From 3d600c69558b4b3e3f05b860531942f1ea2cd1c1 Mon Sep 17 00:00:00 2001
From: Simon Robertshaw <simon@hardwired.org.uk>
Date: Wed, 1 Jun 2011 12:16:33 +0100
Subject: [PATCH] Add gravity field manipulation to Lua api, move gravity
 processing to after the particle update (Means a delay of 1 frame, but we get
 the ability to manipulate the field with Lua)

---
 build/test.lua        |  6 +++-
 includes/luaconsole.h |  4 ++-
 src/luaconsole.c      | 71 ++++++++++++++++++++++++++++++++++++++++---
 src/main.c            | 14 ++++-----
 4 files changed, 82 insertions(+), 13 deletions(-)

diff --git a/build/test.lua b/build/test.lua
index fbb062fbd..a41bdd772 100644
--- a/build/test.lua
+++ b/build/test.lua
@@ -10,5 +10,9 @@ function do_step()
 	end
 	tpt.drawtext(numberthing, 50, "Oh my god, this is amazing", 255, 255, 255, 255)
 	tpt.drawtext(mousex, mousey, "Oh my god, this is amazing", 255, 255, 255, 255)
-	return true
+	tpt.reset_velocity(10, 10, 20, 20)
+	tpt.reset_gravity_field(10, 10, 20, 20)
+	tpt.set_pressure(10, 10, 20, 20)
+	tpt.set_gravity(75, 45, 1, 1, 8)
+	return false
 end
diff --git a/includes/luaconsole.h b/includes/luaconsole.h
index 187bf01b5..c64661903 100644
--- a/includes/luaconsole.h
+++ b/includes/luaconsole.h
@@ -21,7 +21,9 @@ int luatpt_setpause(lua_State* l);
 int luatpt_togglepause(lua_State* l);
 int luatpt_setconsole(lua_State* l);
 int luatpt_log(lua_State* l);
-int luatpt_reset_pressure(lua_State* l);
+int luatpt_set_pressure(lua_State* l);
+int luatpt_set_gravity(lua_State* l);
+int luatpt_reset_gravity_field(lua_State* l);
 int luatpt_reset_velocity(lua_State* l);
 int luatpt_reset_spark(lua_State* l);
 int luatpt_set_property(lua_State* l);
diff --git a/src/luaconsole.c b/src/luaconsole.c
index 9e55d760e..0f1b96e1e 100644
--- a/src/luaconsole.c
+++ b/src/luaconsole.c
@@ -14,7 +14,9 @@ void luacon_open(){
 		{"toggle_pause", &luatpt_togglepause},
 		{"set_console", &luatpt_setconsole},
 		{"log", &luatpt_log},
-		{"reset_pressure", &luatpt_reset_pressure},
+		{"set_pressure", &luatpt_set_pressure},
+		{"set_gravity", &luatpt_set_gravity},
+		{"reset_gravity_field", &luatpt_reset_gravity_field},
 		{"reset_velocity", &luatpt_reset_velocity},
 		{"reset_spark", &luatpt_reset_spark},
 		{"set_property", &luatpt_set_property},
@@ -35,6 +37,7 @@ void luacon_open(){
 	luaL_openlib(l, "tpt", tptluaapi, 0);
 }
 int luacon_step(int mx, int my, int mb, int mbq, char key){
+	int tempret = 0;
 	if(step_function && step_function[0]){
 		//Set mouse globals
 		lua_pushinteger(l, mbq);
@@ -46,8 +49,12 @@ int luacon_step(int mx, int my, int mb, int mbq, char key){
 		lua_setfield(l, LUA_GLOBALSINDEX, "mouseb");
 		lua_setfield(l, LUA_GLOBALSINDEX, "mousebq");
 		lua_getfield(l, LUA_GLOBALSINDEX, step_function);
-		lua_call(l, 0, 0);
-		return lua_toboolean(l, -1);
+		lua_call(l, 0, 1);
+		if(lua_isboolean(l, -1)){
+			tempret = lua_toboolean(l, -1);
+			lua_pop(l, 1);
+			return tempret;
+		}
 	}
 	return 0;
 }
@@ -171,7 +178,7 @@ int luatpt_log(lua_State* l)
 	return 0;
 }
 
-int luatpt_reset_pressure(lua_State* l)
+int luatpt_set_pressure(lua_State* l)
 {
 	int nx, ny;
 	int x1, y1, width, height;
@@ -202,6 +209,62 @@ int luatpt_reset_pressure(lua_State* l)
 	return 0;
 }
 
+int luatpt_set_gravity(lua_State* l)
+{
+	int nx, ny;
+	int x1, y1, width, height;
+	float value;
+	x1 = abs(luaL_optint(l, 1, 0));
+	y1 = abs(luaL_optint(l, 2, 0));
+	width = abs(luaL_optint(l, 3, XRES/CELL));
+	height = abs(luaL_optint(l, 4, YRES/CELL));
+	value = (float)luaL_optint(l, 5, 0.0f);
+	if(value > 256.0f)
+		value = 256.0f;
+	else if(value < -256.0f)
+		value = -256.0f;	
+	
+	if(x1 > (XRES/CELL)-1)
+		x1 = (XRES/CELL)-1;
+	if(y1 > (YRES/CELL)-1) 
+		y1 = (YRES/CELL)-1;	
+	if(x1+width > (XRES/CELL)-1)
+		width = (XRES/CELL)-x1;
+	if(y1+height > (YRES/CELL)-1)
+		height = (YRES/CELL)-y1;
+	for (nx = x1; nx<x1+width; nx++)
+		for (ny = y1; ny<y1+height; ny++)
+		{
+			gravmap[ny][nx] = value;
+		}
+	return 0;
+}
+
+int luatpt_reset_gravity_field(lua_State* l)
+{
+	int nx, ny;
+	int x1, y1, width, height;
+	x1 = abs(luaL_optint(l, 1, 0));
+	y1 = abs(luaL_optint(l, 2, 0));
+	width = abs(luaL_optint(l, 3, XRES/CELL));
+	height = abs(luaL_optint(l, 4, YRES/CELL));
+	if(x1 > (XRES/CELL)-1)
+		x1 = (XRES/CELL)-1;
+	if(y1 > (YRES/CELL)-1) 
+		y1 = (YRES/CELL)-1;	
+	if(x1+width > (XRES/CELL)-1)
+		width = (XRES/CELL)-x1;
+	if(y1+height > (YRES/CELL)-1)
+		height = (YRES/CELL)-y1;
+	for (nx = x1; nx<x1+width; nx++)
+		for (ny = y1; ny<y1+height; ny++)
+		{
+			gravx[ny][nx] = 0;
+			gravy[ny][nx] = 0;
+		}
+	return 0;
+}
+
 int luatpt_reset_velocity(lua_State* l)
 {
 	int nx, ny;
diff --git a/src/main.c b/src/main.c
index bbaee6887..8b3d96ab5 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1775,7 +1775,13 @@ int main(int argc, char *argv[])
 			bsy = 1180;
 		if (bsy<0)
 			bsy = 0;
-
+		
+		if(ngrav_enable)
+			draw_grav(vid_buf);
+		draw_walls(vid_buf);
+		update_particles(vid_buf); //update everything
+		draw_parts(vid_buf); //draw particles
+		
 		if(ngrav_enable){
 			pthread_mutex_lock(&gravmutex);
 			result = grav_ready;
@@ -1794,12 +1800,6 @@ int main(int argc, char *argv[])
 
 		if (!sys_pause||framerender) //Only update if not paused
 			memset(gravmap, 0, sizeof(gravmap)); //Clear the old gravmap
-		
-		if(ngrav_enable)
-			draw_grav(vid_buf);
-		draw_walls(vid_buf);
-		update_particles(vid_buf); //update everything
-		draw_parts(vid_buf); //draw particles
 
 		if (cmode==CM_PERS)
 		{