From e5639f8622045046adef539a3e8f29eb2ff00522 Mon Sep 17 00:00:00 2001
From: Zac Brown <git@zacbrown.org>
Date: Sat, 7 Dec 2019 22:16:44 -0800
Subject: [PATCH] Day 8, part 2 complete.

---
 cmd/day8/main.go                | 49 ++++++++++++++++++++++++++++++---
 cmd/day8/simple_image_data2.txt |  1 +
 2 files changed, 46 insertions(+), 4 deletions(-)
 create mode 100644 cmd/day8/simple_image_data2.txt

diff --git a/cmd/day8/main.go b/cmd/day8/main.go
index 8da01be..283e2aa 100644
--- a/cmd/day8/main.go
+++ b/cmd/day8/main.go
@@ -28,10 +28,12 @@ func loadImageData(filename string) string {
 }
 
 const (
-	imageWidth      = 25
-	imageHeight     = 6
-	testImageWidth  = 3
-	testImageHeight = 2
+	imageWidth       = 25
+	imageHeight      = 6
+	testImageWidth   = 3
+	testImageHeight  = 2
+	testImage2Width  = 2
+	testImage2Height = 2
 )
 
 type Layer [imageHeight][imageWidth]int
@@ -94,6 +96,41 @@ func findImageChecksum(layer Layer) int {
 	return ones * twos
 }
 
+const (
+	BLACK       = 0
+	WHITE       = 1
+	TRANSPARENT = 2
+)
+
+func renderFinalImage(layers []Layer) Layer {
+	final := layers[0]
+
+	for _, l := range layers[1:] {
+		for ii := 0; ii < len(l); ii++ {
+			for jj := 0; jj < len(l[ii]); jj++ {
+				if final[ii][jj] == TRANSPARENT {
+					final[ii][jj] = l[ii][jj]
+				}
+			}
+		}
+	}
+
+	return final
+}
+
+func displayRenderedImage(layer Layer) {
+	for ii := 0; ii < len(layer); ii++ {
+		for jj := 0; jj < len(layer[ii]); jj++ {
+			if layer[ii][jj] == BLACK {
+				print("@@@")
+			} else {
+				print("   ")
+			}
+		}
+		println()
+	}
+}
+
 func main() {
 	imageData := loadImageData(os.Args[1])
 	println("imageData: ", imageData)
@@ -103,4 +140,8 @@ func main() {
 
 	fmt.Printf("lowestZeroLayer: %v\n", lowestZeroLayer)
 	fmt.Printf("[Part 1] Answer: %v\n", findImageChecksum(lowestZeroLayer))
+	println()
+	println("[Part 2] Answer:")
+	renderedImage := renderFinalImage(layers)
+	displayRenderedImage(renderedImage)
 }
diff --git a/cmd/day8/simple_image_data2.txt b/cmd/day8/simple_image_data2.txt
new file mode 100644
index 0000000..adee405
--- /dev/null
+++ b/cmd/day8/simple_image_data2.txt
@@ -0,0 +1 @@
+0222112222120000
\ No newline at end of file
-- 
2.45.2