Mercurial > hg > orthanc-stone
comparison Framework/Scene2D/Internals/OpenGLFloatTextureProgram.cpp @ 591:b66ced2c43d4
OpenGLTextureProgram
author | Sebastien Jodogne <s.jodogne@gmail.com> |
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date | Fri, 26 Apr 2019 12:05:38 +0200 |
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children | bbe29efd3d1c |
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590:5430bcffba57 | 591:b66ced2c43d4 |
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1 /** | |
2 * Stone of Orthanc | |
3 * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics | |
4 * Department, University Hospital of Liege, Belgium | |
5 * Copyright (C) 2017-2019 Osimis S.A., Belgium | |
6 * | |
7 * This program is free software: you can redistribute it and/or | |
8 * modify it under the terms of the GNU Affero General Public License | |
9 * as published by the Free Software Foundation, either version 3 of | |
10 * the License, or (at your option) any later version. | |
11 * | |
12 * This program is distributed in the hope that it will be useful, but | |
13 * WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 * Affero General Public License for more details. | |
16 * | |
17 * You should have received a copy of the GNU Affero General Public License | |
18 * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
19 **/ | |
20 | |
21 | |
22 #include "OpenGLFloatTextureProgram.h" | |
23 | |
24 #include <Core/OrthancException.h> | |
25 #include <Core/Images/Image.h> | |
26 #include <Core/Images/ImageProcessing.h> | |
27 | |
28 | |
29 static const char* FRAGMENT_SHADER = | |
30 "uniform float u_offset; \n" | |
31 "uniform float u_slope; \n" | |
32 "uniform float u_windowCenter; \n" | |
33 "uniform float u_windowWidth; \n" | |
34 "uniform sampler2D u_texture; \n" | |
35 "varying vec2 v_texcoord; \n" | |
36 "void main() \n" | |
37 "{ \n" | |
38 " vec4 t = texture2D(u_texture, v_texcoord); \n" | |
39 " float v = (t.r * 256.0 + t.g) * 256.0; \n" | |
40 " v = v * u_slope + u_offset; \n" // (*) | |
41 " float a = u_windowCenter - u_windowWidth; \n" | |
42 " float dy = 1.0 / (2.0 * u_windowWidth); \n" | |
43 " if (v <= a) \n" | |
44 " v = 0.0; \n" | |
45 " else \n" | |
46 " { \n" | |
47 " v = (v - a) * dy; \n" | |
48 " if (v >= 1.0) \n" | |
49 " v = 1.0; \n" | |
50 " } \n" | |
51 " gl_FragColor = vec4(v, v, v, 1); \n" | |
52 "}"; | |
53 | |
54 | |
55 namespace OrthancStone | |
56 { | |
57 namespace Internals | |
58 { | |
59 OpenGLFloatTextureProgram::OpenGLFloatTextureProgram(OpenGL::IOpenGLContext& context) : | |
60 program_(context, FRAGMENT_SHADER) | |
61 { | |
62 } | |
63 | |
64 | |
65 OpenGLFloatTextureProgram::Data::Data(const Orthanc::ImageAccessor& texture, | |
66 bool isLinearInterpolation) | |
67 { | |
68 if (texture.GetFormat() != Orthanc::PixelFormat_Float32) | |
69 { | |
70 throw Orthanc::OrthancException(Orthanc::ErrorCode_IncompatibleImageFormat); | |
71 } | |
72 | |
73 float minValue, maxValue; | |
74 Orthanc::ImageProcessing::GetMinMaxFloatValue(minValue, maxValue, texture); | |
75 | |
76 offset_ = minValue; | |
77 | |
78 if (LinearAlgebra::IsCloseToZero(maxValue - minValue)) | |
79 { | |
80 slope_ = 1; | |
81 } | |
82 else | |
83 { | |
84 slope_ = (maxValue - minValue) / 65536.0f; | |
85 assert(!LinearAlgebra::IsCloseToZero(slope_)); | |
86 } | |
87 | |
88 const unsigned int width = texture.GetWidth(); | |
89 const unsigned int height = texture.GetHeight(); | |
90 | |
91 Orthanc::Image converted(Orthanc::PixelFormat_RGB24, width, height, true); | |
92 | |
93 for (unsigned int y = 0; y < height; y++) | |
94 { | |
95 const float *p = reinterpret_cast<const float*>(texture.GetConstRow(y)); | |
96 uint8_t *q = reinterpret_cast<uint8_t*>(converted.GetRow(y)); | |
97 | |
98 for (unsigned int x = 0; x < width; x++) | |
99 { | |
100 /** | |
101 * At (*), the floating-point "value" is reconstructed as | |
102 * "value = texture * slope + offset". | |
103 * <=> texture = (value - offset) / slope | |
104 **/ | |
105 | |
106 float texture = (*p - offset_) / slope_; | |
107 if (texture < 0) | |
108 { | |
109 texture = 0; | |
110 } | |
111 else if (texture >= 65535.0f) | |
112 { | |
113 texture = 65535.0f; | |
114 } | |
115 | |
116 uint16_t t = static_cast<uint16_t>(texture); | |
117 | |
118 q[0] = t / 256; // red | |
119 q[1] = t % 256; // green | |
120 q[2] = 0; // blue is unused | |
121 | |
122 p++; | |
123 q += 3; | |
124 } | |
125 } | |
126 | |
127 texture_.Load(converted, isLinearInterpolation); | |
128 } | |
129 | |
130 | |
131 void OpenGLFloatTextureProgram::Apply(Data& data, | |
132 const AffineTransform2D& transform, | |
133 float windowCenter, | |
134 float windowWidth) | |
135 { | |
136 OpenGLTextureProgram::Execution execution(program_, data.GetTexture(), transform); | |
137 | |
138 glUniform1f(execution.GetUniformLocation("u_slope"), data.GetSlope()); | |
139 glUniform1f(execution.GetUniformLocation("u_offset"), data.GetOffset()); | |
140 glUniform1f(execution.GetUniformLocation("u_windowCenter"), windowCenter); | |
141 glUniform1f(execution.GetUniformLocation("u_windowWidth"), windowWidth); | |
142 | |
143 execution.DrawTriangles(); | |
144 } | |
145 } | |
146 } |