move examples into subfolder, added wasm4 skip_ahead

examples/microw8/random.cwa

@@ -0,0 +1,35 @@
+import "env.memory" memory(4);
+
+global mut randomState: i64 = 37i64;
+
+fn random() -> i32 {
+    (random64() >> 32i64) as i32
+}
+
+fn random64() -> i64 {
+    let state: i64;
+    randomState = (state := (
+                          state := randomState ^ (randomState >> 12i64)
+                      ) ^ (state << 25i64)
+                  ) ^ (state >> 27i64);
+    randomState * 2685821657736338717i64
+}
+
+fn randomf() -> f32 {
+    f32.reinterpret_i32(1065353216 | (random() >> 9)) - 1 as f32
+}
+
+fn seed(s: i32) {
+    randomState = (s as i64 << 32i64) ^ ((63 - s) as i64);
+    randomState = random64();
+    randomState = random64();
+}
+
+export fn tic(time: i32) {
+    let i: i32;
+    loop pixels {
+        seed(i + (time / 100) * 320);
+        i?120 = (randomf() * 256 as f32 + time as f32 / 10 as f32) as i32;
+        branch_if (i := i + 1) < 320*256: pixels
+    }
+}