libgui|GLShaderBank: Including common shader sources

'include.vertex' and 'include.fragment' in a shader definition are now used to specify additional paths to common shader sources that should be included in the primary sources of the shader. Both include keys are expected to be specified as arrays of paths to text files.
skyjake · Mar 26, 2014 · bcaeaf9 · bcaeaf9
1 parent 27b0659
commit bcaeaf9
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Showing 3 changed files with 72 additions and 16 deletions.
diff --git a/doomsday/libgui/include/de/gui/glshader.h b/doomsday/libgui/include/de/gui/glshader.h
@@ -23,6 +23,7 @@
 #include <de/Error>
 #include <de/Counted>
 #include <de/Asset>
+#include <de/Block>
 #include <de/IByteArray>
 
 #include "libgui.h"
@@ -64,6 +65,18 @@ class LIBGUI_PUBLIC GLShader : public Counted, public Asset
 
     void recompile();
 
+    /**
+     * Prefixes a piece of shader source code to another shader source. This takes
+     * into account that certain elements must remain at the beginning of the source
+     * (#version).
+     *
+     * @param source  Main source where prefixing is done.
+     * @param prefix  Source to prefix in the beginning of @a source.
+     *
+     * @return The resulting combination.
+     */
+    static Block prefixToSource(Block const &source, Block const &prefix);
+
 private:
     DENG2_PRIVATE(d)
 };

diff --git a/doomsday/libgui/src/glshader.cpp b/doomsday/libgui/src/glshader.cpp
@@ -107,6 +107,23 @@ void GLShader::clear()
     d->release();
 }
 
+Block GLShader::prefixToSource(Block const &source, Block const &prefix)
+{
+    Block src = source;
+    int versionPos = src.indexOf("#version ");
+    if(versionPos >= 0)
+    {
+        // Append prefix after version.
+        int pos = src.indexOf('\n', versionPos);
+        src.insert(pos + 1, prefix);
+    }
+    else
+    {
+        src = prefix + src;
+    }
+    return src;
+}
+
 void GLShader::compile(Type shaderType, IByteArray const &source)
 {
 #ifndef LIBGUI_GLES2
@@ -126,18 +143,7 @@ void GLShader::compile(Type shaderType, IByteArray const &source)
 
     // Prepare the shader source. This would be the time to substitute any
     // remaining symbols in the shader source.
-    Block src = source;
-    int versionPos = src.indexOf("#version ");
-    if(versionPos >= 0)
-    {
-        // Append prefix after version.
-        int pos = src.indexOf('\n', versionPos);
-        src.insert(pos + 1, prefix);
-    }
-    else
-    {
-        src = prefix + src;
-    }
+    Block src = prefixToSource(source, prefix);
     src.append('\0');
 
     char const *srcPtr = src.constData();

diff --git a/doomsday/libgui/src/glshaderbank.cpp b/doomsday/libgui/src/glshaderbank.cpp
@@ -22,6 +22,7 @@
 
 #include <de/App>
 #include <de/ScriptedInfo>
+#include <de/ArrayValue>
 #include <de/ByteArrayFile>
 #include <de/math.h>
 
@@ -34,16 +35,36 @@ DENG2_PIMPL(GLShaderBank)
     struct Source : public ISource
     {
         /// Information about a shader source.
-        struct ShaderSource {
+        struct ShaderSource
+        {
             String source;
-            enum Type {
+            enum Type
+            {
                 FilePath,
                 ShaderSourceText
             };
             Type type;
 
             ShaderSource(String const &str = "", Type t = ShaderSourceText)
-                : source(str), type(t) {}
+                : source(str), type(t) {}            
+
+            void convertToSourceText()
+            {
+                if(type == FilePath)
+                {
+                    source = String::fromLatin1(Block(App::rootFolder().locate<File const>(source)));
+                    type = ShaderSourceText;
+                }
+            }
+
+            void insertFromFile(String const &path)
+            {
+                convertToSourceText();
+                source += "\n";
+                Block combo = GLShader::prefixToSource(source.toLatin1(),
+                        Block(App::rootFolder().locate<File const>(path)));
+                source = String::fromLatin1(combo);
+            }
         };
 
         GLShaderBank &bank;
@@ -56,7 +77,7 @@ DENG2_PIMPL(GLShaderBank)
 
         Time sourceModifiedAt(ShaderSource const &src) const
         {
-            if(src.type == ShaderSource::FilePath)
+            if(src.type == ShaderSource::FilePath && !src.source.isEmpty())
             {
                 return App::rootFolder().locate<File const>(src.source).status().modifiedAt;
             }
@@ -206,6 +227,22 @@ Bank::ISource *GLShaderBank::newSourceFromInfo(String const &id)
         frag = ShaderSource(d->relativeToPath / def["path"] + ".fsh", ShaderSource::FilePath);
     }
 
+    // Additional shaders to append to the main source.
+    if(def.has("include.vertex"))
+    {
+        DENG2_FOR_EACH_CONST(ArrayValue::Elements, i, def["include.vertex"].value().as<ArrayValue>().elements())
+        {
+            vtx.insertFromFile(d->relativeToPath / (*i)->asText());
+        }
+    }
+    if(def.has("include.fragment"))
+    {
+        DENG2_FOR_EACH_CONST(ArrayValue::Elements, i, def["include.fragment"].value().as<ArrayValue>().elements())
+        {
+            frag.insertFromFile(d->relativeToPath / (*i)->asText());
+        }
+    }
+
     return new Source(*this, vtx, frag);
 }