From 0f3888cfffa82900d25657e8c2c48ee861255762 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johan=20Hillerstr=C3=B6m?= <progr@mmer.nu>
Date: Sun, 15 Nov 2015 00:37:35 +0100
Subject: [PATCH] Implement the Hxy effect

---
 xmeffects.js | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/xmeffects.js b/xmeffects.js
index 0976b51..45b6319 100644
--- a/xmeffects.js
+++ b/xmeffects.js
@@ -191,6 +191,20 @@ function eff_t0_g(ch, data) {  // set global volume
   }
 }
 
+function eff_t0_h(ch, data) {  // global volume slide
+  if (data) {
+    // same as Axy but multiplied by 2
+    player.xm.global_volumeslide = (-(data & 0x0f) + (data >> 4)) * 2;
+  }
+}
+
+function eff_t1_h(ch) {  // global volume slide
+  if (player.xm.global_volumeslide !== undefined) {
+    player.xm.global_volume = Math.max(0, Math.min(player.max_global_volume,
+      player.xm.global_volume + player.xm.global_volumeslide));
+  }
+}
+
 function eff_t0_r(ch, data) {  // retrigger
   if (data & 0x0f) ch.retrig = (ch.retrig & 0xf0) + (data & 0x0f);
   if (data & 0xf0) ch.retrig = (ch.retrig & 0x0f) + (data & 0xf0);
@@ -244,7 +258,7 @@ player.effects_t0 = [  // effect functions on tick 0
   eff_t0_e,  // e
   eff_t0_f,  // f
   eff_t0_g,  // g
-  eff_unimplemented_t0,  // h
+  eff_t0_h,  // h
   eff_unimplemented_t0,  // i
   eff_unimplemented_t0,  // j
   eff_unimplemented_t0,  // k
@@ -283,7 +297,7 @@ player.effects_t1 = [  // effect functions on tick 1+
   eff_t1_e,  // e
   null,   // f
   null,  // g
-  eff_unimplemented,  // h
+  eff_t1_h,  // h
   eff_unimplemented,  // i
   eff_unimplemented,  // j
   eff_unimplemented,  // k