Merge branch 'features/module-pushing' into features/experiments

# Conflicts:
#	README.md

README.md

@@ -27,6 +27,11 @@ You can append a whole patch, or skip the first row of the patch you're appendin
 
 The skip first row feature lets you build a component with audio and test trigger modules in the first row that don't get added to the combined patch when you append it.
 
+# Experiment - module pushing
+
+Holding shift while moving a module left or right will push any other modules it hits out of the way.
+This lets you push a bunch of modules together to easily make space for another module.
+
 # Rack
 
 *Rack* is the engine for the VCV open-source virtual modular synthesizer.

include/app.hpp

@@ -187,8 +187,10 @@ struct RackWidget : OpaqueWidget {
 	void cloneModule(ModuleWidget *m);
 	/** Sets a module's box if non-colliding. Returns true if set */
 	bool requestModuleBox(ModuleWidget *m, Rect box);
+	std::vector<ModuleWidget*> getCollidingWidgets(ModuleWidget *m, Rect box);
 	/** Moves a module to the closest non-colliding position */
 	bool requestModuleBoxNearest(ModuleWidget *m, Rect box);
+	bool requestModuleBoxWithPush(ModuleWidget *m, Rect box);
 
 	void step() override;
 	void draw(NVGcontext *vg) override;

src/app/ModuleWidget.cpp

@@ -428,7 +428,11 @@ void ModuleWidget::onDragMove(EventDragMove &e) {
 	if (!gRackWidget->lockModules) {
 		Rect newBox = box;
 		newBox.pos = gRackWidget->lastMousePos.minus(dragPos);
-		gRackWidget->requestModuleBoxNearest(this, newBox);
+		if (windowIsShiftPressed()) {
+			gRackWidget->requestModuleBoxWithPush(this, newBox);
+		} else {
+			gRackWidget->requestModuleBoxNearest(this, newBox);
+		}
 	}
 }
 

src/app/RackWidget.cpp

@@ -503,6 +503,22 @@ bool RackWidget::requestModuleBox(ModuleWidget *m, Rect box) {
 	return true;
 }
 
+std::vector<ModuleWidget*> RackWidget::getCollidingWidgets(ModuleWidget *m, Rect box) {
+	std::vector<ModuleWidget*> result;
+
+	if (box.pos.x < 0 || box.pos.y < 0)
+		return result;
+
+	for (Widget *child2 : moduleContainer->children) {
+		if (m == child2) continue;
+		if (box.intersects(child2->box)) {
+			result.push_back(dynamic_cast<ModuleWidget*>(child2));
+		}
+	}
+
+	return result;
+}
+
 bool RackWidget::requestModuleBoxNearest(ModuleWidget *m, Rect box) {
 	// Create possible positions
 	int x0 = roundf(box.pos.x / RACK_GRID_WIDTH);
@@ -529,6 +545,56 @@ bool RackWidget::requestModuleBoxNearest(ModuleWidget *m, Rect box) {
 	return false;
 }
 
+bool RackWidget::requestModuleBoxWithPush(ModuleWidget *m, Rect box) {
+
+	// Find new position
+	int x0 = roundf(box.pos.x / RACK_GRID_WIDTH);
+	int y0 = roundf(box.pos.y / RACK_GRID_HEIGHT);
+
+	Rect newBox = box;
+	newBox.pos = Vec(x0 * RACK_GRID_WIDTH, y0 * RACK_GRID_HEIGHT);
+
+	// If moving out of bounds, fail the move
+	if (newBox.pos.x < 0.f || newBox.pos.y < 0.f) {
+		return false;
+	}
+
+	// If moving to another row, fail the push
+	if (m->box.pos.y != newBox.pos.y) {
+		return false;
+	}
+
+	bool toTheRight = m->box.pos.x < box.pos.x;
+	bool toTheLeft = !toTheRight;
+
+	auto colliders = getCollidingWidgets(m, newBox);
+	if (colliders.size() > (size_t)1) {
+		// Hitting too many other modules
+		return false;
+	}
+
+	for (auto colliding : colliders) {
+		Rect newCollidingBox = colliding->box;
+		if (toTheRight && colliding->box.pos.x > newBox.pos.x) {
+			newCollidingBox.pos.x = newBox.pos.x + newBox.size.x;
+		} else if (toTheLeft && colliding->box.pos.x <= newBox.pos.x) {
+			newCollidingBox.pos.x = newBox.pos.x - colliding->box.size.x;
+		} else {
+			// Moving module too fast - this module is trying to go the opposite way
+			return false;
+		}
+
+		if (!requestModuleBoxWithPush(colliding, newCollidingBox)) {
+			// We couldn't move a module out of the way - fail our move too
+			return false;
+		}
+	}
+
+	m->box = newBox;
+
+	return true;
+}
+
 void RackWidget::step() {
 	// Expand size to fit modules
 	Vec moduleSize = moduleContainer->getChildrenBoundingBox().getBottomRight();