Sprite shadow

[MBitt]

I found this script on the web, had no authors name only it was created 6/13/03. It is very good but it slows the game down alot. Can this be fixed?
script:
scr_shadow
{
var temp_x, X, temp_y, Y, temp_color;
temp_color = brush_color;
brush_color = c_black;
for (temp_x = bbox_left; temp_x <= bbox_right; temp_x += 1;)
for (temp_y = bbox_top; temp_y <= bbox_bottom; temp_y += 1;)
{
X = temp_x + ((-(temp_y-y) + bbox_bottom-y))*1;
Y = temp_y;
if (position_meeting(temp_x,temp_y,self))
draw_pixel(X,Y);
}
brush_color = temp_color;
}
object:
draw
{
scr_shadow();
draw_sprite(sprite_index,-1,x,y);
}#nosmileys#nosmileys

[IsmAvatar]

below the posting box there is the "Check this if you'll be adding code (or don't like smileys)." checkbox.

I've done it for you.

[MBitt]

OK it appears that screen redrawing can not be accelerated, what if this code were used as a utility program. Make a rendering program that you inserted your sprite then dump your screen into a different BMP file each sprite frame. Then reconstruct your sprite with the new shadow.

[IsmAvatar]

No idea what you're talking about, but I shrunk down the script a bit. This may speed up game play, but only by a fraction of a frame every second...

script:
scr_shadow
_color = brush_color
brush_color = c_black
for (_x = bbox_left; _x <= bbox_right; _x += 1)
for (_y = bbox_top; _y <= bbox_bottom; _y += 1) {
 X = _x + (-(_y-y) + bbox_bottom-y)
 Y = _y;
 if position_meeting(_x,_y,self)
 draw_pixel(X,Y)
}
brush_color = _color
object:
drawscr_shadow()
draw_sprite(sprite_index,-1,x,y)

the reason for the slowdown is because of "draw_pixel(X,Y)"
drawing a bunch of pixels becomes considerably slow. you could try creating particles instead, but that would be a bit too advanced...

best bets: make a second sprite... much faster.

[MBitt]

Do you mean upload the same sprite again, paint it black and attach it to the first sprite at an angle to simulate the shadow effect?
Not a bad idea. Thanks.

[IsmAvatar]

erm, that wasn't sarcasm, was it? can't tell on the internet.

yeah, that's the method i'd normally use.

[MBitt]

I have never used two sprites together like that before. Learn new things everyday. I guess I could just use a little black shadow sprite instead of each individual sprite being reproduced and darkened. Would save space.

[Flashback]

I can actually make this incredibly fast...

I'll edit with the script later.


EDIT:

---

//Flashback's shadow script
//Designed for a 24x32 sprite - change as needed

pen_color = c_black
brush_color = c_black

//you can also change the brush style using brush_style, but it doesn't look terribly good

draw_ellipse(char.x,char.y+25,char.x+24,char.y+36)
//change"char" to your character/object's name. also, change the drawing settings for the ellipse, as it needs to be adapted to your sprite's dimensions

//© 2004 to Flashback. All Rights Reserved. If you claim this script as yours, you will be subject to hanging.

---

This script is designed for a sprite that is 24x32. modify as needed, but please keep the comments in.#nosmileys#nosmileys

[IsmAvatar]

draw event of character:

push_graphics_settings()
pen_color = c_black
brush_color = c_black
draw_ellipse(x,y+sprite_height-sprite_height/32,x+sprite_width,y+sprite_height+sprite_height/32)
draw_sprite(sprite_index,image_single,x,y)
pop_graphics_settings()

allows for any size sprite, draws a circle somewhat proportionate to the character's height. Change the /32 to /16 or something else if you don't think the proportion is right.

This script based off of Flashback's script, but greatly improved by Ism.

Note, that when GM 6 comes out, drawing functions should be much faster, so the first script posted here should work at a fine speed.

[Flashback]

wow, thanks for the update ism! Mind if I upload the improved version to my site?

[IsmAvatar]

With credit, please.

[Flashback]

uploading...