1// tImagePNG.h 
2// 
3// This class knows how to load and save PNG files. It does zero processing of image data. It knows the details of the 
4// png file format and loads the data into a tPixel array. These tPixels may be 'stolen' by the tPicture's constructor 
5// if a png file is specified. After the array is stolen the tImagePNG is invalid. This is purely for performance. 
6// 
7// Copyright (c) 2020 Tristan Grimmer. 
8// Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby 
9// granted, provided that the above copyright notice and this permission notice appear in all copies. 
10// 
11// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL 
12// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, 
13// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 
14// AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 
15// PERFORMANCE OF THIS SOFTWARE. 
16 
17#pragma once 
18#include <Foundation/tString.h> 
19#include <Math/tColour.h> 
20#include <Image/tPixelFormat.h> 
21namespace tImage 
22{ 
23 
24 
25class tImagePNG 
26{ 
27public: 
28 // Creates an invalid tImagePNG. You must call Load manually. 
29 tImagePNG() { } 
30 
31 tImagePNG(const tString& pngFile) { Load(pngFile); } 
32 
33 // The data is copied out of pngFileInMemory. Go ahead and delete after if you want. 
34 tImagePNG(const uint8* pngFileInMemory, int numBytes) { Set(pngFileInMemory, numBytes); } 
35 
36 // This one sets from a supplied pixel array. If steal is true it takes ownership of the pixels pointer. Otherwise 
37 // it just copies the data out. 
38 tImagePNG(tPixel* pixels, int width, int height, bool steal = false) { Set(pixels, width, height, steal); } 
39 
40 virtual ~tImagePNG() { Clear(); } 
41 
42 // Clears the current tImagePNG before loading. Returns success. If false returned, object is invalid. 
43 bool Load(const tString& pngFile); 
44 bool Set(const uint8* pngFileInMemory, int numBytes); 
45 
46 // This one sets from a supplied pixel array. If steal is true it takes ownership of the pixels pointer. Otherwise 
47 // it just copies the data out. 
48 bool Set(tPixel*, int width, int height, bool steal = false); 
49 
50 // Saves the tImagePNG to the PNG file specified. The extension of filename must be ".png". Returns true on success. 
51 bool Save(const tString& pngFile) const; 
52 
53 // After this call no memory will be consumed by the object and it will be invalid. 
54 void Clear(); 
55 bool IsValid() const { return Pixels ? true : false; } 
56 
57 int GetWidth() const { return Width; } 
58 int GetHeight() const { return Height; } 
59 bool IsOpaque() const; 
60 
61 // After this call you are the owner of the pixels and must eventually delete[] them. This tImagePNG object is 
62 // invalid afterwards. 
63 tPixel* StealPixels(); 
64 tPixel* GetPixels() const { return Pixels; } 
65 tPixelFormat SrcPixelFormat = tPixelFormat::Invalid; 
66 
67private: 
68 int Width = 0; 
69 int Height = 0; 
70 tPixel* Pixels = nullptr; 
71}; 
72 
73 
74// Implementation below this line. 
75 
76 
77inline void tImagePNG::Clear() 
78{ 
79 Width = 0; 
80 Height = 0; 
81 delete[] Pixels; 
82 Pixels = nullptr; 
83 SrcPixelFormat = tPixelFormat::Invalid; 
84} 
85 
86 
87} 
88