From 704a8dea0993f9903c524f035818a51b5c6793dd Mon Sep 17 00:00:00 2001
From: Francesco Abbate <francesco.bbt@gmail.com>
Date: Wed, 9 Jun 2021 23:37:03 +0200
Subject: [PATCH] Group mouse move events from C API function

Groups together consecutive mouse move events like done in core.step()
lua function but on the C side.

It does not introduce any meaningful speedup but it theory is more efficient and
simplifies the Lua code.

The simplification of the Lua code alone is enough to justify this change?
---
 data/core/init.lua | 14 +++-----------
 src/api/system.c   |  8 ++++++++
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/data/core/init.lua b/data/core/init.lua
index cc4b46d8..95eb7973 100644
--- a/data/core/init.lua
+++ b/data/core/init.lua
@@ -948,26 +948,18 @@ end
 function core.step()
   -- handle events
   local did_keymap = false
-  local mouse_moved = false
-  local mouse = { x = 0, y = 0, dx = 0, dy = 0 }
-
 
   for type, a,b,c,d in system.poll_event do
-    if type == "mousemoved" then
-      mouse_moved = true
-      mouse.x, mouse.y = a, b
-      mouse.dx, mouse.dy = mouse.dx + c, mouse.dy + d
-    elseif type == "textinput" and did_keymap then
+    if type == "textinput" and did_keymap then
       did_keymap = false
+    elseif type == "mousemoved" then
+      core.try(core.on_event, type, a, b, c, d)
     else
       local _, res = core.try(core.on_event, type, a, b, c, d)
       did_keymap = res or did_keymap
     end
     core.redraw = true
   end
-  if mouse_moved then
-    core.try(core.on_event, "mousemoved", mouse.x, mouse.y, mouse.dx, mouse.dy)
-  end
 
   local width, height = renderer.get_size()
 
diff --git a/src/api/system.c b/src/api/system.c
index bbe0801b..d00a9e47 100644
--- a/src/api/system.c
+++ b/src/api/system.c
@@ -201,6 +201,14 @@ top:
       return 4;
 
     case SDL_MOUSEMOTION:
+      SDL_PumpEvents();
+      SDL_Event event_plus;
+      while (SDL_PeepEvents(&event_plus, 1, SDL_GETEVENT, SDL_MOUSEMOTION, SDL_MOUSEMOTION) > 0) {
+        e.motion.x = event_plus.motion.x;
+        e.motion.y = event_plus.motion.y;
+        e.motion.xrel += event_plus.motion.xrel;
+        e.motion.yrel += event_plus.motion.yrel;
+      }
       lua_pushstring(L, "mousemoved");
       lua_pushnumber(L, e.motion.x);
       lua_pushnumber(L, e.motion.y);