コード例 #1
0
                    public static int stbi__paeth(int a, int b, int c)
                    {
                        var p  = a + b - c;
                        var pa = CRuntime.abs(p - a);
                        var pb = CRuntime.abs(p - b);
                        var pc = CRuntime.abs(p - c);

                        if ((pa <= pb) && (pa <= pc))
                        {
                            return(a);
                        }
                        if (pb <= pc)
                        {
                            return(b);
                        }
                        return(c);
                    }
コード例 #2
0
                    public static void *stbi__bmp_load(stbi__context s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri)
                    {
                        byte *_out_;
                        var   mr              = (uint)0;
                        var   mg              = (uint)0;
                        var   mb              = (uint)0;
                        var   ma              = (uint)0;
                        uint  all_a           = 0;
                        var   pal             = stackalloc byte[256 * 4];
                        var   psize           = 0;
                        var   i               = 0;
                        var   j               = 0;
                        var   width           = 0;
                        var   flip_vertically = 0;
                        var   pad             = 0;
                        var   target          = 0;
                        var   info            = new stbi__bmp_data();

                        info.all_a = 255;
                        if (stbi__bmp_parse_header(s, &info) == null)
                        {
                            return(null);
                        }
                        flip_vertically = ((int)s.img_y > 0) ? 1 : 0;
                        s.img_y         = (uint)CRuntime.abs((int)s.img_y);
                        mr    = info.mr;
                        mg    = info.mg;
                        mb    = info.mb;
                        ma    = info.ma;
                        all_a = info.all_a;
                        if (info.hsz == 12)
                        {
                            if (info.bpp < 24)
                            {
                                psize = (info.offset - 14 - 24) / 3;
                            }
                        }
                        else
                        {
                            if (info.bpp < 16)
                            {
                                psize = (info.offset - 14 - info.hsz) >> 2;
                            }
                        }
                        s.img_n = (ma != 0) ? 4 : 3;
                        if ((req_comp != 0) && (req_comp >= 3))
                        {
                            target = req_comp;
                        }
                        else
                        {
                            target = s.img_n;
                        }
                        if (stbi__mad3sizes_valid(target, (int)s.img_x, (int)s.img_y, 0) == 0)
                        {
                            return((byte *)(ulong)((stbi__err("too large") != 0) ? (byte *)null : null));
                        }
                        _out_ = (byte *)stbi__malloc_mad3(target, (int)s.img_x, (int)s.img_y, 0);
                        if (_out_ == null)
                        {
                            return((byte *)(ulong)((stbi__err("outofmem") != 0) ? (byte *)null : null));
                        }
                        if (info.bpp < 16)
                        {
                            var z = 0;
                            if ((psize == 0) || (psize > 256))
                            {
                                CRuntime.free(_out_);
                                return((byte *)(ulong)((stbi__err("invalid") != 0) ? (byte *)null : null));
                            }
                            for (i = 0; i < psize; ++i)
                            {
                                pal[i * 4 + 2] = stbi__get8(s);
                                pal[i * 4 + 1] = stbi__get8(s);
                                pal[i * 4 + 0] = stbi__get8(s);
                                if (info.hsz != 12)
                                {
                                    stbi__get8(s);
                                }
                                pal[i * 4 + 3] = 255;
                            }
                            stbi__skip(s, info.offset - 14 - info.hsz - psize * ((info.hsz == 12) ? 3 : 4));
                            if (info.bpp == 1)
                            {
                                width = (int)((s.img_x + 7) >> 3);
                            }
                            else
                            {
                                if (info.bpp == 4)
                                {
                                    width = (int)((s.img_x + 1) >> 1);
                                }
                                else
                                {
                                    if (info.bpp == 8)
                                    {
                                        width = (int)s.img_x;
                                    }
                                    else
                                    {
                                        CRuntime.free(_out_);
                                        return((byte *)(ulong)((stbi__err("bad bpp") != 0) ? (byte *)null : null));
                                    }
                                }
                            }
                            pad = -width & 3;
                            if (info.bpp == 1)
                            {
                                for (j = 0; j < (int)s.img_y; ++j)
                                {
                                    var bit_offset = 7;
                                    var v          = (int)stbi__get8(s);
                                    for (i = 0; i < (int)s.img_x; ++i)
                                    {
                                        var color = (v >> bit_offset) & 0x1;
                                        _out_[z++] = pal[color * 4 + 0];
                                        _out_[z++] = pal[color * 4 + 1];
                                        _out_[z++] = pal[color * 4 + 2];
                                        if (target == 4)
                                        {
                                            _out_[z++] = 255;
                                        }
                                        if ((i + 1) == (int)s.img_x)
                                        {
                                            break;
                                        }
                                        if ((--bit_offset) < 0)
                                        {
                                            bit_offset = 7;
                                            v          = stbi__get8(s);
                                        }
                                    }
                                    stbi__skip(s, pad);
                                }
                            }
                            else
                            {
                                for (j = 0; j < (int)s.img_y; ++j)
                                {
                                    for (i = 0; i < (int)s.img_x; i += 2)
                                    {
                                        var v  = (int)stbi__get8(s);
                                        var v2 = 0;
                                        if (info.bpp == 4)
                                        {
                                            v2  = v & 15;
                                            v >>= 4;
                                        }
                                        _out_[z++] = pal[v * 4 + 0];
                                        _out_[z++] = pal[v * 4 + 1];
                                        _out_[z++] = pal[v * 4 + 2];
                                        if (target == 4)
                                        {
                                            _out_[z++] = 255;
                                        }
                                        if ((i + 1) == (int)s.img_x)
                                        {
                                            break;
                                        }
                                        v          = (info.bpp == 8) ? stbi__get8(s) : v2;
                                        _out_[z++] = pal[v * 4 + 0];
                                        _out_[z++] = pal[v * 4 + 1];
                                        _out_[z++] = pal[v * 4 + 2];
                                        if (target == 4)
                                        {
                                            _out_[z++] = 255;
                                        }
                                    }
                                    stbi__skip(s, pad);
                                }
                            }
                        }
                        else
                        {
                            var rshift = 0;
                            var gshift = 0;
                            var bshift = 0;
                            var ashift = 0;
                            var rcount = 0;
                            var gcount = 0;
                            var bcount = 0;
                            var acount = 0;
                            var z      = 0;
                            var easy   = 0;
                            stbi__skip(s, info.offset - 14 - info.hsz);
                            if (info.bpp == 24)
                            {
                                width = (int)(3 * s.img_x);
                            }
                            else
                            {
                                if (info.bpp == 16)
                                {
                                    width = (int)(2 * s.img_x);
                                }
                                else
                                {
                                    width = 0;
                                }
                            }
                            pad = -width & 3;
                            if (info.bpp == 24)
                            {
                                easy = 1;
                            }
                            else
                            {
                                if (info.bpp == 32)
                                {
                                    if ((mb == 0xff) && (mg == 0xff00) && (mr == 0x00ff0000) && (ma == 0xff000000))
                                    {
                                        easy = 2;
                                    }
                                }
                            }
                            if (easy == 0)
                            {
                                if ((mr == 0) || (mg == 0) || (mb == 0))
                                {
                                    CRuntime.free(_out_);
                                    return((byte *)(ulong)((stbi__err("bad masks") != 0) ? (byte *)null : null));
                                }
                                rshift = stbi__high_bit(mr) - 7;
                                rcount = stbi__bitcount(mr);
                                gshift = stbi__high_bit(mg) - 7;
                                gcount = stbi__bitcount(mg);
                                bshift = stbi__high_bit(mb) - 7;
                                bcount = stbi__bitcount(mb);
                                ashift = stbi__high_bit(ma) - 7;
                                acount = stbi__bitcount(ma);
                            }
                            for (j = 0; j < (int)s.img_y; ++j)
                            {
                                if (easy != 0)
                                {
                                    for (i = 0; i < (int)s.img_x; ++i)
                                    {
                                        byte a = 0;
                                        _out_[z + 2] = stbi__get8(s);
                                        _out_[z + 1] = stbi__get8(s);
                                        _out_[z + 0] = stbi__get8(s);
                                        z           += 3;
                                        a            = (byte)((easy == 2) ? stbi__get8(s) : 255);
                                        all_a       |= a;
                                        if (target == 4)
                                        {
                                            _out_[z++] = a;
                                        }
                                    }
                                }
                                else
                                {
                                    var bpp = info.bpp;
                                    for (i = 0; i < (int)s.img_x; ++i)
                                    {
                                        var  v = (bpp == 16) ? (uint)stbi__get16le(s) : stbi__get32le(s);
                                        uint a = 0;
                                        _out_[z++] = (byte)(stbi__shiftsigned(v & mr, rshift, rcount) & 255);
                                        _out_[z++] = (byte)(stbi__shiftsigned(v & mg, gshift, gcount) & 255);
                                        _out_[z++] = (byte)(stbi__shiftsigned(v & mb, bshift, bcount) & 255);
                                        a          = (uint)((ma != 0) ? stbi__shiftsigned(v & ma, ashift, acount) : 255);
                                        all_a     |= a;
                                        if (target == 4)
                                        {
                                            _out_[z++] = (byte)(a & 255);
                                        }
                                    }
                                }
                                stbi__skip(s, pad);
                            }
                        }
                        if ((target == 4) && (all_a == 0))
                        {
                            for (i = (int)(4 * s.img_x * s.img_y - 1); i >= 0; i -= 4)
                            {
                                _out_[i] = 255;
                            }
                        }
                        if (flip_vertically != 0)
                        {
                            byte t = 0;
                            for (j = 0; j < (int)s.img_y >> 1; ++j)
                            {
                                var p1 = _out_ + j * s.img_x * target;
                                var p2 = _out_ + (s.img_y - 1 - j) * s.img_x * target;
                                for (i = 0; i < (int)s.img_x * target; ++i)
                                {
                                    t     = p1[i];
                                    p1[i] = p2[i];
                                    p2[i] = t;
                                }
                            }
                        }
                        if ((req_comp != 0) && (req_comp != target))
                        {
                            _out_ = stbi__convert_format(_out_, target, req_comp, s.img_x, s.img_y);
                            if (_out_ == null)
                            {
                                return(_out_);
                            }
                        }
                        *x = (int)s.img_x;
                        *y = (int)s.img_y;
                        if (comp != null)
                        {
                            *comp = s.img_n;
                        }
                        return(_out_);
                    }