Add support for triangle shape

Author: Patxi Bocos

.gitignore

@@ -59,3 +59,6 @@ captures/
 jarRepositories.xml
 androidTestResultsUserPreferences.xml
 migrations.xml
+
+# macOS
+.DS_Store

konfetti/compose/src/main/java/nl/dionsegijn/konfetti/compose/DrawShapes.kt

@@ -8,6 +8,7 @@ import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.Path
 import androidx.compose.ui.graphics.drawscope.DrawScope
 import androidx.compose.ui.graphics.drawscope.drawIntoCanvas
 import androidx.compose.ui.graphics.nativeCanvas
@@ -19,6 +20,7 @@ import nl.dionsegijn.konfetti.core.models.Shape.DrawableShape
 import nl.dionsegijn.konfetti.core.models.Shape.Rectangle
 import nl.dionsegijn.konfetti.core.models.Shape.Square
 import nl.dionsegijn.konfetti.xml.image.ImageStore
+import kotlin.math.sqrt
 
 /**
  * Draw a shape to `compose canvas`. Implementations are expected to draw within a square of size
@@ -84,5 +86,19 @@ fun Shape.draw(
                 }
             }
         }
+        Shape.Triangle -> {
+            val triangleWidth = particle.width
+            val triangleHeight = triangleWidth * sqrt(3.0) / 2
+            val trianglePath =
+                Path().apply {
+                    moveTo(particle.x + particle.width / 2, particle.y)
+                    lineTo(particle.x + triangleWidth, particle.y + triangleHeight.toFloat())
+                    lineTo(particle.x, particle.y + triangleHeight.toFloat())
+                }
+            drawScope.drawPath(
+                color = Color(particle.color),
+                path = trianglePath,
+            )
+        }
     }
 }

konfetti/core/src/main/java/nl/dionsegijn/konfetti/core/models/Shape.kt

@@ -8,6 +8,8 @@ sealed interface Shape {
 
     object Square : Shape
 
+    object Triangle : Shape
+
     class Rectangle(
         /** The ratio of height to width. Must be within range [0, 1] */
         val heightRatio: Float,

konfetti/xml/src/main/java/nl/dionsegijn/konfetti/xml/DrawShapes.kt

@@ -4,6 +4,7 @@ import android.graphics.BlendMode
 import android.graphics.BlendModeColorFilter
 import android.graphics.Canvas
 import android.graphics.Paint
+import android.graphics.Path
 import android.graphics.PorterDuff
 import android.graphics.RectF
 import android.os.Build
@@ -15,6 +16,7 @@ import nl.dionsegijn.konfetti.core.models.Shape.DrawableShape
 import nl.dionsegijn.konfetti.core.models.Shape.Rectangle
 import nl.dionsegijn.konfetti.core.models.Shape.Square
 import nl.dionsegijn.konfetti.xml.image.ImageStore
+import kotlin.math.sqrt
 
 /**
  * Draw a shape to `canvas`. Implementations are expected to draw within a square of size
@@ -61,5 +63,15 @@ fun Shape.draw(
                 drawable.draw(canvas)
             }
         }
+        Shape.Triangle -> {
+            val triangleHeight = size * sqrt(3.0) / 2
+            val trianglePath =
+                Path().apply {
+                    moveTo(size / 2, 0f)
+                    lineTo(size, triangleHeight.toFloat())
+                    lineTo(0f, triangleHeight.toFloat())
+                }
+            canvas.drawPath(trianglePath, paint)
+        }
     }
 }