Fix offset UI origin, UIValue operators, Add utils

src/kekengine/cpp/common/engine.cpp

@@ -280,7 +280,7 @@ int start() {
 		prevTime = time;
 
 		for(UIElement *uiEl : kekData.ui->elements) {
-			UIPoint pos = uiEl->getPosition();
+			UIPoint pos = uiEl->getScreenPosition();
 			uiEl->drawAll(pos, uiProjection);
 		}
 

src/kekengine/cpp/ui/ui.cpp

@@ -7,32 +7,6 @@
 
 namespace kek {
 
-constexpr UIValue &UIValue::operator+=(const UIValue& rhs) {
-	this->pixels += rhs.pixels;
-	this->parentWidth += rhs.parentWidth;
-	this->parentHeight += rhs.parentHeight;
-	this->screenWidth += rhs.screenWidth;
-	this->screenHeight += rhs.screenHeight;
-	return *this;
-}
-
-constexpr UIValue &UIValue::operator-=(const UIValue& rhs) {
-	this->pixels -= rhs.pixels;
-	this->parentWidth -= rhs.parentWidth;
-	this->parentHeight -= rhs.parentHeight;
-	this->screenWidth -= rhs.screenWidth;
-	this->screenHeight -= rhs.screenHeight;
-	return *this;
-}
-
-constexpr UIValue operator+(const UIValue& lhs, const UIValue& rhs) {
-	return UIValue(lhs) += rhs;
-}
-
-constexpr UIValue operator-(const UIValue& lhs, const UIValue& rhs) {
-	return UIValue(lhs) -= rhs;
-}
-
 UIElement::UIElement(UIValue x, UIValue y): x(x), y(y) {
 
 }
@@ -46,17 +20,25 @@ UIPoint UIElement::getPosition() {
 	return UIPoint(uiToScreen(x), uiToScreen(y));
 }
 
-// Returns the element's position on the screen in pixels
-UIPoint UIElement::getScreenPosition() {
+// Returns the element's origin position on the screen in pixels (not offset by getBounds())
+UIPoint UIElement::getScreenOriginPosition() {
 	UIPoint pos = getPosition();
 	if(parent) {
-		UIPoint parentPos = parent->getPosition();
+		UIPoint parentPos = parent->getScreenPosition();
 		pos.x += parentPos.x;
 		pos.y += parentPos.y;
 	}
+
 	return pos;
 }
 
+// Returns the element's position on the screen in pixels (offset by getBounds())
+UIPoint UIElement::getScreenPosition() {
+	UIPoint pos = getScreenOriginPosition();
+	UIBounds bounds = getBounds();
+	return UIPoint(pos.x + bounds.x, pos.y + bounds.y);
+}
+
 std::vector<UIElement *> UIElement::getChildren() {
 	return children;
 }

src/kekengine/cpp/ui/uielements.cpp

@@ -145,7 +145,7 @@ void RectangleElement::draw(UIPoint screenPos, glm::mat4 projection) {
 	UIBounds offset = getBounds();
 
 	glUniformMatrix4fv(glGetUniformLocation(kekData.ui->rectangleShader->id, "projection"), 1, GL_FALSE, glm::value_ptr(projection));
-	glm::vec4 bounds = glm::vec4(offset.x + screenPos.x, offset.y + screenPos.y, uiToScreen(w), uiToScreen(h));
+	glm::vec4 bounds = glm::vec4(screenPos.x, screenPos.y, offset.w, offset.h);
 	glUniform4fv(glGetUniformLocation(kekData.ui->rectangleShader->id, "bounds"), 1, glm::value_ptr(bounds));
 	glUniform4fv(glGetUniformLocation(kekData.ui->rectangleShader->id, "rectColor"), 1, color.valuePointer());
 
@@ -156,6 +156,9 @@ void RectangleElement::draw(UIPoint screenPos, glm::mat4 projection) {
 ButtonElement::ButtonElement(UIValue x, UIValue y, UIValue w, UIValue h): RectangleElement(x, y, w, h) {
 	clickable = true;
 
+	color = Colors::CYAN;
+	hoverColor = Colors::CYAN.darker();
+
 	text = new TextElement(uiPw(0.5), uiPh(0.5));
 	text->origin = Origin::CENTER;
 	addChild(text);

src/kekengine/include/color.h

@@ -15,6 +15,14 @@ struct Color {
 		return &r;
 	}
 
+	constexpr Color darker(float factor = 0.7) const {
+		return Color(r * factor, g * factor, b * factor, a);
+	}
+
+	constexpr Color brighter(float factor = 0.7) const {
+		return Color(r / factor, g / factor, b / factor, a);
+	}
+
 };
 
 class Colors {

src/kekengine/include/ui.h

@@ -90,13 +90,31 @@ struct UIValue {
 
 	constexpr UIValue() = default;
 
-	constexpr UIValue &operator+=(const UIValue &rhs);
+	constexpr UIValue &operator+=(const UIValue &rhs) {
+		this->pixels += rhs.pixels;
+		this->parentWidth += rhs.parentWidth;
+		this->parentHeight += rhs.parentHeight;
+		this->screenWidth += rhs.screenWidth;
+		this->screenHeight += rhs.screenHeight;
+		return *this;
+	}
 
-	constexpr UIValue &operator-=(const UIValue &rhs);
+	constexpr UIValue &operator-=(const UIValue &rhs) {
+		this->pixels -= rhs.pixels;
+		this->parentWidth -= rhs.parentWidth;
+		this->parentHeight -= rhs.parentHeight;
+		this->screenWidth -= rhs.screenWidth;
+		this->screenHeight -= rhs.screenHeight;
+		return *this;
+	}
 
-	constexpr friend UIValue operator+(const UIValue &lhs, const UIValue &rhs);
+	constexpr friend UIValue operator+(const UIValue &lhs, const UIValue &rhs) {
+		return UIValue(lhs) += rhs;
+	}
 
-	constexpr friend UIValue operator-(const UIValue &lhs, const UIValue &rhs);
+	constexpr friend UIValue operator-(const UIValue &lhs, const UIValue &rhs) {
+		return UIValue(lhs) -= rhs;
+	}
 
 };
 
@@ -124,7 +142,10 @@ public:
 	// Returns the element's position relative to its parent in pixels
 	UIPoint getPosition();
 
-	// Returns the element's position on the screen in pixels
+	// Returns the element's origin position on the screen in pixels (not offset by getBounds())
+	UIPoint getScreenOriginPosition();
+
+	// Returns the element's position on the screen in pixels (offset by getBounds())
 	UIPoint getScreenPosition();
 
 	std::vector<UIElement *> getChildren();

src/kekgame/cpp/kekgame.cpp

@@ -131,6 +131,12 @@ int main(int argc, char **argv) {
 	button2->text->setText("Hi there!");
 	UI::addElement(button2);
 
+	ButtonElement *button3 = new ButtonElement(uiPx(10), uiPx(100), uiPx(200), uiPx(50));
+	button3->origin = Origin::BOTTOM_LEFT;
+	RectangleElement *rect = new RectangleElement(uiPx(0), uiPx(0), uiPw(0.5), uiPh(0.5));
+	button3->addChild(rect);
+	UI::addElement(button3);
+
 	if(Engine::start() != KEK_SUCCESS) return 1;
 	return 0;
 }