2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
13 % Read Microsoft Direct Draw Surface Image Format %
20 % Copyright 1999-2011 ImageMagick Studio LLC, a non-profit organization %
21 % dedicated to making software imaging solutions freely available. %
23 % You may not use this file except in compliance with the License. You may %
24 % obtain a copy of the License at %
26 % http://www.imagemagick.org/script/license.php %
28 % Unless required by applicable law or agreed to in writing, software %
29 % distributed under the License is distributed on an "AS IS" BASIS, %
30 % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
31 % See the License for the specific language governing permissions and %
32 % limitations under the License. %
34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
42 #include "MagickCore/studio.h"
43 #include "MagickCore/blob.h"
44 #include "MagickCore/blob-private.h"
45 #include "MagickCore/cache.h"
46 #include "MagickCore/colorspace.h"
47 #include "MagickCore/exception.h"
48 #include "MagickCore/exception-private.h"
49 #include "MagickCore/image.h"
50 #include "MagickCore/image-private.h"
51 #include "MagickCore/list.h"
52 #include "MagickCore/log.h"
53 #include "MagickCore/magick.h"
54 #include "MagickCore/memory_.h"
55 #include "MagickCore/monitor.h"
56 #include "MagickCore/monitor-private.h"
57 #include "MagickCore/profile.h"
58 #include "MagickCore/quantum-private.h"
59 #include "MagickCore/static.h"
60 #include "MagickCore/string_.h"
61 #include "MagickCore/module.h"
62 #include "MagickCore/transform.h"
63 #include "MagickCore/studio.h"
64 #include "MagickCore/blob.h"
65 #include "MagickCore/blob-private.h"
66 #include "MagickCore/colorspace.h"
67 #include "MagickCore/exception.h"
68 #include "MagickCore/exception-private.h"
69 #include "MagickCore/compress.h"
70 #include "MagickCore/image.h"
71 #include "MagickCore/image-private.h"
72 #include "MagickCore/list.h"
73 #include "MagickCore/magick.h"
74 #include "MagickCore/memory_.h"
75 #include "MagickCore/monitor.h"
76 #include "MagickCore/monitor-private.h"
77 #include "MagickCore/pixel-accessor.h"
78 #include "MagickCore/quantum.h"
79 #include "MagickCore/static.h"
80 #include "MagickCore/string_.h"
85 #define DDSD_CAPS 0x00000001
86 #define DDSD_HEIGHT 0x00000002
87 #define DDSD_WIDTH 0x00000004
88 #define DDSD_PITCH 0x00000008
89 #define DDSD_PIXELFORMAT 0x00001000
90 #define DDSD_MIPMAPCOUNT 0x00020000
91 #define DDSD_LINEARSIZE 0x00080000
92 #define DDSD_DEPTH 0x00800000
94 #define DDPF_ALPHAPIXELS 0x00000001
95 #define DDPF_FOURCC 0x00000004
96 #define DDPF_RGB 0x00000040
98 #define FOURCC_DXT1 0x31545844
99 #define FOURCC_DXT3 0x33545844
100 #define FOURCC_DXT5 0x35545844
102 #define DDSCAPS_COMPLEX 0x00000008
103 #define DDSCAPS_TEXTURE 0x00001000
104 #define DDSCAPS_MIPMAP 0x00400000
106 #define DDSCAPS2_CUBEMAP 0x00000200
107 #define DDSCAPS2_CUBEMAP_POSITIVEX 0x00000400
108 #define DDSCAPS2_CUBEMAP_NEGATIVEX 0x00000800
109 #define DDSCAPS2_CUBEMAP_POSITIVEY 0x00001000
110 #define DDSCAPS2_CUBEMAP_NEGATIVEY 0x00002000
111 #define DDSCAPS2_CUBEMAP_POSITIVEZ 0x00004000
112 #define DDSCAPS2_CUBEMAP_NEGATIVEZ 0x00008000
113 #define DDSCAPS2_VOLUME 0x00200000
116 Structure declarations.
118 typedef struct _DDSPixelFormat
130 typedef struct _DDSInfo
146 typedef struct _DDSColors
155 typedef MagickBooleanType
156 DDSDecoder(Image *,DDSInfo *,ExceptionInfo *);
161 #define C565_r(x) (((x) & 0xF800) >> 11)
162 #define C565_g(x) (((x) & 0x07E0) >> 5)
163 #define C565_b(x) ((x) & 0x001F)
165 #define C565_red(x) ( (C565_r(x) << 3 | C565_r(x) >> 2))
166 #define C565_green(x) ( (C565_g(x) << 2 | C565_g(x) >> 4))
167 #define C565_blue(x) ( (C565_b(x) << 3 | C565_b(x) >> 2))
169 #define DIV2(x) ((x) > 1 ? ((x) >> 1) : 1)
174 static MagickBooleanType
175 ReadDDSInfo(Image *image, DDSInfo *dds_info);
178 CalculateColors(unsigned short c0, unsigned short c1,
179 DDSColors *c, MagickBooleanType ignoreAlpha);
181 static MagickBooleanType
182 ReadDXT1(Image *, DDSInfo *,ExceptionInfo *);
184 static MagickBooleanType
185 ReadDXT3(Image *image, DDSInfo *dds_info,ExceptionInfo *);
187 static MagickBooleanType
188 ReadDXT5(Image *image, DDSInfo *dds_info,ExceptionInfo *);
190 static MagickBooleanType
191 ReadUncompressedRGB(Image *image, DDSInfo *dds_info,ExceptionInfo *);
193 static MagickBooleanType
194 ReadUncompressedRGBA(Image *image, DDSInfo *dds_info,ExceptionInfo *);
197 SkipDXTMipmaps(Image *image, DDSInfo *dds_info, int texel_size);
200 SkipRGBMipmaps(Image *image, DDSInfo *dds_info, int pixel_size);
203 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
207 % R e a d D D S I m a g e %
211 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
213 % ReadDDSImage() reads a DirectDraw Surface image file and returns it. It
214 % allocates the memory necessary for the new Image structure and returns a
215 % pointer to the new image.
217 % The format of the ReadDDSImage method is:
219 % Image *ReadDDSImage(const ImageInfo *image_info,ExceptionInfo *exception)
221 % A description of each parameter follows:
223 % o image_info: The image info.
225 % o exception: return any errors or warnings in this structure.
229 static inline size_t Min(size_t one, size_t two)
236 static Image *ReadDDSImage(const ImageInfo *image_info,ExceptionInfo *exception)
243 cubemap = MagickFalse,
244 volume = MagickFalse,
262 assert(image_info != (const ImageInfo *) NULL);
263 assert(image_info->signature == MagickSignature);
264 if (image_info->debug != MagickFalse)
265 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
266 image_info->filename);
267 assert(exception != (ExceptionInfo *) NULL);
268 assert(exception->signature == MagickSignature);
269 image=AcquireImage(image_info,exception);
270 status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
271 if (status == MagickFalse)
273 image=DestroyImageList(image);
274 return((Image *) NULL);
278 Initialize image structure.
280 if (ReadDDSInfo(image, &dds_info) != MagickTrue) {
281 ThrowReaderException(CorruptImageError,"ImproperImageHeader");
284 if (dds_info.ddscaps2 & DDSCAPS2_CUBEMAP)
285 cubemap = MagickTrue;
287 if (dds_info.ddscaps2 & DDSCAPS2_VOLUME && dds_info.depth > 0)
290 (void) SeekBlob(image, 128, SEEK_SET);
293 Determine pixel format
295 if (dds_info.pixelformat.flags & DDPF_RGB)
297 compression = NoCompression;
298 if (dds_info.pixelformat.flags & DDPF_ALPHAPIXELS)
301 decoder = ReadUncompressedRGBA;
306 decoder = ReadUncompressedRGB;
309 else if (dds_info.pixelformat.flags & DDPF_FOURCC)
311 switch (dds_info.pixelformat.fourcc)
316 compression = DXT1Compression;
324 compression = DXT3Compression;
332 compression = DXT5Compression;
340 ThrowReaderException(CorruptImageError, "ImageTypeNotSupported");
346 /* Neither compressed nor uncompressed... thus unsupported */
347 ThrowReaderException(CorruptImageError, "ImageTypeNotSupported");
354 Determine number of faces defined in the cubemap
357 if (dds_info.ddscaps2 & DDSCAPS2_CUBEMAP_POSITIVEX) num_images++;
358 if (dds_info.ddscaps2 & DDSCAPS2_CUBEMAP_NEGATIVEX) num_images++;
359 if (dds_info.ddscaps2 & DDSCAPS2_CUBEMAP_POSITIVEY) num_images++;
360 if (dds_info.ddscaps2 & DDSCAPS2_CUBEMAP_NEGATIVEY) num_images++;
361 if (dds_info.ddscaps2 & DDSCAPS2_CUBEMAP_POSITIVEZ) num_images++;
362 if (dds_info.ddscaps2 & DDSCAPS2_CUBEMAP_NEGATIVEZ) num_images++;
366 num_images = dds_info.depth;
368 for (n = 0; n < num_images; n++)
372 /* Start a new image */
373 AcquireNextImage(image_info,image,exception);
374 if (GetNextImageInList(image) == (Image *) NULL)
376 image = DestroyImageList(image);
377 return((Image *) NULL);
379 image=SyncNextImageInList(image);
382 image->matte = matte;
383 image->compression = compression;
384 image->columns = dds_info.width;
385 image->rows = dds_info.height;
386 image->storage_class = DirectClass;
387 image->endian = LSBEndian;
389 if (image_info->ping != MagickFalse)
391 (void) CloseBlob(image);
392 return(GetFirstImageInList(image));
395 if ((decoder)(image, &dds_info, exception) != MagickTrue)
397 (void) CloseBlob(image);
398 return(GetFirstImageInList(image));
402 if (EOFBlob(image) != MagickFalse)
403 ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
406 (void) CloseBlob(image);
407 return(GetFirstImageInList(image));
410 static MagickBooleanType ReadDDSInfo(Image *image, DDSInfo *dds_info)
416 /* Seek to start of header */
417 (void) SeekBlob(image, 4, SEEK_SET);
419 /* Check header field */
420 hdr_size = ReadBlobLSBLong(image);
424 /* Fill in DDS info struct */
425 dds_info->flags = ReadBlobLSBLong(image);
427 /* Check required flags */
428 required=(size_t) (DDSD_WIDTH | DDSD_HEIGHT | DDSD_PIXELFORMAT);
429 if ((dds_info->flags & required) != required)
432 dds_info->height = ReadBlobLSBLong(image);
433 dds_info->width = ReadBlobLSBLong(image);
434 dds_info->pitchOrLinearSize = ReadBlobLSBLong(image);
435 dds_info->depth = ReadBlobLSBLong(image);
436 dds_info->mipmapcount = ReadBlobLSBLong(image);
438 (void) SeekBlob(image, 44, SEEK_CUR); /* reserved region of 11 DWORDs */
440 /* Read pixel format structure */
441 hdr_size = ReadBlobLSBLong(image);
445 dds_info->pixelformat.flags = ReadBlobLSBLong(image);
446 dds_info->pixelformat.fourcc = ReadBlobLSBLong(image);
447 dds_info->pixelformat.rgb_bitcount = ReadBlobLSBLong(image);
448 dds_info->pixelformat.r_bitmask = ReadBlobLSBLong(image);
449 dds_info->pixelformat.g_bitmask = ReadBlobLSBLong(image);
450 dds_info->pixelformat.b_bitmask = ReadBlobLSBLong(image);
451 dds_info->pixelformat.alpha_bitmask = ReadBlobLSBLong(image);
453 dds_info->ddscaps1 = ReadBlobLSBLong(image);
454 dds_info->ddscaps2 = ReadBlobLSBLong(image);
455 (void) SeekBlob(image, 12, SEEK_CUR); /* 3 reserved DWORDs */
460 static void CalculateColors(unsigned short c0, unsigned short c1,
461 DDSColors *c, MagickBooleanType ignoreAlpha)
463 c->a[0] = c->a[1] = c->a[2] = c->a[3] = 0;
465 c->r[0] = (unsigned char) C565_red(c0);
466 c->g[0] = (unsigned char) C565_green(c0);
467 c->b[0] = (unsigned char) C565_blue(c0);
469 c->r[1] = (unsigned char) C565_red(c1);
470 c->g[1] = (unsigned char) C565_green(c1);
471 c->b[1] = (unsigned char) C565_blue(c1);
473 if (ignoreAlpha == MagickTrue || c0 > c1)
475 c->r[2] = (unsigned char) ((2 * c->r[0] + c->r[1]) / 3);
476 c->g[2] = (unsigned char) ((2 * c->g[0] + c->g[1]) / 3);
477 c->b[2] = (unsigned char) ((2 * c->b[0] + c->b[1]) / 3);
479 c->r[3] = (unsigned char) ((c->r[0] + 2 * c->r[1]) / 3);
480 c->g[3] = (unsigned char) ((c->g[0] + 2 * c->g[1]) / 3);
481 c->b[3] = (unsigned char) ((c->b[0] + 2 * c->b[1]) / 3);
485 c->r[2] = (unsigned char) ((c->r[0] + c->r[1]) / 2);
486 c->g[2] = (unsigned char) ((c->g[0] + c->g[1]) / 2);
487 c->b[2] = (unsigned char) ((c->b[0] + c->b[1]) / 2);
489 c->r[3] = c->g[3] = c->b[3] = 0;
494 static MagickBooleanType ReadDXT1(Image *image, DDSInfo *dds_info,
495 ExceptionInfo *exception)
521 for (y = 0; y < (ssize_t) dds_info->height; y += 4)
523 for (x = 0; x < (ssize_t) dds_info->width; x += 4)
525 /* Get 4x4 patch of pixels to write on */
526 q = QueueAuthenticPixels(image, x, y, Min(4, dds_info->width - x),
527 Min(4, dds_info->height - y),exception);
529 if (q == (Quantum *) NULL)
532 /* Read 8 bytes of data from the image */
533 c0 = ReadBlobLSBShort(image);
534 c1 = ReadBlobLSBShort(image);
535 bits = ReadBlobLSBLong(image);
537 CalculateColors(c0, c1, &colors, MagickFalse);
539 /* Write the pixels */
540 for (j = 0; j < 4; j++)
542 for (i = 0; i < 4; i++)
544 if ((x + i) < (ssize_t) dds_info->width &&
545 (y + j) < (ssize_t) dds_info->height)
547 code = (unsigned char) ((bits >> ((j*4+i)*2)) & 0x3);
548 SetPixelRed(image,ScaleCharToQuantum(colors.r[code]),q);
549 SetPixelGreen(image,ScaleCharToQuantum(colors.g[code]),q);
550 SetPixelBlue(image,ScaleCharToQuantum(colors.b[code]),q);
551 SetPixelAlpha(image,ScaleCharToQuantum(colors.a[code]),q);
552 if (colors.a[code] && (image->matte == MagickFalse))
553 image->matte=MagickTrue; /* Correct matte */
554 q+=GetPixelChannels(image);
559 if (SyncAuthenticPixels(image,exception) == MagickFalse)
564 SkipDXTMipmaps(image, dds_info, 8);
569 static MagickBooleanType ReadDXT3(Image *image, DDSInfo *dds_info,
570 ExceptionInfo *exception)
599 for (y = 0; y < (ssize_t) dds_info->height; y += 4)
601 for (x = 0; x < (ssize_t) dds_info->width; x += 4)
603 /* Get 4x4 patch of pixels to write on */
604 q = QueueAuthenticPixels(image, x, y, Min(4, dds_info->width - x),
605 Min(4, dds_info->height - y),exception);
607 if (q == (Quantum *) NULL)
610 /* Read alpha values (8 bytes) */
611 a0 = ReadBlobLSBLong(image);
612 a1 = ReadBlobLSBLong(image);
614 /* Read 8 bytes of data from the image */
615 c0 = ReadBlobLSBShort(image);
616 c1 = ReadBlobLSBShort(image);
617 bits = ReadBlobLSBLong(image);
619 CalculateColors(c0, c1, &colors, MagickTrue);
621 /* Write the pixels */
622 for (j = 0; j < 4; j++)
624 for (i = 0; i < 4; i++)
626 if ((x + i) < (ssize_t) dds_info->width && (y + j) < (ssize_t) dds_info->height)
628 code = (bits >> ((4*j+i)*2)) & 0x3;
629 SetPixelRed(image,ScaleCharToQuantum(colors.r[code]),q);
630 SetPixelGreen(image,ScaleCharToQuantum(colors.g[code]),q);
631 SetPixelBlue(image,ScaleCharToQuantum(colors.b[code]),q);
633 Extract alpha value: multiply 0..15 by 17 to get range 0..255
636 alpha = 17U * (unsigned char) ((a0 >> (4*(4*j+i))) & 0xf);
638 alpha = 17U * (unsigned char) ((a1 >> (4*(4*(j-2)+i))) & 0xf);
639 SetPixelAlpha(image,ScaleCharToQuantum((unsigned char) alpha),q);
640 q+=GetPixelChannels(image);
645 if (SyncAuthenticPixels(image,exception) == MagickFalse)
650 SkipDXTMipmaps(image, dds_info, 16);
655 static MagickBooleanType ReadDXT5(Image *image, DDSInfo *dds_info,
656 ExceptionInfo *exception)
689 for (y = 0; y < (ssize_t) dds_info->height; y += 4)
691 for (x = 0; x < (ssize_t) dds_info->width; x += 4)
693 /* Get 4x4 patch of pixels to write on */
694 q = QueueAuthenticPixels(image, x, y, Min(4, dds_info->width - x),
695 Min(4, dds_info->height - y),exception);
697 if (q == (Quantum *) NULL)
700 /* Read alpha values (8 bytes) */
701 a0 = (unsigned char) ReadBlobByte(image);
702 a1 = (unsigned char) ReadBlobByte(image);
704 alpha_bits = (MagickSizeType)ReadBlobLSBLong(image)
705 | ((MagickSizeType)ReadBlobLSBShort(image) << 32);
707 /* Read 8 bytes of data from the image */
708 c0 = ReadBlobLSBShort(image);
709 c1 = ReadBlobLSBShort(image);
710 bits = ReadBlobLSBLong(image);
712 CalculateColors(c0, c1, &colors, MagickTrue);
714 /* Write the pixels */
715 for (j = 0; j < 4; j++)
717 for (i = 0; i < 4; i++)
719 if ((x + i) < (ssize_t) dds_info->width &&
720 (y + j) < (ssize_t) dds_info->height)
722 code = (bits >> ((4*j+i)*2)) & 0x3;
723 SetPixelRed(image,ScaleCharToQuantum(colors.r[code]),q);
724 SetPixelGreen(image,ScaleCharToQuantum(colors.g[code]),q);
725 SetPixelBlue(image,ScaleCharToQuantum(colors.b[code]),q);
726 /* Extract alpha value */
727 alpha_code = (size_t) (alpha_bits >> (3*(4*j+i))) & 0x7;
730 else if (alpha_code == 1)
733 alpha = ((8-alpha_code) * a0 + (alpha_code-1) * a1) / 7;
734 else if (alpha_code == 6)
736 else if (alpha_code == 7)
739 alpha = (((6-alpha_code) * a0 + (alpha_code-1) * a1) / 5);
740 SetPixelAlpha(image,ScaleCharToQuantum((unsigned char) alpha),q);
741 q+=GetPixelChannels(image);
746 if (SyncAuthenticPixels(image,exception) == MagickFalse)
751 SkipDXTMipmaps(image, dds_info, 16);
756 static MagickBooleanType ReadUncompressedRGB(Image *image, DDSInfo *dds_info,
757 ExceptionInfo *exception)
765 for (y = 0; y < (ssize_t) dds_info->height; y++)
767 q = QueueAuthenticPixels(image, 0, y, dds_info->width, 1,exception);
769 if (q == (Quantum *) NULL)
772 for (x = 0; x < (ssize_t) dds_info->width; x++)
774 SetPixelBlue(image,ScaleCharToQuantum((unsigned char)
775 ReadBlobByte(image)),q);
776 SetPixelGreen(image,ScaleCharToQuantum((unsigned char)
777 ReadBlobByte(image)),q);
778 SetPixelRed(image,ScaleCharToQuantum((unsigned char)
779 ReadBlobByte(image)),q);
780 if (dds_info->pixelformat.rgb_bitcount == 32)
781 (void) ReadBlobByte(image);
782 q+=GetPixelChannels(image);
785 if (SyncAuthenticPixels(image,exception) == MagickFalse)
789 SkipRGBMipmaps(image, dds_info, 3);
794 static MagickBooleanType ReadUncompressedRGBA(Image *image, DDSInfo *dds_info,
795 ExceptionInfo *exception)
803 for (y = 0; y < (ssize_t) dds_info->height; y++)
805 q = QueueAuthenticPixels(image, 0, y, dds_info->width, 1,exception);
807 if (q == (Quantum *) NULL)
810 for (x = 0; x < (ssize_t) dds_info->width; x++)
812 SetPixelBlue(image,ScaleCharToQuantum((unsigned char)
813 ReadBlobByte(image)),q);
814 SetPixelGreen(image,ScaleCharToQuantum((unsigned char)
815 ReadBlobByte(image)),q);
816 SetPixelRed(image,ScaleCharToQuantum((unsigned char)
817 ReadBlobByte(image)),q);
818 SetPixelAlpha(image,ScaleCharToQuantum((unsigned char)
819 ReadBlobByte(image)),q);
820 q+=GetPixelChannels(image);
823 if (SyncAuthenticPixels(image,exception) == MagickFalse)
827 SkipRGBMipmaps(image, dds_info, 4);
833 Skip the mipmap images for compressed (DXTn) dds files
835 static void SkipDXTMipmaps(Image *image, DDSInfo *dds_info, int texel_size)
848 Only skip mipmaps for textures and cube maps
850 if (dds_info->ddscaps1 & DDSCAPS_MIPMAP
851 && (dds_info->ddscaps1 & DDSCAPS_TEXTURE
852 || dds_info->ddscaps2 & DDSCAPS2_CUBEMAP))
854 w = DIV2(dds_info->width);
855 h = DIV2(dds_info->height);
858 Mipmapcount includes the main image, so start from one
860 for (i = 1; (i < (ssize_t) dds_info->mipmapcount) && w && h; i++)
862 offset = (MagickOffsetType) ((w + 3) / 4) * ((h + 3) / 4) * texel_size;
863 (void) SeekBlob(image, offset, SEEK_CUR);
872 Skip the mipmap images for uncompressed (RGB or RGBA) dds files
874 static void SkipRGBMipmaps(Image *image, DDSInfo *dds_info, int pixel_size)
887 Only skip mipmaps for textures and cube maps
889 if (dds_info->ddscaps1 & DDSCAPS_MIPMAP
890 && (dds_info->ddscaps1 & DDSCAPS_TEXTURE
891 || dds_info->ddscaps2 & DDSCAPS2_CUBEMAP))
893 w = DIV2(dds_info->width);
894 h = DIV2(dds_info->height);
897 Mipmapcount includes the main image, so start from one
899 for (i=1; (i < (ssize_t) dds_info->mipmapcount) && w && h; i++)
901 offset = (MagickOffsetType) w * h * pixel_size;
902 (void) SeekBlob(image, offset, SEEK_CUR);
911 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
919 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
921 % IsDDS() returns MagickTrue if the image format type, identified by the
922 % magick string, is DDS.
924 % The format of the IsDDS method is:
926 % MagickBooleanType IsDDS(const unsigned char *magick,const size_t length)
928 % A description of each parameter follows:
930 % o magick: compare image format pattern against these bytes.
932 % o length: Specifies the length of the magick string.
935 static MagickBooleanType IsDDS(const unsigned char *magick,const size_t length)
939 if (LocaleNCompare((char *) magick,"DDS ", 4) == 0)
945 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
949 % R e g i s t e r D D S I m a g e %
953 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
955 % RegisterDDSImage() adds attributes for the DDS image format to
956 % the list of supported formats. The attributes include the image format
957 % tag, a method to read and/or write the format, whether the format
958 % supports the saving of more than one frame to the same file or blob,
959 % whether the format supports native in-memory I/O, and a brief
960 % description of the format.
962 % The format of the RegisterDDSImage method is:
964 % RegisterDDSImage(void)
967 ModuleExport size_t RegisterDDSImage(void)
972 entry = SetMagickInfo("DDS");
973 entry->decoder = (DecodeImageHandler *) ReadDDSImage;
974 entry->magick = (IsImageFormatHandler *) IsDDS;
975 entry->seekable_stream=MagickTrue;
976 entry->description = ConstantString("Microsoft DirectDraw Surface");
977 entry->module = ConstantString("DDS");
978 (void) RegisterMagickInfo(entry);
979 return(MagickImageCoderSignature);
984 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
988 % U n r e g i s t e r D D S I m a g e %
992 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
994 % UnregisterDDSImage() removes format registrations made by the
995 % DDS module from the list of supported formats.
997 % The format of the UnregisterDDSImage method is:
999 % UnregisterDDSImage(void)
1002 ModuleExport void UnregisterDDSImage(void)
1004 (void) UnregisterMagickInfo("DDS");