From 14fa9b4c12f034a5146562a1244d7f93e1c3a988 Mon Sep 17 00:00:00 2001
From: Niklas Harrysson <niklas.harrysson@gmail.com>
Date: Mon, 1 Apr 2019 14:05:18 +0200
Subject: [PATCH] Added loading of material from source code. (#344)

---
 source/MaterialXView/Material.cpp | 24 +++++++++++++++++++++
 source/MaterialXView/Material.h   |  3 +++
 source/MaterialXView/Viewer.cpp   | 35 +++++++++++++++++++++++++++++++
 source/MaterialXView/Viewer.h     |  1 +
 4 files changed, 63 insertions(+)

diff --git a/source/MaterialXView/Material.cpp b/source/MaterialXView/Material.cpp
index 242c05d59a..c330252bac 100644
--- a/source/MaterialXView/Material.cpp
+++ b/source/MaterialXView/Material.cpp
@@ -190,6 +190,30 @@ bool Material::generateConstantShader(mx::GenContext& context,
     return _glShader->init(shaderName, vertexShader, pixelShader);
 }
 
+bool Material::loadSource(const mx::FilePath& vertexShaderFile, const mx::FilePath& pixelShaderFile, const std::string& shaderName, bool hasTransparency)
+{
+    _hasTransparency = hasTransparency;
+
+    if (!_glShader)
+    {
+        _glShader = std::make_shared<ng::GLShader>();
+    }
+
+    std::string vertexShader;
+    if (!mx::readFile(vertexShaderFile, vertexShader))
+    {
+        return false;
+    }
+
+    std::string pixelShader;
+    if (!mx::readFile(pixelShaderFile, pixelShader))
+    {
+        return false;
+    }
+
+    return _glShader->init(shaderName, vertexShader, pixelShader);
+}
+
 mx::ShaderPtr Material::generateSource(mx::GenContext& context, mx::ElementPtr elem)
 {
     if (!elem)
diff --git a/source/MaterialXView/Material.h b/source/MaterialXView/Material.h
index 7587081e1c..a9a5627cbc 100644
--- a/source/MaterialXView/Material.h
+++ b/source/MaterialXView/Material.h
@@ -73,6 +73,9 @@ class Material
         _udim = val;
     }
 
+    /// Load shader source from file.
+    bool loadSource(const mx::FilePath& vertexStage, const mx::FilePath& pixelStage, const std::string& shaderName, bool hasTransparency);
+
     /// Generate shader source for a given element and generation context.
     mx::ShaderPtr generateSource(mx::GenContext& context, mx::ElementPtr elem);
 
diff --git a/source/MaterialXView/Viewer.cpp b/source/MaterialXView/Viewer.cpp
index ea7d69773c..eccf3686fe 100644
--- a/source/MaterialXView/Viewer.cpp
+++ b/source/MaterialXView/Viewer.cpp
@@ -741,6 +741,32 @@ void Viewer::saveActiveMaterialSource()
     }
 }
 
+void Viewer::loadActiveMaterialSource()
+{
+    try
+    {
+        MaterialPtr material = getSelectedMaterial();
+        mx::TypedElementPtr elem = material ? material->getElement() : nullptr;
+        if (elem)
+        {
+            std::string baseName = elem->getName();
+            std::string vertexShaderFile = _searchPath[0] / (baseName + "_vs.glsl");
+            std::string pixelShaderFile = _searchPath[0] / (baseName + "_ps.glsl");
+            // Ignore transparency for now as we can't know from the source code 
+            // if the shader is transparent or not.
+            if (material->loadSource(vertexShaderFile, pixelShaderFile, baseName, false))
+            {
+                assignMaterial(material, _geometryList[_selectedGeom]);
+            }
+        }
+    }
+    catch (std::exception& e)
+    {
+        new ng::MessageDialog(this, ng::MessageDialog::Type::Warning, "Cannot load source for material", e.what());
+    }
+}
+
+
 bool Viewer::keyboardEvent(int key, int scancode, int action, int modifiers)
 {
     if (Screen::keyboardEvent(key, scancode, action, modifiers))
@@ -790,6 +816,15 @@ bool Viewer::keyboardEvent(int key, int scancode, int action, int modifiers)
         return true;
     }
 
+    // Load a material previously saved to file.
+    // Editing the source files before loading gives a way to debug
+    // and experiment with shader source code.
+    if (key == GLFW_KEY_L && action == GLFW_PRESS)
+    {
+        loadActiveMaterialSource();
+        return true;
+    }
+
     // Allow left and right keys to cycle through the renderable elements
     if ((key == GLFW_KEY_RIGHT || key == GLFW_KEY_LEFT) && action == GLFW_PRESS)
     {
diff --git a/source/MaterialXView/Viewer.h b/source/MaterialXView/Viewer.h
index 20971f3a91..b0a6d7a1cb 100644
--- a/source/MaterialXView/Viewer.h
+++ b/source/MaterialXView/Viewer.h
@@ -61,6 +61,7 @@ class Viewer : public ng::Screen
     void setupLights(mx::DocumentPtr doc, const std::string& envRadiancePath, const std::string& envIrradiancePath);
     void initializeDocument(mx::DocumentPtr libraries);
     void saveActiveMaterialSource();
+    void loadActiveMaterialSource();
 
     /// Assign the given material to a geometry, or to all geometries if no
     /// target is specified.