Fix calling toBitmap with an underlying hardware bitmap.

coil-core/src/androidInstrumentedTest/kotlin/coil3/ImageAndroidTest.kt

@@ -0,0 +1,29 @@
+package coil3
+
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import android.os.Build.VERSION.SDK_INT
+import coil3.core.test.R
+import coil3.test.utils.assumeTrue
+import coil3.test.utils.context
+import kotlin.test.assertEquals
+import kotlin.test.assertSame
+import org.junit.Test
+
+class ImageAndroidTest {
+
+    /** Regression test: https://github.com/coil-kt/coil/issues/2644 */
+    @Test
+    fun toBitmap_hardware() {
+        assumeTrue(SDK_INT >= 26)
+
+        // Decode a resource since we can't create a test hardware bitmap directly.
+        val options = BitmapFactory.Options().apply {
+            inPreferredConfig = Bitmap.Config.HARDWARE
+        }
+        val bitmap = BitmapFactory.decodeResource(context.resources, R.drawable.normal, options)
+
+        assertEquals(Bitmap.Config.HARDWARE, bitmap.config)
+        assertSame(bitmap, bitmap.asImage().toBitmap())
+    }
+}

coil-core/src/androidMain/kotlin/coil3/Image.android.kt

@@ -1,6 +1,7 @@
 package coil3
 
 import android.content.res.Resources
+import android.graphics.Bitmap
 import android.graphics.ColorFilter
 import android.graphics.PixelFormat
 import android.graphics.drawable.BitmapDrawable
@@ -12,6 +13,7 @@ import coil3.util.allocationByteCountCompat
 import coil3.util.height
 import coil3.util.width
 
+@Suppress("RemoveRedundantQualifierName")
 actual typealias Bitmap = android.graphics.Bitmap
 
 actual typealias Canvas = android.graphics.Canvas
@@ -25,12 +27,20 @@ actual fun Bitmap.asImage(shareable: Boolean): BitmapImage {
 actual fun Image.toBitmap(
     width: Int,
     height: Int,
-): Bitmap = toBitmap(width, height, android.graphics.Bitmap.Config.ARGB_8888)
+): Bitmap {
+    var bitmapConfig: Bitmap.Config? = null
+
+    if (this is BitmapImage) {
+        bitmapConfig = bitmap.config
+    }
+
+    return toBitmap(width, height, bitmapConfig ?: Bitmap.Config.ARGB_8888)
+}
 
 fun Image.toBitmap(
     width: Int,
     height: Int,
-    config: android.graphics.Bitmap.Config,
+    config: Bitmap.Config,
 ): Bitmap {
     if (this is BitmapImage &&
         bitmap.width == width &&

coil-core/src/nonAndroidMain/kotlin/coil3/Image.nonAndroid.kt

@@ -21,7 +21,23 @@ actual fun Bitmap.asImage(shareable: Boolean): BitmapImage {
 actual fun Image.toBitmap(
     width: Int,
     height: Int,
-): Bitmap = toBitmap(width, height, ColorType.N32, ColorAlphaType.PREMUL, null)
+): Bitmap {
+    val colorType: ColorType
+    val colorAlphaType: ColorAlphaType
+    val colorSpace: ColorSpace?
+
+    if (this is BitmapImage) {
+        colorType = bitmap.colorType
+        colorAlphaType = bitmap.imageInfo.colorAlphaType
+        colorSpace = bitmap.colorSpace
+    } else {
+        colorType = ColorType.N32
+        colorAlphaType = ColorAlphaType.PREMUL
+        colorSpace = null
+    }
+
+    return toBitmap(width, height, colorType, colorAlphaType, colorSpace)
+}
 
 fun Image.toBitmap(
     width: Int,