MPO: add ability to disable an override

jme3-core/src/main/java/com/jme3/material/MatParamOverride.java

@@ -35,6 +35,8 @@ import com.jme3.shader.VarType;
 
 public final class MatParamOverride extends MatParam {
 
+    private boolean enabled = true;
+
     public MatParamOverride() {
         super();
     }
@@ -43,4 +45,36 @@ public final class MatParamOverride extends MatParam {
         super(type, name, value);
     }
 
+    @Override
+    public boolean equals(Object obj) {
+        return super.equals(obj) && this.enabled == ((MatParamOverride) obj).enabled;
+    }
+
+    @Override
+    public int hashCode() {
+        int hash = super.hashCode();
+        hash = 59 * hash + (enabled ? 1 : 0);
+        return hash;
+    }
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+
+    @Override
+    public void write(JmeExporter ex) throws IOException {
+        super.write(ex);
+        OutputCapsule oc = ex.getCapsule(this);
+        oc.write(enabled, "enabled", true);
+    }
+
+    @Override
+    public void read(JmeImporter im) throws IOException {
+        super.read(im);
+        InputCapsule ic = im.getCapsule(this);
+        enabled = ic.readBoolean("enabled", true);
+    }
 }

jme3-core/src/main/java/com/jme3/material/Material.java

@@ -792,7 +792,7 @@ public class Material implements CloneableSmartAsset, Cloneable, Savable {
             VarType type = override.getVarType();
 
             MatParam paramDef = def.getMaterialParam(override.getName());
-            if (paramDef == null || paramDef.getVarType() != type) {
+            if (paramDef == null || paramDef.getVarType() != type || !override.isEnabled()) {
                 continue;
             }
 

jme3-core/src/main/java/com/jme3/material/Technique.java

@@ -128,6 +128,9 @@ public final class Technique {
         dynamicDefines.setAll(paramDefines);
 
         for (MatParamOverride override : overrides) {
+            if (!override.isEnabled()) {
+                continue;
+            }
             Integer defineId = def.getShaderParamDefineId(override.name);
             if (defineId != null) {
                 if (def.getDefineIdType(defineId) == override.type) {

jme3-core/src/test/java/com/jme3/material/MaterialMatParamOverrideTest.java

@@ -55,7 +55,7 @@ import com.jme3.texture.Texture2D;
 import java.util.HashMap;
 import java.util.Map;
 
-public class TechniqueDefMatParamOverrideTest {
+public class MaterialMatParamOverrideTest {
 
     private static final HashSet<String> IGNORED_UNIFORMS = new HashSet<String>(
             Arrays.asList(new String[]{"m_ParallaxHeight", "m_Shininess"}));
@@ -119,6 +119,27 @@ public class TechniqueDefMatParamOverrideTest {
         outUniforms(uniform("AlphaDiscardThreshold", VarType.Float, 2.79f));
     }
 
+    @Test
+    public void testMpoDisable() {
+        material("Common/MatDefs/Light/Lighting.j3md");
+        inputMp(mpoFloat("AlphaDiscardThreshold", 3.12f));
+
+        MatParamOverride override = mpoFloat("AlphaDiscardThreshold", 2.79f);
+        inputMpo(override);
+        outDefines(def("DISCARD_ALPHA", VarType.Float, 2.79f));
+        outUniforms(uniform("AlphaDiscardThreshold", VarType.Float, 2.79f));
+
+        reset();
+        override.setEnabled(false);
+        outDefines(def("DISCARD_ALPHA", VarType.Float, 3.12f));
+        outUniforms(uniform("AlphaDiscardThreshold", VarType.Float, 3.12f));
+
+        reset();
+        override.setEnabled(true);
+        outDefines(def("DISCARD_ALPHA", VarType.Float, 2.79f));
+        outUniforms(uniform("AlphaDiscardThreshold", VarType.Float, 2.79f));
+    }
+
     @Test
     public void testIntMpoOnly() {
         material("Common/MatDefs/Light/Lighting.j3md");
@@ -349,13 +370,13 @@ public class TechniqueDefMatParamOverrideTest {
     private final NullRenderer renderer = new NullRenderer() {
         @Override
         public void setShader(Shader shader) {
-            TechniqueDefMatParamOverrideTest.this.usedShader = shader;
+            MaterialMatParamOverrideTest.this.usedShader = shader;
             evaluated = true;
         }
 
         @Override
         public void setTexture(int unit, Texture texture) {
-            TechniqueDefMatParamOverrideTest.this.usedTextures[unit] = texture;
+            MaterialMatParamOverrideTest.this.usedTextures[unit] = texture;
         }
     };
     private final RenderManager renderManager = new RenderManager(renderer);