			}
+		}
+
+		for (xpos = padding; xpos > 0; --xpos) {
+			if (!gdGetByte(&index, infile)) {
+				return 1;
+			}
+		}
+	}
+	return 0;
+}
+
+static int bmp_read_4bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header)
+{
+	int ypos = 0, xpos = 0, row = 0, index = 0;
+	int padding = 0, current_byte = 0;
+
+	if (info->enctype != BMP_BI_RGB && info->enctype != BMP_BI_RLE4) {
+		return 1;
+	}
+
+	if (!info->numcolors) {
+		info->numcolors = 16;
+	} else if (info->numcolors < 0 || info->numcolors > 16) {
+		return 1;
+	}
+
+	if (bmp_read_palette(im, infile, info->numcolors, (info->type == BMP_PALETTE_4))) {
+		return 1;
+	}
+
+	im->colorsTotal = info->numcolors;
+
+	/* There is a chance the data isn't until later, would be wierd but it is possible */
+	if (gdTell(infile) != header->off) {
+		/* Should make sure we don't seek past the file size */
+		gdSeek(infile, header->off);
+	}
+
+	/* The line must be divisible by 4, else its padded with NULLs */
+	padding = ((int)ceil(0.5 * info->width)) % 4;
+	if (padding) {
+		padding = 4 - padding;
+	}
+
+	switch (info->enctype) {
+		case BMP_BI_RGB:
+		for (ypos = 0; ypos < info->height; ++ypos) {
+			if (info->topdown) {
+				row = ypos;
+			} else {
+				row = info->height - ypos - 1;
+			}
+
+			for (xpos = 0; xpos < info->width; xpos += 2) {
+				if (!gdGetByte(&current_byte, infile)) {
+					return 1;
+				}
+
+				index = (current_byte >> 4) & 0x0f;
+				if (im->open[index]) {
+					im->open[index] = 0;
+				}
+				gdImageSetPixel(im, xpos, row, index);
+
+				/* This condition may get called often, potential optimsations */
+				if (xpos >= info->width) {
+					break;
+				}
+
+				index = current_byte & 0x0f;
+				if (im->open[index]) {
+					im->open[index] = 0;
+				}
+				gdImageSetPixel(im, xpos + 1, row, index);
+			}
+
+			for (xpos = padding; xpos > 0; --xpos) {
+				if (!gdGetByte(&index, infile)) {
+					return 1;
+				}
+			}
+		}
+		break;
+
+		case BMP_BI_RLE4:
+		if (bmp_read_rle(im, infile, info)) {
+			return 1;
+		}
+		break;
+
+		default:
+			return 1;
+	}
+	return 0;
+}
+
+static int bmp_read_8bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header)
+{
+	int ypos = 0, xpos = 0, row = 0, index = 0;
+	int padding = 0;
+
+	if (info->enctype != BMP_BI_RGB && info->enctype != BMP_BI_RLE8) {
+		return 1;
+	}
+
+	if (!info->numcolors) {
+		info->numcolors = 256;
+	} else if (info->numcolors < 0 || info->numcolors > 256) {
+		return 1;
+	}
+
+	if (bmp_read_palette(im, infile, info->numcolors, (info->type == BMP_PALETTE_4))) {
+		return 1;
+	}
+
+	im->colorsTotal = info->numcolors;
+
+	/* There is a chance the data isn't until later, would be wierd but it is possible */
+	if (gdTell(infile) != header->off) {
+		/* Should make sure we don't seek past the file size */
+		gdSeek(infile, header->off);
+	}
+
+	/* The line must be divisible by 4, else its padded with NULLs */
+	padding = (1 * info->width) % 4;
+	if (padding) {
+		padding = 4 - padding;
+	}
+
+	switch (info->enctype) {
+		case BMP_BI_RGB:
+		for (ypos = 0; ypos < info->height; ++ypos) {
+			if (info->topdown) {
+				row = ypos;
+			} else {
+				row = info->height - ypos - 1;
+			}
+
+			for (xpos = 0; xpos < info->width; ++xpos) {
+				if (!gdGetByte(&index, infile)) {
+					return 1;
+				}
+
+				if (im->open[index]) {
+					im->open[index] = 0;
+				}
+				gdImageSetPixel(im, xpos, row, index);
+			}
+			/* Could create a new variable, but it isn't really worth it */
+			for (xpos = padding; xpos > 0; --xpos) {
+				if (!gdGetByte(&index, infile)) {
+					return 1;
+				}
+			}
+		}
+		break;
+
+		case BMP_BI_RLE8:
+		if (bmp_read_rle(im, infile, info)) {
+			return 1;
+		}
+		break;
+
+		default:
+			return 1;
+	}
+	return 0;
+}
+
+static int bmp_read_rle(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info)
+{
+	int ypos = 0, xpos = 0, row = 0, index = 0;
+	int rle_length = 0, rle_data = 0;
+	int padding = 0;
+	int i = 0, j = 0;
+	int pixels_per_byte = 8 / info->depth;
+
+	for (ypos = 0; ypos < info->height && xpos <= info->width;) {
+		if (!gdGetByte(&rle_length, infile) || !gdGetByte(&rle_data, infile)) {
+			return 1;
+		}
+		row = info->height - ypos - 1;
+
+		if (rle_length != BMP_RLE_COMMAND) {
+			if (im->open[rle_data]) {
+				im->open[rle_data] = 0;
+			}
+
+			for (i = 0; (i < rle_length) && (xpos < info->width);) {
+				for (j = 1; (j <= pixels_per_byte) && (xpos < info->width) && (i < rle_length); j++, xpos++, i++) {
+					index = (rle_data & (((1 << info->depth) - 1) << (8 - (j * info->depth)))) >> (8 - (j * info->depth));
+					if (im->open[index]) {
+						im->open[index] = 0;
+					}
+					gdImageSetPixel(im, xpos, row, index);
+				}
+			}
+		} else if (rle_length == BMP_RLE_COMMAND && rle_data > 2) {
+			/* Uncompressed RLE needs to be even */
+			padding = 0;
+			for (i = 0; (i < rle_data) && (xpos < info->width); i += pixels_per_byte) {
+				int max_pixels = pixels_per_byte;
+
+				if (!gdGetByte(&index, infile)) {
+					return 1;
+				}
+				padding++;
+
+				if (rle_data - i < max_pixels) {
+					max_pixels = rle_data - i;
+				}
+
+				for (j = 1; (j <= max_pixels)  && (xpos < info->width); j++, xpos++) {
+					int temp = (index >> (8 - (j * info->depth))) & ((1 << info->depth) - 1);
+					if (im->open[temp]) {
+						im->open[temp] = 0;
+					}
+					gdImageSetPixel(im, xpos, row, temp);
+				}
+			}
+
+			/* Make sure the bytes read are even */
+			if (padding % 2 && !gdGetByte(&index, infile)) {
+				return 1;
+			}
+		} else if (rle_length == BMP_RLE_COMMAND && rle_data == BMP_RLE_ENDOFLINE) {
+			/* Next Line */
+			xpos = 0;
+			ypos++;
+		} else if (rle_length == BMP_RLE_COMMAND && rle_data == BMP_RLE_DELTA) {
+			/* Delta Record, used for bmp files that contain other data*/
+			if (!gdGetByte(&rle_length, infile) || !gdGetByte(&rle_data, infile)) {
+				return 1;
+			}
+			xpos += rle_length;
+			ypos += rle_data;
+		} else if (rle_length == BMP_RLE_COMMAND && rle_data == BMP_RLE_ENDOFBITMAP) {
+			/* End of bitmap */
+			break;
+		}
+	}
+	return 0;
+}
 
 int gdGetWordLSB(signed short int *result, gdIOCtx *ctx)
 {
-	int high = 0, low = 0;
-
-	low = (ctx->getC)(ctx);
-	if(low == EOF) {
-		return 0;
+	unsigned int high = 0, low = 0;
+	low = (ctx->getC) (ctx);
+	if (low == EOF) {
+ 		return 0;
 	}
 
-	high = (ctx->getC)(ctx);
-	if(high == EOF) {
-		return 0;
+	high = (ctx->getC) (ctx);
+	if (high == EOF) {
+ 		return 0;
 	}
 
-	if(result) {
+	if (result) {
 		*result = (high << 8) | low;
 	}
 
 
 int gdGetIntLSB(signed int *result, gdIOCtx *ctx)
 {
-	int c = 0, r = 0;
+	int c = 0;
+	unsigned int r = 0;
 
-	c = (ctx->getC)(ctx);
-	if(c == EOF) {
-		return 0;
+	c = (ctx->getC) (ctx);
+	if (c == EOF) {
+ 		return 0;
 	}
-
 	r |= (c << 24);
 	r >>= 8;
 
-	c = (ctx->getC)(ctx);
-	if(c == EOF) {
-		return 0;
+	c = (ctx->getC) (ctx);
+	if (c == EOF) {
+ 		return 0;
 	}
-
 	r |= (c << 24);
 	r >>= 8;
 
-	c = (ctx->getC)(ctx);
-	if(c == EOF) {
-		return 0;
+	c = (ctx->getC) (ctx);
+	if (c == EOF) {
+ 		return 0;
 	}
-
 	r |= (c << 24);
 	r >>= 8;
 
-	c = (ctx->getC)(ctx);
-	if(c == EOF) {
-		return 0;
+	c = (ctx->getC) (ctx);
+	if (c == EOF) {
+ 		return 0;
 	}
-
 	r |= (c << 24);
 
-	if(result) {
-		*result = r;
+	if (result) {
+		*result = (signed int)r;
 	}
 
 	return 1;