Rack/src/app/Knob.cpp

#include <app/Knob.hpp>
#include <app.hpp>
#include <app/Scene.hpp>
#include <random.hpp>
#include <history.hpp>


namespace rack {
namespace app {


static const float KNOB_SENSITIVITY = 0.0015f;


void Knob::onHover(const event::Hover& e) {
	math::Vec c = box.size.div(2);
	float dist = e.pos.minus(c).norm();
	if (dist <= c.x) {
		ParamWidget::onHover(e);
	}
}

void Knob::onButton(const event::Button& e) {
	math::Vec c = box.size.div(2);
	float dist = e.pos.minus(c).norm();
	if (dist <= c.x) {
		ParamWidget::onButton(e);
	}
}

void Knob::onDragStart(const event::DragStart& e) {
	if (e.button != GLFW_MOUSE_BUTTON_LEFT)
		return;

	if (paramQuantity) {
		oldValue = paramQuantity->getSmoothValue();
		if (snap) {
			snapValue = paramQuantity->getValue();
		}
	}

	APP->window->cursorLock();
}

void Knob::onDragEnd(const event::DragEnd& e) {
	if (e.button != GLFW_MOUSE_BUTTON_LEFT)
		return;

	APP->window->cursorUnlock();

	if (paramQuantity) {
		float newValue = paramQuantity->getSmoothValue();
		if (oldValue != newValue) {
			// Push ParamChange history action
			history::ParamChange* h = new history::ParamChange;
			h->name = "move knob";
			h->moduleId = paramQuantity->module->id;
			h->paramId = paramQuantity->paramId;
			h->oldValue = oldValue;
			h->newValue = newValue;
			APP->history->push(h);
		}
	}
}

void Knob::onDragMove(const event::DragMove& e) {
	if (e.button != GLFW_MOUSE_BUTTON_LEFT)
		return;

	if (paramQuantity) {
		float range;
		if (paramQuantity->isBounded()) {
			range = paramQuantity->getRange();
		}
		else {
			// Continuous encoders scale as if their limits are +/-1
			range = 2.f;
		}
		float delta = (horizontal ? e.mouseDelta.x : -e.mouseDelta.y);
		delta *= KNOB_SENSITIVITY;
		delta *= speed;
		delta *= range;

		// Drag slower if mod is held
		int mods = APP->window->getMods();
		if ((mods & RACK_MOD_MASK) == RACK_MOD_CTRL) {
			delta /= 16.f;
		}
		// Drag even slower if mod+shift is held
		if ((mods & RACK_MOD_MASK) == (RACK_MOD_CTRL | GLFW_MOD_SHIFT)) {
			delta /= 256.f;
		}

		if (snap) {
			snapValue += delta;
			snapValue = math::clamp(snapValue, paramQuantity->getMinValue(), paramQuantity->getMaxValue());
			paramQuantity->setValue(std::round(snapValue));
		}
		else if (smooth) {
			paramQuantity->setSmoothValue(paramQuantity->getSmoothValue() + delta);
		}
		else {
			paramQuantity->setValue(paramQuantity->getValue() + delta);
		}
	}

	ParamWidget::onDragMove(e);
}

void Knob::reset() {
	if (paramQuantity && paramQuantity->isBounded()) {
		paramQuantity->reset();
		oldValue = snapValue = paramQuantity->getValue();
	}
}

void Knob::randomize() {
	if (paramQuantity && paramQuantity->isBounded()) {
		float value = math::rescale(random::uniform(), 0.f, 1.f, paramQuantity->getMinValue(), paramQuantity->getMaxValue());
		if (snap)
			value = std::round(value);
		paramQuantity->setValue(value);
		oldValue = snapValue = paramQuantity->getValue();
	}
}


} // namespace app
} // namespace rack