Add osgemscripten example

examples/osgemscripten/functions.h

@@ -0,0 +1,76 @@
+/* OpenSceneGraph example, osgemscripten.
+*
+*  Permission is hereby granted, free of charge, to any person obtaining a copy
+*  of this software and associated documentation files (the "Software"), to deal
+*  in the Software without restriction, including without limitation the rights
+*  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+*  copies of the Software, and to permit persons to whom the Software is
+*  furnished to do so, subject to the following conditions:
+*
+*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+*  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+*  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+*  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+*  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+*  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+*  THE SOFTWARE.
+*/
+
+#ifndef OSGEMSCRIPTEN_FUNCTIONS_H
+#define OSGEMSCRIPTEN_FUNCTIONS_H
+
+#include <osg/Notify>
+
+// Convert NotifySeverity enum value to string.
+std::string logLevelToString(osg::NotifySeverity severity)
+{
+    switch (severity)
+    {
+        case osg::DEBUG_FP:
+            // Verbose.
+            return "V";
+        case osg::DEBUG_INFO:
+            // Debug.
+            return "D";
+        case osg::NOTICE:
+        case osg::INFO:
+            // Info.
+            return "I";
+        case osg::WARN:
+            // Warning.
+            return "W";
+        case osg::FATAL:
+        case osg::ALWAYS:
+            // Error.
+            return "E";
+    }
+}
+
+#include <osg/Program>
+
+// Fragment shader to display everything in red colour.
+static const char shaderFragment[] =
+    "void main() {                             \n"
+    "  gl_FragColor = vec4(0.5, 0.3, 0.3, 1.0);\n"
+    "}                                         \n";
+// Geometry shader to pass geometry vertices to fragment shader.
+static const char shaderVertex[] =
+    "void main() {                                              \n"
+    "  gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;  \n"
+    "}                                                          \n";
+
+osg::Program *createShaderProgram(
+    const std::string &vertexShader,
+    const std::string &fragmentShader)
+{
+    // Load shaders.
+    osg::Shader *vs = new osg::Shader(osg::Shader::VERTEX, vertexShader);
+    osg::Shader *fs = new osg::Shader(osg::Shader::FRAGMENT, fragmentShader);
+    // Compile shaders and compose shader program.
+    osg::Program *prog = new osg::Program;
+    prog->addShader(vs);
+    prog->addShader(fs);
+    return prog;
+}
+
+#endif // OSGEMSCRIPTEN_FUNCTIONS_H