sprites!!!!!!

1 files changed, 119 insertions, 0 deletions

diff --git a/tests/controller_test.go b/tests/controller_test.go
new file mode 100644
index 0000000..026e68a
--- /dev/null
+++ b/tests/controller_test.go
@@ -0,0 +1,119 @@
+package tests
+
+import (
+	"testing"
+
+	"crecher.net/gones/v2/cart"
+	"crecher.net/gones/v2/nes"
+)
+
+func newTestConsole(t *testing.T) *nes.Console {
+	t.Helper()
+	c, err := cart.Load("testdata/nestest.nes")
+	if err != nil {
+		t.Fatal(err)
+	}
+	return nes.New(c)
+}
+
+func strobe(n *nes.Console) {
+	n.Write(0x4016, 1)
+	n.Write(0x4016, 0)
+}
+
+func readBits(n *nes.Console, addr uint16, count int) []uint8 {
+	bits := make([]uint8, count)
+	for i := range bits {
+		bits[i] = n.Read(addr) & 1
+	}
+	return bits
+}
+
+func equalBits(a, b []uint8) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := range a {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func TestControllerReadsButtonsInOrder(t *testing.T) {
+	n := newTestConsole(t)
+	n.SetButtons(0, nes.ButtonA|nes.ButtonStart|nes.ButtonRight)
+	strobe(n)
+
+	//				+---------------------- A
+	//				|  +------------------- B
+	//				|  |  +---------------- Select
+	//				|  |  |  +------------- Start
+	//				|  |  |  |  +---------- Up
+	//				|  |  |  |  |  +------- Down
+	//				|  |  |  |  |  |  +---- Left
+	//				|  |  |  |  |  |  |  +- Right
+	//				|  |  |  |  |  |  |  |
+	want := []uint8{1, 0, 0, 1, 0, 0, 0, 1}
+	if got := readBits(n, 0x4016, 8); !equalBits(got, want) {
+		t.Errorf("bits = %v, want %v", got, want)
+	}
+}
+
+func TestControllerReturnsOneAfterEightReads(t *testing.T) {
+	n := newTestConsole(t)
+	strobe(n)
+	readBits(n, 0x4016, 8)
+	if got := readBits(n, 0x4016, 3); !equalBits(got, []uint8{1, 1, 1}) {
+		t.Errorf("bits after 8 reads = %v, want [1 1 1]", got)
+	}
+}
+
+func TestControllerStrobeHighKeepsReturningA(t *testing.T) {
+	n := newTestConsole(t)
+	n.SetButtons(0, nes.ButtonA)
+	n.Write(0x4016, 1)
+	if got := readBits(n, 0x4016, 3); !equalBits(got, []uint8{1, 1, 1}) {
+		t.Errorf("bits = %v, want [1 1 1]", got)
+	}
+
+	n.SetButtons(0, nes.ButtonB)
+	if got := readBits(n, 0x4016, 2); !equalBits(got, []uint8{0, 0}) {
+		t.Errorf("bits after releasing A = %v, want [0 0]", got)
+	}
+}
+
+func TestControllerLatchesOnStrobe(t *testing.T) {
+	n := newTestConsole(t)
+	n.SetButtons(0, nes.ButtonA)
+	strobe(n)
+	n.SetButtons(0, 0) // released after the latch, the readout should not change
+
+	want := []uint8{1, 0, 0, 0, 0, 0, 0, 0}
+	if got := readBits(n, 0x4016, 8); !equalBits(got, want) {
+		t.Errorf("bits = %v, want %v", got, want)
+	}
+}
+
+func TestControllerPortsAreIndependentWithSharedStrobe(t *testing.T) {
+	n := newTestConsole(t)
+	n.SetButtons(0, nes.ButtonA)
+	n.SetButtons(1, nes.ButtonSelect)
+	strobe(n)
+
+	if got := readBits(n, 0x4016, 3); !equalBits(got, []uint8{1, 0, 0}) {
+		t.Errorf("port 1 bits = %v, want [1 0 0]", got)
+	}
+	if got := readBits(n, 0x4017, 3); !equalBits(got, []uint8{0, 0, 1}) {
+		t.Errorf("port 2 bits = %v, want [0 0 1]", got)
+	}
+}
+
+func TestControllerReadHasOpenBusBit6(t *testing.T) {
+	n := newTestConsole(t)
+	strobe(n)
+	if got := n.Read(0x4016); got != 0x40 {
+		t.Errorf("$4016 with nothing pressed = %#02x, want 0x40", got)
+	}
+}