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/* Copyright (C) 2017 Wildfire Games.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/*
* TGA codec.
*/
#include "precompiled.h"
#include "lib/byte_order.h"
#include "tex_codec.h"
#include "lib/bits.h"
#pragma pack(push, 1)
enum TgaImgType
{
TGA_TRUE_COLOR = 2, // uncompressed 24 or 32 bit direct RGB
TGA_GREY = 3 // uncompressed 8 bit direct greyscale
};
enum TgaImgDesc
{
TGA_RIGHT_TO_LEFT = BIT(4),
TGA_TOP_DOWN = BIT(5),
};
typedef struct
{
u8 img_id_len; // 0 - no image identifier present
u8 color_map_type; // 0 - no color map present
u8 img_type; // see TgaImgType
u8 color_map[5]; // unused
u16 x_origin; // unused
u16 y_origin; // unused
u16 w;
u16 h;
u8 bpp; // bits per pixel
u8 img_desc;
}
TgaHeader;
// TGA file: header [img id] [color map] image data
#pragma pack(pop)
Status TexCodecTga::transform(Tex* UNUSED(t), size_t UNUSED(transforms)) const
{
return INFO::TEX_CODEC_CANNOT_HANDLE;
}
bool TexCodecTga::is_hdr(const u8* file) const
{
TgaHeader* hdr = (TgaHeader*)file;
// the first TGA header doesn't have a magic field;
// we can only check if the first 4 bytes are valid
// .. not direct color
if(hdr->color_map_type != 0)
return false;
// .. wrong color type (not uncompressed greyscale or RGB)
if(hdr->img_type != TGA_TRUE_COLOR && hdr->img_type != TGA_GREY)
return false;
// note: we can't check img_id_len or color_map[0] - they are
// undefined and may assume any value.
return true;
}
bool TexCodecTga::is_ext(const OsPath& extension) const
{
return extension == L".tga";
}
size_t TexCodecTga::hdr_size(const u8* file) const
{
size_t hdr_size = sizeof(TgaHeader);
if(file)
{
TgaHeader* hdr = (TgaHeader*)file;
hdr_size += hdr->img_id_len;
}
return hdr_size;
}
// requirements: uncompressed, direct color, bottom up
Status TexCodecTga::decode(u8* RESTRICT data, size_t UNUSED(size), Tex* RESTRICT t) const
{
const TgaHeader* hdr = (const TgaHeader*)data;
const u8 type = hdr->img_type;
const size_t w = read_le16(&hdr->w);
const size_t h = read_le16(&hdr->h);
const size_t bpp = hdr->bpp;
const u8 desc = hdr->img_desc;
size_t flags = 0;
flags |= (desc & TGA_TOP_DOWN)? TEX_TOP_DOWN : TEX_BOTTOM_UP;
if(desc & 0x0F) // alpha bits
flags |= TEX_ALPHA;
if(bpp == 8)
flags |= TEX_GREY;
if(type == TGA_TRUE_COLOR)
flags |= TEX_BGR;
// sanity checks
// .. storing right-to-left is just stupid;
// we're not going to bother converting it.
if(desc & TGA_RIGHT_TO_LEFT)
WARN_RETURN(ERR::TEX_INVALID_LAYOUT);
t->m_Width = w;
t->m_Height = h;
t->m_Bpp = bpp;
t->m_Flags = flags;
return INFO::OK;
}
Status TexCodecTga::encode(Tex* RESTRICT t, DynArray* RESTRICT da) const
{
u8 img_desc = 0;
if(t->m_Flags & TEX_TOP_DOWN)
img_desc |= TGA_TOP_DOWN;
if(t->m_Bpp == 32)
img_desc |= 8; // size of alpha channel
TgaImgType img_type = (t->m_Flags & TEX_GREY)? TGA_GREY : TGA_TRUE_COLOR;
size_t transforms = t->m_Flags;
transforms &= ~TEX_ORIENTATION; // no flip needed - we can set top-down bit.
transforms ^= TEX_BGR; // TGA is native BGR.
const TgaHeader hdr =
{
0, // no image identifier present
0, // no color map present
(u8)img_type,
{0,0,0,0,0}, // unused (color map)
0, 0, // unused (origin)
(u16)t->m_Width,
(u16)t->m_Height,
(u8)t->m_Bpp,
img_desc
};
const size_t hdr_size = sizeof(hdr);
return tex_codec_write(t, transforms, &hdr, hdr_size, da);
}
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