Merge pull request #1 from orsinium-labs/geometry

Geometry

Author: orsinium

_examples/snake/snake.go

@@ -39,7 +39,7 @@ func main() {
 
 // Update the snake direction based on the buttons pressed on the gamepad.
 func input() {
-	g := w4.Gamepads[0]
+	g := w4.Gamepad
 	if g.Up() {
 		snake.Up()
 	}

w4/api.go

@@ -1,19 +1,5 @@
 package w4
 
-type u8 = uint8
-
-// A point on the plane.
-type Point struct {
-	X u8
-	Y u8
-}
-
-// Size of a 2D shape.
-type Size struct {
-	Width  u8
-	Height u8
-}
-
 // Flags used with [Blit] and [BlitSub].
 type BlitFlags u8
 

w4/geom.go

@@ -0,0 +1,102 @@
+package w4
+
+type u8 = uint8
+
+// A point on the plane.
+type Point struct {
+	X u8
+	Y u8
+}
+
+// A point with equal x value and y set to 0.
+func (p Point) XAxis() Point {
+	p.Y = 0
+	return p
+}
+
+// A point with equal y value and x set to 0.
+func (p Point) YAxis() Point {
+	p.X = 0
+	return p
+}
+
+// The componentwise minimum of two Points.
+func (p Point) ComponentMin(other Point) Point {
+	if other.X < p.X {
+		p.X = other.X
+	}
+	if other.Y < p.Y {
+		p.Y = other.Y
+	}
+	return p
+}
+
+// The componentwise maximum of two Points.
+func (p Point) ComponentMax(other Point) Point {
+	if other.X > p.X {
+		p.X = other.X
+	}
+	if other.Y > p.Y {
+		p.Y = other.Y
+	}
+	return p
+}
+
+// Convert the Point to a Size with width equal to x and height equal to y.
+func (p Point) AsSize() Size {
+	return Size{Width: p.X, Height: p.Y}
+}
+
+// Add size width to the point x and size height to the point y.
+func (p Point) AddSize(s Size) Point {
+	p.X += s.Width
+	p.Y += s.Height
+	return p
+}
+
+// If the point is outside of the screen, wrap it around to fit on the screen.
+func (p Point) Wrap() Point {
+	p.X %= 160
+	p.Y %= 160
+	return p
+}
+
+// Size of a 2D shape.
+type Size struct {
+	Width  u8
+	Height u8
+}
+
+// Add two sizes together componentwise.
+func (s Size) AddSize(other Size) Size {
+	s.Width += other.Width
+	s.Height += other.Height
+	return s
+}
+
+// Convert Size to a Point with x set to width and y set to height.
+func (s Size) AsPoint() Point {
+	return Point{X: s.Width, Y: s.Height}
+}
+
+// The componentwise minimum of two Sizes.
+func (s Size) ComponentMin(other Size) Size {
+	if other.Width < s.Width {
+		s.Width = other.Width
+	}
+	if other.Height < s.Height {
+		s.Height = other.Height
+	}
+	return s
+}
+
+// The componentwise maximum of two Sizes.
+func (s Size) ComponentMax(other Size) Size {
+	if other.Width > s.Width {
+		s.Width = other.Width
+	}
+	if other.Height > s.Height {
+		s.Height = other.Height
+	}
+	return s
+}

w4/memory.go

@@ -122,6 +122,11 @@ func (drawColors) SetSecondary(c DrawColor) {
 
 type gamepad uint
 
+// The gamepad of the local player.
+//
+// The same as Gamepads[0].
+var Gamepad gamepad = 0x12
+
 // Check if X button is currently pressed on the gamepad.
 func (g gamepad) X() bool { return memory[g]&1 != 0 }
 
@@ -146,7 +151,7 @@ func (g gamepad) Any() bool { return memory[g] != 0 }
 // 4 gamepads, with each gamepad represented by a single byte.
 type gamepads []gamepad
 
-// And array of 4 gamepads.
+// An array of 4 gamepads.
 //
 //   - The first one is always available and is the local player.
 //   - The second one can be either a local hotseat player or a remote one.
@@ -155,6 +160,11 @@ type gamepads []gamepad
 // https://wasm4.org/docs/guides/user-input#gamepad
 var Gamepads = gamepads{0x12, 0x13, 0x14, 0x15}
 
+// Get a gamepad by index (from 0 to 3).
+func (gamepads) Get(idx u8) gamepad {
+	return Gamepads[idx]
+}
+
 type mouse struct{}
 
 // The mouse position and mouse buttons (left, right, and middle) state.