diff Framework/Scene2D/Internals/OpenGLTextureProgram.cpp @ 591:b66ced2c43d4

OpenGLTextureProgram
author Sebastien Jodogne <s.jodogne@gmail.com>
date Fri, 26 Apr 2019 12:05:38 +0200
parents
children e3f21a265be5
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Scene2D/Internals/OpenGLTextureProgram.cpp	Fri Apr 26 12:05:38 2019 +0200
@@ -0,0 +1,120 @@
+/**
+ * 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 "OpenGLTextureProgram.h"
+
+static const unsigned int COMPONENTS = 2;
+static const unsigned int COUNT = 6;  // 2 triangles in 2D
+
+static const char* VERTEX_SHADER = 
+  "attribute vec2 a_texcoord;             \n"
+  "attribute vec4 a_position;             \n"
+  "uniform mat4 u_matrix;                 \n"
+  "varying vec2 v_texcoord;               \n"
+  "void main()                            \n"
+  "{                                      \n"
+  "  gl_Position = u_matrix * a_position; \n"
+  "  v_texcoord = a_texcoord;             \n"
+  "}";
+
+
+namespace OrthancStone
+{
+  namespace Internals
+  {
+    void OpenGLTextureProgram::InitializeExecution(OpenGL::OpenGLTexture& texture,
+                                                   const AffineTransform2D& transform)
+    {
+      context_.MakeCurrent();
+      program_->Use();
+
+      AffineTransform2D scale = AffineTransform2D::CreateScaling
+        (texture.GetWidth(), texture.GetHeight());
+
+      AffineTransform2D t = AffineTransform2D::Combine(transform, scale);
+
+      float m[16];
+      t.ConvertToOpenGLMatrix(m, context_.GetCanvasWidth(), context_.GetCanvasHeight());
+
+      texture.Bind(program_->GetUniformLocation("u_texture"));
+      glUniformMatrix4fv(program_->GetUniformLocation("u_matrix"), 1, GL_FALSE, m);
+
+      glBindBuffer(GL_ARRAY_BUFFER, buffers_[0]);
+      glEnableVertexAttribArray(positionLocation_);
+      glVertexAttribPointer(positionLocation_, COMPONENTS, GL_FLOAT, GL_FALSE, 0, 0);
+
+      glBindBuffer(GL_ARRAY_BUFFER, buffers_[1]);
+      glEnableVertexAttribArray(textureLocation_);
+      glVertexAttribPointer(textureLocation_, COMPONENTS, GL_FLOAT, GL_FALSE, 0, 0);
+    }
+
+    
+    void OpenGLTextureProgram::FinalizeExecution()
+    {
+      glDisableVertexAttribArray(positionLocation_);
+      glDisableVertexAttribArray(textureLocation_);
+    }
+
+    
+    OpenGLTextureProgram::OpenGLTextureProgram(OpenGL::IOpenGLContext& context,
+                                               const char* fragmentShader) :
+      context_(context)
+    {
+      static const float POSITIONS[COMPONENTS * COUNT] = {
+        0, 0,
+        0, 1,
+        1, 0,
+        1, 0,
+        0, 1,
+        1, 1
+      };
+        
+      context_.MakeCurrent();
+
+      program_.reset(new OpenGL::OpenGLProgram);
+      program_->CompileShaders(VERTEX_SHADER, fragmentShader);
+
+      positionLocation_ = program_->GetAttributeLocation("a_position");
+      textureLocation_ = program_->GetAttributeLocation("a_texcoord");
+
+      glGenBuffers(2, buffers_);
+
+      glBindBuffer(GL_ARRAY_BUFFER, buffers_[0]);
+      glBufferData(GL_ARRAY_BUFFER, sizeof(float) * COMPONENTS * COUNT, POSITIONS, GL_STATIC_DRAW);
+
+      glBindBuffer(GL_ARRAY_BUFFER, buffers_[1]);
+      glBufferData(GL_ARRAY_BUFFER, sizeof(float) * COMPONENTS * COUNT, POSITIONS, GL_STATIC_DRAW);
+    }
+
+
+    OpenGLTextureProgram::~OpenGLTextureProgram()
+    {
+      context_.MakeCurrent();
+      glDeleteBuffers(2, buffers_);
+    }
+
+
+    void OpenGLTextureProgram::Execution::DrawTriangles()
+    {
+      glDrawArrays(GL_TRIANGLES, 0, COUNT);
+    }
+  }
+}