1// tImageWEBP.h 
2// 
3// This knows how to load WebPs. It knows the details of the webp file format and loads the data into multiple tPixel 
4// arrays, one for each frame (WebPs may be animated). These arrays may be 'stolen' by tPictures. 
5// 
6// Copyright (c) 2020 Tristan Grimmer. 
7// Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby 
8// granted, provided that the above copyright notice and this permission notice appear in all copies. 
9// 
10// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL 
11// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, 
12// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 
13// AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 
14// PERFORMANCE OF THIS SOFTWARE. 
15 
16#pragma once 
17#include <Foundation/tString.h> 
18#include <Math/tColour.h> 
19#include <Image/tPixelFormat.h> 
20namespace tImage 
21{ 
22 
23 
24class tImageWEBP 
25{ 
26public: 
27 // Creates an invalid tImageWEBP. You must call Load manually. 
28 tImageWEBP() { } 
29 tImageWEBP(const tString& webpFile) { Load(webpFile); } 
30 
31 virtual ~tImageWEBP() { Clear(); } 
32 
33 // Clears the current tImageWEBP before loading. If false returned object is invalid. 
34 bool Load(const tString& webpFile); 
35 
36 // After this call no memory will be consumed by the object and it will be invalid. 
37 void Clear(); 
38 bool IsValid() const { return (GetNumFrames() >= 1); } 
39 int GetNumFrames() const { return Frames.GetNumItems(); } 
40 
41 struct Frame : public tLink<Frame> 
42 { 
43 int Width = 0; 
44 int Height = 0; 
45 tPixel* Pixels = nullptr; 
46 float Duration = 0.0f; // Frame duration in seconds. Converted from the WebPs 1ms count. 
47 tPixelFormat SrcPixelFormat = tPixelFormat::Invalid; 
48 }; 
49 
50 // After this call you are the owner of the frame and must eventually delete it. The frame you stole will no 
51 // longer be a valid frame of the tImageWEBP, but the remaining ones will still be valid. 
52 Frame* StealFrame(int frameNum); 
53 Frame* GetFrame(int frameNum); 
54 tPixelFormat SrcPixelFormat = tPixelFormat::Invalid; 
55 
56private: 
57 tList<Frame> Frames; 
58}; 
59 
60 
61// Implementation only below. 
62 
63 
64inline tImageWEBP::Frame* tImage::tImageWEBP::StealFrame(int frameNum) 
65{ 
66 Frame* f = GetFrame(frameNum); 
67 if (!f) 
68 return nullptr; 
69 
70 return Frames.Remove(f); 
71} 
72 
73 
74inline tImageWEBP::Frame* tImage::tImageWEBP::GetFrame(int frameNum) 
75{ 
76 if ((frameNum >= Frames.GetNumItems()) || (frameNum < 0)) 
77 return nullptr; 
78 
79 Frame* f = Frames.First(); 
80 while (frameNum--) 
81 f = f->Next(); 
82 
83 return f; 
84} 
85 
86 
87inline void tImageWEBP::Clear() 
88{ 
89 while (Frame* frame = Frames.Remove()) 
90 { 
91 delete[] frame->Pixels; 
92 delete frame; 
93 } 
94 
95 SrcPixelFormat = tPixelFormat::Invalid; 
96} 
97 
98 
99} 
100