ppc.backend.loaders.image.png source code

1 /**
2 Copyright (c) 2018 Clipsey (clipseypone@gmail.com)
3 
4 Permission is hereby granted, free of charge, to any person or organization
5 obtaining a copy of the software and accompanying documentation covered by
6 this license (the "Software") to use, reproduce, display, distribute,
7 execute, and transmit the Software, and to prepare derivative works of the
8 Software, and to permit third-parties to whom the Software is furnished to
9 do so, all subject to the following:
10 
11 The copyright notices in the Software and this entire statement, including
12 the above license grant, this restriction and the following disclaimer,
13 must be included in all copies of the Software, in whole or in part, and
14 all derivative works of the Software, unless such copies or derivative
15 works are solely in the form of machine-executable object code generated by
16 a source language processor.
17 
18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
21 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
22 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
23 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
24 DEALINGS IN THE SOFTWARE.
25 */
26 module ppc.backend.loaders.image.png;
27 import ppc.backend.cfile;
28 import ppc.types.image;
29 import imageformats;
30 
31 /// The bit depth of the png file
32 enum PNGDepth {
33     Bit16,
34     Bit8
35 }
36 
37 /// The type of color in the PNG file
38 enum ColorType : ubyte {
39     Grayscale       = 0,
40     RGB             = 2,
41     Indexed         = 3,
42     GrayscaleAlpha  = 4,
43     RGBA            = 6
44 }
45 
46 /// The compression method used in the PNG file
47 enum CompressionMethod : ubyte {
48     InflateDeflate = 0
49 }
50 
51 /// The filtering method used in the PNG file
52 enum FilterMethod : ubyte {
53     StandardAdaptive = 0
54 }
55 
56 /// The type of interlacing used in the PNG file
57 enum Interlace : ubyte {
58     None = 0,
59     Adam7 = 1
60 }
61 
62 /// PNG Header
63 struct PNGHeader {
64 public:
65     /// Width of image
66     int width;
67 
68     /// Height of image
69     int height;
70 
71     /// Bit depth of image
72     byte bitDepth;
73 
74     /// Color type of image
75     ColorType type;
76 
77     /// Compression method of image
78     CompressionMethod compressionMethod;
79 
80     /// Filtering method of image
81     FilterMethod filterMethod;
82 
83     /// Interlacing method of image
84     Interlace interlaceMethod;
85 }
86 
87 /// Read PNG header from memory
88 PNGHeader loadPNGHeader(MemFile file) {
89     return cast(PNGHeader)read_png_header_from_mem(file.arrayptr[0..file.length]);
90 }
91 
92 /**
93     Loads a PNG file from memory
94     loadPNG will automatically infer which bitdepth to load as (8 and 16 bit supported)
95 */
96 void loadPNG(MemFile file, Image* oimg) {
97     immutable PNGHeader header = loadPNGHeader(file);
98 
99     (*oimg).info.imageType = ImageType.PNG;
100 
101     // Load PNG with the right bit depth.
102     if (header.bitDepth >= 16) {
103         IFImage16 img = read_png16_from_mem(file.arrayptr[0..file.length]);
104         
105         (*oimg).info.colorFormat = cast(ColorFormat)img.c;
106         (*oimg).info.width = img.w;
107         (*oimg).info.height = img.h;
108         (*oimg).pixelData = cast(ubyte[])img.pixels;
109     } else {
110         IFImage img = read_png_from_mem(file.arrayptr[0..file.length]);
111         
112         (*oimg).info.colorFormat = cast(ColorFormat)img.c;
113         (*oimg).info.width = img.w;
114         (*oimg).info.height = img.h;
115         (*oimg).pixelData = img.pixels;
116     }
117 }
118 
119 /**
120     Loads a PNG file from memory
121     loadPNG will automatically infer which bitdepth to load as (8 and 16 bit supported)
122 */
123 Image loadPNG(MemFile file) {
124     Image oimg;
125     loadPNG(file, &oimg);
126     return oimg;
127 }
128 
129 /// Returns a writable PNG as a ubyte array
130 ubyte[] savePNG(Image img) {
131     ubyte[] o;
132     write_png_to_mem(img.width, img.height, o);
133     return o;
134 }