From 721ac5f4d84e46e237a3a13b4eae22ea4f0e8b2c Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Mon, 20 Feb 2012 23:54:33 -0500
Subject: [PATCH] Fixed bug 1423 - Finger touch events don't report pressure

Philip Taylor 2012-02-19 08:34:52 PST

SDL_touch.c never actually uses the 'pressurein' arguments to
SDL_SendFingerDown/SDL_SendTouchMotion, so it doesn't report the real pressure.
Also it uses touch->pressureres which is never initialised. Also it fails to
initialise some fields of event.tfinger for certain events, so applications
might try to use bogus data.

The attached patch seems to be enough to produce generally sensible output on
Android.
---
 src/events/SDL_touch.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/events/SDL_touch.c b/src/events/SDL_touch.c
index fec2d548f..2e9cd10a7 100755
--- a/src/events/SDL_touch.c
+++ b/src/events/SDL_touch.c
@@ -141,6 +141,7 @@ SDL_AddTouch(const SDL_Touch * touch, char *name)
     
     SDL_touchPads[index]->xres = (1<<(16-1));
     SDL_touchPads[index]->yres = (1<<(16-1));
+    SDL_touchPads[index]->pressureres = (1<<(16-1));
     //Do I want this here? Probably
     SDL_GestureAddTouch(SDL_touchPads[index]);
 
@@ -329,7 +330,7 @@ SDL_SendFingerDown(SDL_TouchID id, SDL_FingerID fingerid, SDL_bool down,
     //scale to Integer coordinates
     x = (Uint16)((xin+touch->x_min)*(touch->xres)/(touch->native_xres));
     y = (Uint16)((yin+touch->y_min)*(touch->yres)/(touch->native_yres));
-    pressure = (Uint16)((yin+touch->pressure_min)*(touch->pressureres)/(touch->native_pressureres));
+    pressure = (Uint16)((pressurein+touch->pressure_min)*(touch->pressureres)/(touch->native_pressureres));
     
     finger = SDL_GetFinger(touch,fingerid);
     if(down) {
@@ -357,6 +358,8 @@ SDL_SendFingerDown(SDL_TouchID id, SDL_FingerID fingerid, SDL_bool down,
             event.tfinger.touchId = id;
             event.tfinger.x = x;
             event.tfinger.y = y;
+            event.tfinger.dx = 0;
+            event.tfinger.dy = 0;
             event.tfinger.pressure = pressure;
             event.tfinger.state = touch->buttonstate;
             event.tfinger.windowID = touch->focus ? touch->focus->id : 0;
@@ -384,6 +387,7 @@ SDL_SendFingerDown(SDL_TouchID id, SDL_FingerID fingerid, SDL_bool down,
             event.tfinger.y = finger->y;
             event.tfinger.dx = 0;
             event.tfinger.dy = 0;
+            event.tfinger.pressure = pressure;
 
             if(SDL_DelFinger(touch,fingerid) < 0) return 0;
             posted = (SDL_PushEvent(&event) > 0);
@@ -412,7 +416,7 @@ SDL_SendTouchMotion(SDL_TouchID id, SDL_FingerID fingerid, int relative,
     //scale to Integer coordinates
     x = (Uint16)((xin+touch->x_min)*(touch->xres)/(touch->native_xres));
     y = (Uint16)((yin+touch->y_min)*(touch->yres)/(touch->native_yres));
-    pressure = (Uint16)((yin+touch->pressure_min)*(touch->pressureres)/(touch->native_pressureres));
+    pressure = (Uint16)((pressurein+touch->pressure_min)*(touch->pressureres)/(touch->native_pressureres));
     if(touch->flush_motion) {
         return 0;
     }