Adds a test case to modify an existing mat def through the shader nodes api

jme3-examples/src/main/java/jme3test/material/TestShaderNodesModifApi.java

@@ -0,0 +1,84 @@
+package jme3test.material;
+
+import com.jme3.app.SimpleApplication;
+import com.jme3.material.*;
+import com.jme3.math.ColorRGBA;
+import com.jme3.scene.Geometry;
+import com.jme3.scene.VertexBuffer;
+import com.jme3.scene.shape.Box;
+import com.jme3.shader.*;
+import com.jme3.shader.builder.MaterialBuilder;
+import com.jme3.texture.Texture;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class TestShaderNodesModifApi extends SimpleApplication {
+
+    public static void main(String[] args) {
+        TestShaderNodesModifApi app = new TestShaderNodesModifApi();
+        app.start();
+    }
+
+    @Override
+    public void simpleInitApp() {
+        flyCam.setMoveSpeed(20);
+        Logger.getLogger("com.jme3").setLevel(Level.WARNING);
+        Box boxshape1 = new Box(1f, 1f, 1f);
+        Geometry cube = new Geometry("A Box", boxshape1);
+        Texture tex = assetManager.loadTexture("Interface/Logo/Monkey.jpg");
+
+        MaterialBuilder mb = new MaterialBuilder(assetManager,"jme3test/matdefs/test.j3md");
+        mb.addMatParam(VarType.Vector4, "Color2");
+        mb.addMatParam(VarType.Texture2D, "Texture");
+
+        mb.technique().inlineVertexNode("vec2","TexCoord", "%texIn")
+                .inputs(
+                        mb.map("texIn", VertexBuffer.Type.TexCoord)
+                );
+
+
+        mb.technique().inlineFragmentNode("vec4","TextureFetch","texture2D(%tex, %texCoord)")
+                .inputs(
+                        mb.map("tex", "MatParam.Texture"),
+                        mb.map("texCoord", "TexCoord.result")
+                ).outputs(
+                        mb.map("result", "Global.color")
+                );
+
+
+        mb.technique().addNode("ColorMult2", "ColorMult", "jme3test/matdefs/ColorMult.frag")
+        .inputs(
+                mb.map("color1", "ColorMult.result"),
+                mb.map("color2", "MatParam.Color2"),
+                mb.map("color3", "TextureFetch.result"))
+        .outputs(
+                mb.map("result", "Global.color")
+        );
+
+        // TODO we need a way to order the nodes. They could be sorted by scanning the inputs and outputs and building a node tree, then sort it with a topological sort,
+        // but that won't work in some cases when node output is the Global color or Global position. So we'd need a fallback to manually order the nodes.
+        // So as long as we implement the fallback... The sort is maybe not worth it.
+        // API could be mb.technique().moveNode("Node1").before("Node2") or after("Node2")...
+        // or something like mb.technique().setOrder("Node1", "Node2", etc...) but this would require the user to know all the existing nodes.
+        // or maybe both...
+
+        Material mat = mb.build();
+
+        mat.selectTechnique(TechniqueDef.DEFAULT_TECHNIQUE_NAME, renderManager);
+        Technique t = mat.getActiveTechnique();
+
+        for (Shader.ShaderSource shaderSource : t.getDef().getShader(assetManager, renderer.getCaps(), t.getDynamicDefines()).getSources()) {
+            System.out.println(shaderSource.getSource());
+        }
+
+        mat.setColor("Color", ColorRGBA.Yellow);
+        mat.setColor("Color2", ColorRGBA.Red);
+        mat.setTexture("Texture", tex);
+        cube.setMaterial(mat);
+        cube.move(0, 0, 0);
+        rootNode.attachChild(cube);
+
+
+    }
+}