From 1be79e581d31f1c40051f916128ecbce64f80022 Mon Sep 17 00:00:00 2001
From: jacksonmj <mj-pt@jacksonmj.co.uk>
Date: Tue, 12 Jul 2011 16:35:55 +0800
Subject: [PATCH] Line snapping (hold down Alt when drawing a line)

Specific element select changed to Ctrl+Alt
---
 README          |  2 +-
 src/interface.c | 24 ++++++++++++------------
 src/main.c      | 36 +++++++++++++++++++++++++-----------
 src/powder.c    |  6 +++---
 4 files changed, 41 insertions(+), 27 deletions(-)

diff --git a/README b/README
index c9174be44..27a6f7ab6 100644
--- a/README
+++ b/README
@@ -70,7 +70,7 @@ Ctrl + Mouse scroll 	Change vertical brush size
 Shift + Mouse scroll 	Change horizontal brush size
 Shift + Ctrl + R 	Horizontal mirror for selected area
 Ctrl + R 		Rotate selected area counterclockwise
-Shift + Left Alt	Select subject for Specific Element erase
+Ctrl + Left Alt	Select subject for Specific Element erase
 Ctrl + = 		Reset Electricity 
 
 
diff --git a/src/interface.c b/src/interface.c
index 64a899163..3f14e7f7c 100644
--- a/src/interface.c
+++ b/src/interface.c
@@ -1923,7 +1923,7 @@ void menu_ui_v3(pixel *vid_buf, int i, int *sl, int *sr, int *dae, int b, int bq
 					drawrect(vid_buf, x+30, y-1, 29, 17, 255, 55, 55, 255);
 					h = n;
 				}
-				if (!bq && mx>=x+32 && mx<x+58 && my>=y && my< y+15&&(sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_SHIFT)))
+				if (!bq && mx>=x+32 && mx<x+58 && my>=y && my< y+15&&(sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_CTRL)))
 				{
 					drawrect(vid_buf, x+30, y-1, 29, 17, 0, 255, 255, 255);
 					h = n;
@@ -1960,7 +1960,7 @@ void menu_ui_v3(pixel *vid_buf, int i, int *sl, int *sr, int *dae, int b, int bq
 					drawrect(vid_buf, x+30, y-1, 29, 17, 255, 55, 55, 255);
 					h = n;
 				}
-				if (!bq && mx>=x+32 && mx<x+58 && my>=y && my< y+15&&(sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_SHIFT)))
+				if (!bq && mx>=x+32 && mx<x+58 && my>=y && my< y+15&&(sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_CTRL)))
 				{
 					drawrect(vid_buf, x+30, y-1, 29, 17, 0, 255, 255, 255);
 					h = n;
@@ -1994,7 +1994,7 @@ void menu_ui_v3(pixel *vid_buf, int i, int *sl, int *sr, int *dae, int b, int bq
 					drawrect(vid_buf, x+30, y-1, 29, 17, 255, 55, 55, 255);
 					h = n;
 				}
-				if (!bq && mx>=x+32 && mx<x+58 && my>=y && my< y+15&&(sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_SHIFT)))
+				if (!bq && mx>=x+32 && mx<x+58 && my>=y && my< y+15&&(sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_CTRL)))
 				{
 					drawrect(vid_buf, x+30, y-1, 29, 17, 0, 255, 255, 255);
 					h = n;
@@ -2065,7 +2065,7 @@ void menu_ui_v3(pixel *vid_buf, int i, int *sl, int *sr, int *dae, int b, int bq
 					drawrect(vid_buf, x+30-xoff, y-1, 29, 17, 255, 55, 55, 255);
 					h = n;
 				}
-				if (!bq && mx>=x+32-xoff && mx<x+58-xoff && my>=y && my< y+15&&(sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_SHIFT)))
+				if (!bq && mx>=x+32-xoff && mx<x+58-xoff && my>=y && my< y+15&&(sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_CTRL)))
 				{
 					drawrect(vid_buf, x+30-xoff, y-1, 29, 17, 0, 255, 255, 255);
 					h = n;
@@ -2086,7 +2086,7 @@ void menu_ui_v3(pixel *vid_buf, int i, int *sl, int *sr, int *dae, int b, int bq
 		}
 	}
 	if (!bq && mx>=((XRES+BARSIZE)-16) ) //highlight menu section
-		if (sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_SHIFT))
+		if (sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_CTRL))
 			if (i>=0&&i<SC_TOTAL)
 				SEC = i;
 
@@ -2110,7 +2110,7 @@ void menu_ui_v3(pixel *vid_buf, int i, int *sl, int *sr, int *dae, int b, int bq
 	//h has the value of the element it is over, and -1 if not over an element
 	if (b==1&&h==-1)
 	{
-		if (sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_SHIFT) && SEC>=0)
+		if (sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_CTRL) && SEC>=0)
 		{
 			SLALT = -1;
 			SEC2 = SEC;
@@ -2118,7 +2118,7 @@ void menu_ui_v3(pixel *vid_buf, int i, int *sl, int *sr, int *dae, int b, int bq
 	}
 	if (b==1&&h!=-1)
 	{
-		if (sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_SHIFT))
+		if (sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_CTRL))
 		{
 			SLALT = h;
 			SEC2 = -1;
@@ -2130,7 +2130,7 @@ void menu_ui_v3(pixel *vid_buf, int i, int *sl, int *sr, int *dae, int b, int bq
 	}
 	if (b==4&&h==-1)
 	{
-		if (sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_SHIFT) && SEC>=0)
+		if (sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_CTRL) && SEC>=0)
 		{
 			SLALT = -1;
 			SEC2 = SEC;
@@ -2138,7 +2138,7 @@ void menu_ui_v3(pixel *vid_buf, int i, int *sl, int *sr, int *dae, int b, int bq
 	}
 	if (b==4&&h!=-1)
 	{
-		if (sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_SHIFT))
+		if (sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_CTRL))
 		{
 			SLALT = h;
 			SEC2 = -1;
@@ -5010,7 +5010,7 @@ unsigned int decorations_ui(pixel *vid_buf,int *bsx,int *bsy, unsigned int saved
 			}
 			else //first click
 			{
-				if ((sdl_mod & (KMOD_LSHIFT|KMOD_RSHIFT)) && !(sdl_mod & (KMOD_LCTRL|KMOD_RCTRL|KMOD_LALT)))
+				if ((sdl_mod & (KMOD_SHIFT)) && !(sdl_mod & (KMOD_CTRL)))
 				{
 					lx = mx;
 					ly = my;
@@ -5018,7 +5018,7 @@ unsigned int decorations_ui(pixel *vid_buf,int *bsx,int *bsy, unsigned int saved
 					lm = 1;//line
 				}
 				//start box tool
-				else if ((sdl_mod & (KMOD_LCTRL|KMOD_RCTRL)) && !(sdl_mod & (KMOD_LSHIFT|KMOD_RSHIFT)))
+				else if ((sdl_mod & (KMOD_CTRL)) && !(sdl_mod & (KMOD_SHIFT|KMOD_ALT)))
 				{
 					lx = mx;
 					ly = my;
@@ -5026,7 +5026,7 @@ unsigned int decorations_ui(pixel *vid_buf,int *bsx,int *bsy, unsigned int saved
 					lm = 2;//box
 				}
 				//sample tool
-				else if (((sdl_mod & (KMOD_LALT|KMOD_RALT)) && !(sdl_mod & (KMOD_SHIFT))) || b==SDL_BUTTON_MIDDLE)
+				else if (((sdl_mod & (KMOD_ALT)) && !(sdl_mod & (KMOD_SHIFT|KMOD_CTRL))) || b==SDL_BUTTON_MIDDLE)
 				{
 					if (my>=0 && my<YRES && mx>=0 && mx<XRES)
 					{
diff --git a/src/main.c b/src/main.c
index e8ece5c5b..9d6846509 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1561,7 +1561,7 @@ int main(int argc, char *argv[])
 	int vs = 0;
 #endif
 	int wavelength_gfx = 0;
-	int x, y, b = 0, sl=1, sr=0, su=0, c, lb = 0, lx = 0, ly = 0, lm = 0;//, tx, ty;
+	int x, y, line_x, line_y, b = 0, sl=1, sr=0, su=0, c, lb = 0, lx = 0, ly = 0, lm = 0;//, tx, ty;
 	int da = 0, dae = 0, db = 0, it = 2047, mx, my, bsx = 2, bsy = 2;
 	float nfvx, nfvy;
 	int load_mode=0, load_w=0, load_h=0, load_x=0, load_y=0, load_size=0;
@@ -3024,11 +3024,23 @@ int main(int argc, char *argv[])
 				{
 					if (lm == 1)//line tool
 					{
-						xor_line(lx, ly, x, y, vid_buf);
+						if (sdl_mod & KMOD_ALT)
+						{
+							float snap_angle = floor(atan2(y-ly, x-lx)/(M_PI*0.25)+0.5)*M_PI*0.25;
+							float line_mag = sqrtf(pow(x-lx,2)+pow(y-ly,2));
+							line_x = (int)(line_mag*cos(snap_angle)+lx+0.5f);
+							line_y = (int)(line_mag*sin(snap_angle)+ly+0.5f);
+						}
+						else
+						{
+							line_x = x;
+							line_y = y;
+						}
+						xor_line(lx, ly, line_x, line_y, vid_buf);
 						if (c==WL_FAN+100 && lx>=0 && ly>=0 && lx<XRES && ly<YRES && bmap[ly/CELL][lx/CELL]==WL_FAN)
 						{
-							nfvx = (x-lx)*0.005f;
-							nfvy = (y-ly)*0.005f;
+							nfvx = (line_x-lx)*0.005f;
+							nfvy = (line_y-ly)*0.005f;
 							flood_parts(lx, ly, WL_FANHELPER, -1, WL_FAN);
 							for (j=0; j<YRES/CELL; j++)
 								for (i=0; i<XRES/CELL; i++)
@@ -3045,8 +3057,8 @@ int main(int argc, char *argv[])
 								for (i=-bsx; i<=bsx; i++)
 									if (lx+i>=0 && ly+j>=0 && lx+i<XRES && ly+j<YRES && ((CURRENT_BRUSH==CIRCLE_BRUSH && pow(i,2)*pow(bsy,2)+pow(j,2)*pow(bsx,2)<=pow(bsx,2)*pow(bsy,2))||(CURRENT_BRUSH==SQUARE_BRUSH&&i*j<=bsy*bsx)))
 									{
-										vx[(ly+j)/CELL][(lx+i)/CELL] += (x-lx)*0.002f;
-										vy[(ly+j)/CELL][(lx+i)/CELL] += (y-ly)*0.002f;
+										vx[(ly+j)/CELL][(lx+i)/CELL] += (line_x-lx)*0.002f;
+										vy[(ly+j)/CELL][(lx+i)/CELL] += (line_y-ly)*0.002f;
 									}
 						}
 					}
@@ -3080,7 +3092,7 @@ int main(int argc, char *argv[])
 				else //it is the first click
 				{
 					//start line tool
-					if ((sdl_mod & (KMOD_LSHIFT|KMOD_RSHIFT)) && !(sdl_mod & (KMOD_LCTRL|KMOD_RCTRL|KMOD_LALT)))
+					if ((sdl_mod & (KMOD_SHIFT)) && !(sdl_mod & (KMOD_CTRL)))
 					{
 						lx = x;
 						ly = y;
@@ -3088,7 +3100,7 @@ int main(int argc, char *argv[])
 						lm = 1;//line
 					}
 					//start box tool
-					else if ((sdl_mod & (KMOD_LCTRL|KMOD_RCTRL)) && !(sdl_mod & (KMOD_LSHIFT|KMOD_RSHIFT)))
+					else if ((sdl_mod & (KMOD_CTRL)) && !(sdl_mod & (KMOD_SHIFT|KMOD_ALT)))
 					{
 						lx = x;
 						ly = y;
@@ -3096,7 +3108,7 @@ int main(int argc, char *argv[])
 						lm = 2;//box
 					}
 					//flood fill
-					else if ((sdl_mod & (KMOD_LCTRL|KMOD_RCTRL)) && (sdl_mod & (KMOD_LSHIFT|KMOD_RSHIFT)) && !(sdl_mod & (KMOD_LALT)))
+					else if ((sdl_mod & (KMOD_CTRL)) && (sdl_mod & (KMOD_SHIFT)) && !(sdl_mod & (KMOD_ALT)))
 					{
 						if (sdl_mod & (KMOD_CAPS))
 							c = 0;
@@ -3110,7 +3122,7 @@ int main(int argc, char *argv[])
 						lm = 0;
 					}
 					//sample
-					else if (((sdl_mod & (KMOD_LALT|KMOD_RALT)) && !(sdl_mod & (KMOD_SHIFT))) || b==SDL_BUTTON_MIDDLE)
+					else if (((sdl_mod & (KMOD_ALT)) && !(sdl_mod & (KMOD_SHIFT|KMOD_CTRL))) || b==SDL_BUTTON_MIDDLE)
 					{
 						if (y>=0 && y<YRES && x>=0 && x<XRES)
 						{
@@ -3169,12 +3181,14 @@ int main(int argc, char *argv[])
 			{
 				x /= sdl_scale;
 				y /= sdl_scale;
+				line_x /= sdl_scale;
+				line_y /= sdl_scale;
 				c = (lb&1) ? sl : sr;
 				su = c;
 				if (lm == 1)//line
 				{
 					if (c!=WL_FAN+100 || lx<0 || ly<0 || lx>=XRES || ly>=YRES || bmap[ly/CELL][lx/CELL]!=WL_FAN)
-						create_line(lx, ly, x, y, bsx, bsy, c);
+						create_line(lx, ly, line_x, line_y, bsx, bsy, c);
 				}
 				else//box
 					create_box(lx, ly, x, y, c);
diff --git a/src/powder.c b/src/powder.c
index e1457c770..2a72fee64 100644
--- a/src/powder.c
+++ b/src/powder.c
@@ -2641,7 +2641,7 @@ int create_parts(int x, int y, int rx, int ry, int c)
 				{
 					i = ox;
 					j = oy;
-					if (((sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_SHIFT))|| ((sdl_mod & (KMOD_CAPS)) && b!=WL_FANHELPER) ))
+					if (((sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_CTRL))|| ((sdl_mod & (KMOD_CAPS)) && b!=WL_FANHELPER) ))
 					{
 						if (bmap[j][i]==SLALT-100)
 							b = 0;
@@ -2673,8 +2673,8 @@ int create_parts(int x, int y, int rx, int ry, int c)
 		return 1;
 	}
 
-	//if SHIFT+ALT or CAPSLOCK is on, specific delete
-	if (((sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_SHIFT))|| sdl_mod & (KMOD_CAPS) )&& !REPLACE_MODE)
+	//if CTRL+ALT or CAPSLOCK is on, specific delete
+	if (((sdl_mod & (KMOD_LALT) && sdl_mod & (KMOD_CTRL))|| sdl_mod & (KMOD_CAPS) )&& !REPLACE_MODE)
 	{
 		if (rx==0&&ry==0)
 		{