Mercurial > hg > orthanc-stone
diff 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 |
parents | |
children | bbe29efd3d1c |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Framework/Scene2D/Internals/OpenGLFloatTextureProgram.cpp Fri Apr 26 12:05:38 2019 +0200 @@ -0,0 +1,146 @@ +/** + * Stone of Orthanc + * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics + * Department, University Hospital of Liege, Belgium + * Copyright (C) 2017-2019 Osimis S.A., Belgium + * + * This program is free software: you can redistribute it and/or + * modify it under the terms of the GNU Affero General Public License + * as published by the Free Software Foundation, either version 3 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + **/ + + +#include "OpenGLFloatTextureProgram.h" + +#include <Core/OrthancException.h> +#include <Core/Images/Image.h> +#include <Core/Images/ImageProcessing.h> + + +static const char* FRAGMENT_SHADER = + "uniform float u_offset; \n" + "uniform float u_slope; \n" + "uniform float u_windowCenter; \n" + "uniform float u_windowWidth; \n" + "uniform sampler2D u_texture; \n" + "varying vec2 v_texcoord; \n" + "void main() \n" + "{ \n" + " vec4 t = texture2D(u_texture, v_texcoord); \n" + " float v = (t.r * 256.0 + t.g) * 256.0; \n" + " v = v * u_slope + u_offset; \n" // (*) + " float a = u_windowCenter - u_windowWidth; \n" + " float dy = 1.0 / (2.0 * u_windowWidth); \n" + " if (v <= a) \n" + " v = 0.0; \n" + " else \n" + " { \n" + " v = (v - a) * dy; \n" + " if (v >= 1.0) \n" + " v = 1.0; \n" + " } \n" + " gl_FragColor = vec4(v, v, v, 1); \n" + "}"; + + +namespace OrthancStone +{ + namespace Internals + { + OpenGLFloatTextureProgram::OpenGLFloatTextureProgram(OpenGL::IOpenGLContext& context) : + program_(context, FRAGMENT_SHADER) + { + } + + + OpenGLFloatTextureProgram::Data::Data(const Orthanc::ImageAccessor& texture, + bool isLinearInterpolation) + { + if (texture.GetFormat() != Orthanc::PixelFormat_Float32) + { + throw Orthanc::OrthancException(Orthanc::ErrorCode_IncompatibleImageFormat); + } + + float minValue, maxValue; + Orthanc::ImageProcessing::GetMinMaxFloatValue(minValue, maxValue, texture); + + offset_ = minValue; + + if (LinearAlgebra::IsCloseToZero(maxValue - minValue)) + { + slope_ = 1; + } + else + { + slope_ = (maxValue - minValue) / 65536.0f; + assert(!LinearAlgebra::IsCloseToZero(slope_)); + } + + const unsigned int width = texture.GetWidth(); + const unsigned int height = texture.GetHeight(); + + Orthanc::Image converted(Orthanc::PixelFormat_RGB24, width, height, true); + + for (unsigned int y = 0; y < height; y++) + { + const float *p = reinterpret_cast<const float*>(texture.GetConstRow(y)); + uint8_t *q = reinterpret_cast<uint8_t*>(converted.GetRow(y)); + + for (unsigned int x = 0; x < width; x++) + { + /** + * At (*), the floating-point "value" is reconstructed as + * "value = texture * slope + offset". + * <=> texture = (value - offset) / slope + **/ + + float texture = (*p - offset_) / slope_; + if (texture < 0) + { + texture = 0; + } + else if (texture >= 65535.0f) + { + texture = 65535.0f; + } + + uint16_t t = static_cast<uint16_t>(texture); + + q[0] = t / 256; // red + q[1] = t % 256; // green + q[2] = 0; // blue is unused + + p++; + q += 3; + } + } + + texture_.Load(converted, isLinearInterpolation); + } + + + void OpenGLFloatTextureProgram::Apply(Data& data, + const AffineTransform2D& transform, + float windowCenter, + float windowWidth) + { + OpenGLTextureProgram::Execution execution(program_, data.GetTexture(), transform); + + glUniform1f(execution.GetUniformLocation("u_slope"), data.GetSlope()); + glUniform1f(execution.GetUniformLocation("u_offset"), data.GetOffset()); + glUniform1f(execution.GetUniformLocation("u_windowCenter"), windowCenter); + glUniform1f(execution.GetUniformLocation("u_windowWidth"), windowWidth); + + execution.DrawTriangles(); + } + } +}