restored previous renderer iteration for porting

app/render/backend/opengl/openglshader.cpp

@@ -1,5 +1,7 @@
 #include "openglshader.h"
 
+#include <QOpenGLExtraFunctions>
+
 OpenGLShader::OpenGLShader()
 {
 
@@ -17,6 +19,117 @@ OpenGLShaderPtr OpenGLShader::CreateDefault(const QString &function_name, const
   return program;
 }
 
+// copied from source code to OCIODisplay
+const int OCIO_LUT3D_EDGE_SIZE = 32;
+
+// copied from source code to OCIODisplay, expanded from 3*LUT3D_EDGE_SIZE*LUT3D_EDGE_SIZE*LUT3D_EDGE_SIZE
+const int OCIO_NUM_3D_ENTRIES = 98304;
+
+OpenGLShaderPtr OpenGLShader::CreateOCIO(QOpenGLContext* ctx,
+                                         GLuint& lut_texture,
+                                         OCIO::ConstProcessorRcPtr processor,
+                                         bool alpha_is_associated)
+{
+
+  QOpenGLExtraFunctions* xf = ctx->extraFunctions();
+
+  // Create LUT texture
+  xf->glGenTextures(1, &lut_texture);
+
+  // Bind LUT
+  xf->glBindTexture(GL_TEXTURE_3D, lut_texture);
+
+  // Set texture parameters
+  xf->glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  xf->glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+  xf->glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+  xf->glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+  xf->glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+
+  // Allocate storage for texture
+  xf->glTexImage3D(GL_TEXTURE_3D, 0, GL_RGB16F_ARB,
+                   OCIO_LUT3D_EDGE_SIZE, OCIO_LUT3D_EDGE_SIZE, OCIO_LUT3D_EDGE_SIZE,
+                   0, GL_RGB,GL_FLOAT, nullptr);
+
+  //
+  // SET UP GLSL SHADER
+  //
+
+  OCIO::GpuShaderDesc shaderDesc;
+  const char* ocio_func_name = "OCIODisplay";
+  shaderDesc.setLanguage(OCIO::GPU_LANGUAGE_GLSL_1_0);
+  shaderDesc.setFunctionName(ocio_func_name);
+  shaderDesc.setLut3DEdgeLen(OCIO_LUT3D_EDGE_SIZE);
+
+  //
+  // COMPUTE 3D LUT
+  //
+
+  GLfloat* ocio_lut_data = new GLfloat[OCIO_NUM_3D_ENTRIES];
+  processor->getGpuLut3D(ocio_lut_data, shaderDesc);
+
+  // Upload LUT data to texture
+  xf->glTexSubImage3D(GL_TEXTURE_3D, 0,
+                      0, 0, 0,
+                      OCIO_LUT3D_EDGE_SIZE, OCIO_LUT3D_EDGE_SIZE, OCIO_LUT3D_EDGE_SIZE,
+                      GL_RGB, GL_FLOAT, ocio_lut_data);
+
+  delete [] ocio_lut_data;
+
+  // Create OCIO shader code
+  QString shader_text(processor->getGpuShaderText(shaderDesc));
+
+  QString shader_call;
+
+  // Enforce alpha association
+  if (alpha_is_associated) {
+
+    // If alpha is already associated, we'll need to disassociate and reassociate
+    shader_text.append("\n");
+
+    QString disassociate_func_name = "disassoc";
+    shader_text.append(CodeAlphaDisassociate(disassociate_func_name));
+
+    QString reassociate_func_name = "reassoc";
+    shader_text.append(CodeAlphaReassociate(reassociate_func_name));
+
+    // Make OCIO call pass through disassociate and reassociate function
+    shader_call = QString("%3(%1(%2(col), tex2));").arg(ocio_func_name,
+                                                        disassociate_func_name,
+                                                        reassociate_func_name);
+
+  } else {
+
+    // If alpha is not already associated, we can just associate after OCIO
+
+    // Add associate function
+    QString associate_func_name = "assoc";
+    shader_text.append(CodeAlphaAssociate(associate_func_name));
+
+    // Make OCIO call pass through associate function
+    shader_call = QString("%2(%1(col, tex2));").arg(ocio_func_name, associate_func_name);
+
+  }
+
+  // Add process() function, which GetPipeline() will call if specified
+  QString process_function_name = "process";
+  shader_text.append(QString("\n"
+                             "uniform sampler3D tex2;\n"
+                             "\n"
+                             "vec4 %2(vec4 col) {\n"
+                             "  return %1\n"
+                             "}\n").arg(shader_call, process_function_name));
+
+
+  // Get pipeline-based shader to inject OCIO shader into
+  OpenGLShaderPtr shader = OpenGLShader::CreateDefault(process_function_name, shader_text);
+
+  // Release LUT
+  xf->glBindTexture(GL_TEXTURE_3D, 0);
+
+  return shader;
+}
+
 QString OpenGLShader::CodeDefaultFragment(const QString &function_name, const QString &shader_code)
 {
   QString frag_code = QStringLiteral("#version 110\n"