Implement motion_changexby block

Author: adazem009

src/blocks/motionblocks.cpp

@@ -47,6 +47,7 @@ void MotionBlocks::registerBlocks(IEngine *engine)
     engine->addCompileFunction(this, "motion_goto", &compileGoTo);
     engine->addCompileFunction(this, "motion_glidesecstoxy", &compileGlideSecsToXY);
     engine->addCompileFunction(this, "motion_glideto", &compileGlideTo);
+    engine->addCompileFunction(this, "motion_changexby", &compileChangeXBy);
 }
 
 CompilerValue *MotionBlocks::compileMoveSteps(Compiler *compiler)
@@ -246,6 +247,16 @@ CompilerValue *MotionBlocks::compileGlideTo(Compiler *compiler)
     return nullptr;
 }
 
+CompilerValue *MotionBlocks::compileChangeXBy(Compiler *compiler)
+{
+    if (!compiler->target()->isStage()) {
+        CompilerValue *dx = compiler->addInput("DX");
+        compiler->addTargetFunctionCall("motion_changexby", Compiler::StaticType::Void, { Compiler::StaticType::Number }, { dx });
+    }
+
+    return nullptr;
+}
+
 extern "C" void motion_movesteps(Sprite *sprite, double steps)
 {
     double dir = sprite->direction();
@@ -510,6 +521,11 @@ extern "C" bool motion_is_target_valid(ExecutionContext *ctx, const StringPtr *n
     }
 }
 
+extern "C" void motion_changexby(Sprite *sprite, double dx)
+{
+    sprite->setX(sprite->x() + dx);
+}
+
 extern "C" double motion_xposition(Sprite *sprite)
 {
     return sprite->x();

src/blocks/motionblocks.h

@@ -26,6 +26,7 @@ class MotionBlocks : public IExtension
         static CompilerValue *compileGoTo(Compiler *compiler);
         static CompilerValue *compileGlideSecsToXY(Compiler *compiler);
         static CompilerValue *compileGlideTo(Compiler *compiler);
+        static CompilerValue *compileChangeXBy(Compiler *compiler);
 };
 
 } // namespace libscratchcpp

test/blocks/motion_blocks_test.cpp

@@ -1598,3 +1598,36 @@ TEST_F(MotionBlocksTest, GlideToSprite)
         ASSERT_TRUE(code->isFinished(ctx.get()));
     }
 }
+
+TEST_F(MotionBlocksTest, ChangeXBy)
+{
+    {
+        auto sprite = std::make_shared<Sprite>();
+        ScriptBuilder builder(m_extension.get(), m_engine, sprite);
+
+        builder.addBlock("motion_changexby");
+        builder.addValueInput("DX", 30.25);
+
+        sprite->setX(5.2);
+        sprite->setY(-0.25);
+        sprite->setDirection(-61.42);
+
+        builder.build();
+        builder.run();
+        ASSERT_EQ(sprite->x(), 35.45);
+        ASSERT_EQ(sprite->y(), -0.25);
+    }
+
+    m_engine->clear();
+
+    {
+        auto stage = std::make_shared<Stage>();
+        ScriptBuilder builder(m_extension.get(), m_engine, stage);
+
+        builder.addBlock("motion_changexby");
+        builder.addValueInput("DX", 30.25);
+
+        builder.build();
+        builder.run();
+    }
+}