fix: anim tests and mfp bug

pkg/anim/anim_test.go

@@ -0,0 +1,33 @@
+package anim
+
+import (
+	"testing"
+	"time"
+
+	"github.com/cfoust/cy/pkg/geom"
+	"github.com/cfoust/cy/pkg/geom/image"
+)
+
+// Subject all animations to a few simple smoke tests.
+func TestAnims(t *testing.T) {
+	for name, anim := range Animations {
+		t.Logf("testing anim %s", name)
+
+		// The most common point of failure for animations is failing
+		// to do adequate bounds checks. This renders every animation
+		// at a few different sizes to ensure that doesn't happen.
+		for _, size := range []geom.Size{
+			geom.Size{},
+			geom.Size{
+				R: 5,
+				C: 5,
+			},
+			geom.DEFAULT_SIZE,
+		} {
+			instance := anim()
+			instance.Init(image.New(size))
+			instance.Update(0)
+			instance.Update(time.Second)
+		}
+	}
+}

pkg/anim/musicforprogramming/module.go

@@ -376,14 +376,16 @@ func (r *MFP) drawVisualizer(delta time.Duration) {
 }
 
 func (r *MFP) Update(delta time.Duration) image.Image {
+	size := r.out.Size()
+
 	r.drawBackground(delta)
 	image.Copy(geom.Vec2{}, r.out, r.bg)
 
 	colOffset := 1
 	rowOffset := 1
 
-	for row := 0; row < r.out.Size().R; row++ {
-		for col := 0; col < geom.Min(r.out.Size().C-1, PANEL_WIDTH+colOffset); col++ {
+	for row := 0; row < size.R; row++ {
+		for col := 0; col < geom.Min(size.C-1, PANEL_WIDTH+colOffset); col++ {
 			r.out[row][col].Char = ' '
 		}
 	}
@@ -404,6 +406,11 @@ func (r *MFP) Update(delta time.Duration) image.Image {
 	for col := 0; col < PANEL_WIDTH; col++ {
 		cellRow := visualRow + VISUAL_HEIGHT
 		cellCol := col + colOffset
+
+		if cellRow >= size.R || cellCol >= size.C {
+			continue
+		}
+
 		r.out[cellRow][cellCol].Char = TRACK_TITLE[(col+titleIndex)%len(TRACK_TITLE)]
 		r.out[cellRow][cellCol].FG = emu.ANSIColor(8)
 	}