/* * Copyright (c) 2011 Martin Decky * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * - The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /** @addtogroup imgmap * @{ */ /** * @file */ #include #include #include #include #include #include "imgmap.h" typedef struct { uint8_t id_length; uint8_t cmap_type; uint8_t img_type; uint16_t cmap_first_entry; uint16_t cmap_entries; uint8_t cmap_bpp; uint16_t startx; uint16_t starty; uint16_t width; uint16_t height; uint8_t img_bpp; uint8_t img_descr; } __attribute__((packed)) tga_header_t; typedef enum { CMAP_NOT_PRESENT = 0, CMAP_PRESENT = 1, CMAP_RESERVED_START = 2, CMAP_PRIVATE_START = 128 } cmap_type_t; typedef enum { IMG_EMTPY = 0, IMG_CMAP = 1, IMG_BGRA = 2, IMG_GRAY = 3, IMG_CMAP_RLE = 9, IMG_BGRA_RLE = 10, IMG_GRAY_RLE = 11 } img_type_t; typedef struct { cmap_type_t cmap_type; img_type_t img_type; uint16_t cmap_first_entry; uint16_t cmap_entries; uint8_t cmap_bpp; uint16_t startx; uint16_t starty; uint16_t width; uint16_t height; uint8_t img_bpp; uint8_t img_alpha_bpp; uint8_t img_alpha_dir; void *id_data; size_t id_length; void *cmap_data; size_t cmap_length; void *img_data; size_t img_length; } tga_t; /** Decode Truevision TGA header * * @param[in] data Memory representation of TGA. * @param[in] size Size of the representation (in bytes). * @param[out] tga Decoded TGA. * * @return True on succesful decoding. * @return False on failure. * */ static bool decode_tga_header(void *data, size_t size, tga_t *tga) { /* Header sanity check */ if (size < sizeof(tga_header_t)) return false; tga_header_t *head = (tga_header_t *) data; /* Image ID field */ tga->id_data = data + sizeof(tga_header_t); tga->id_length = head->id_length; if (size < sizeof(tga_header_t) + tga->id_length) return false; /* Color map type */ tga->cmap_type = head->cmap_type; /* Image type */ tga->img_type = head->img_type; /* Color map specification */ tga->cmap_first_entry = uint16_t_le2host(head->cmap_first_entry); tga->cmap_entries = uint16_t_le2host(head->cmap_entries); tga->cmap_bpp = head->cmap_bpp; tga->cmap_data = tga->id_data + tga->id_length; tga->cmap_length = ALIGN_UP(tga->cmap_entries * tga->cmap_bpp, 8) >> 3; if (size < sizeof(tga_header_t) + tga->id_length + tga->cmap_length) return false; /* Image specification */ tga->startx = uint16_t_le2host(head->startx); tga->starty = uint16_t_le2host(head->starty); tga->width = uint16_t_le2host(head->width); tga->height = uint16_t_le2host(head->height); tga->img_bpp = head->img_bpp; tga->img_alpha_bpp = head->img_descr & 0x0f; tga->img_alpha_dir = (head->img_descr & 0xf0) >> 4; tga->img_data = tga->cmap_data + tga->cmap_length; tga->img_length = ALIGN_UP(tga->width * tga->height * tga->img_bpp, 8) >> 3; if (size < sizeof(tga_header_t) + tga->id_length + tga->cmap_length + tga->img_length) return false; return true; } /** Decode Truevision TGA format * * Decode Truevision TGA format and create an image map * from it. The supported variants of TGA are currently * limited to uncompressed 24 bit true-color images without * alpha channel. * * @param[in] data Memory representation of TGA. * @param[in] size Size of the representation (in bytes). * * @return Newly allocated image map. * @return NULL on error or unsupported format. * */ imgmap_t *imgmap_decode_tga(void *data, size_t size) { tga_t tga; if (!decode_tga_header(data, size, &tga)) return NULL; /* * Check for unsupported features. */ switch (tga.cmap_type) { case CMAP_NOT_PRESENT: break; default: /* Unsupported */ return NULL; } switch (tga.img_type) { case IMG_BGRA: if (tga.img_bpp != 24) return NULL; break; case IMG_GRAY: if (tga.img_bpp != 8) return NULL; break; default: /* Unsupported */ return NULL; } if (tga.img_alpha_bpp != 0) return NULL; sysarg_t twidth = tga.startx + tga.width; sysarg_t theight = tga.starty + tga.height; size_t bsize = twidth * theight * 3; imgmap_t *imgmap = (imgmap_t *) malloc(sizeof(imgmap_t) + bsize); if (imgmap == NULL) return NULL; imgmap->size = sizeof(imgmap_t) + bsize; imgmap->width = twidth; imgmap->height = theight; imgmap->visual = VISUAL_BGR_8_8_8; memset(imgmap->data, 0, bsize); /* * TGA is encoded in a bottom-up manner. */ switch (tga.img_type) { case IMG_BGRA: for (sysarg_t y = tga.starty; y < theight; y++) { size_t src_offset = (y - tga.starty) * tga.width * 3; size_t dst_offset = ((theight - y - 1) * twidth + tga.startx) * 3; memcpy(imgmap->data + dst_offset, tga.img_data + src_offset, tga.width * 3); } break; case IMG_GRAY: for (sysarg_t y = tga.starty; y < theight; y++) { for (sysarg_t x = tga.startx; x < twidth; x++) { uint8_t val = ((uint8_t *) tga.img_data)[(y - tga.starty) * tga.width + (x - tga.startx)]; size_t dst_offset = ((theight - y - 1) * twidth + x) * 3; memset(imgmap->data + dst_offset, val, 3); } } break; default: break; } return imgmap; } /** @} */