Scratch

Colour based sensing is MUCH faster than normal sensing, becuse it doesn't have to detect for pixel perfect collision for all the sprites to be collided with.

The "If Touching" Block lags. A lot. With pixel perfect sensing comes a hefty price, speed. You may have noticed that games that use a lot of hit-tests (archmage games) run slowly outside presentation mode because of this.

Array based sensing is very impractical in scratch. Why? Because of lack of support for multi-dimentional arrays. People have to emulate multidimensional arrays, which also comes at a price.

There is a method where you have a sprite with a costume without the color sensing, and a costume that has the color sensing over it.  Start it with the costume on color sensing, implement the sense scripts, and switch it back to the normal costume.

It's fast, its easy, and it doesn't have those weird colors over it.

Problem solved 

Last edited by Kileymeister (2010-01-11 16:54:22)

It is innacurate sometimes, but its pretty useful.

RHY3756547 wrote:

And also I hate how everyone uses Hit-tests. You DO NOT ever need them.

Just move x-velocity, check for X-collisions then move Y-velocity, check for Y collisions. You can get whether it's up/down from the starting veloicity.

I noticed that when i was programming NinjaX

Kileymeister wrote:

RHY3756547 wrote:

Kileymeister wrote:

There is a method where you have a sprite with a costume without the color sensing, and a costume that has the color sensing over it.  Start it with the costume on color sensing, implement the sense scripts, and switch it back to the normal costume.

It's fast, its easy, and it doesn't have those weird colors over it.

Problem solved 

Aha - but everything that happens in scratch has a cost. Switching costumes is one of them.

Yeah, but its instantaneous.  No one notices. At least with my method its instantaneous.  How is switching costumes a cost?

The scratch engine has to interpret mode code AND it has to rerender the scene. With enough, the game will become jittery.

Last edited by RHY3756547 (2010-01-11 17:08:16)

RHY3756547 wrote:

Colour based sensing is MUCH faster than normal sensing, becuse it doesn't have to detect for pixel perfect collision for all the sprites to be collided with.

The "If Touching" Block lags. A lot. With pixel perfect sensing comes a hefty price, speed. You may have noticed that games that use a lot of hit-tests (archmage games) run slowly outside presentation mode because of this.

Array based sensing is very impractical in scratch. Why? Because of lack of support for multi-dimentional arrays. People have to emulate multidimensional arrays, which also comes at a price.

You know too much. Shoo shoo away!    j/k

But lolz is this basically common knowledge for every programming language? Because you sure know a lot lolz >.>

Based on what I've read so far, your new motto is "which comes at a price". Seriously it feels like you've said that 3 times.

Last edited by Lucario621 (2010-01-11 17:13:03)

Colour sensing is good if the colour doesn't look out of place. If you have purple lines everywhere then it looks unprofessional.

Sprite based sensing is good for testing collisions at specific points but it does lag a bit.

Array sensing is good for many programming languages, but not scratch. There is no reason I can think of to use array based sensing in large scrolling levels. Its hard to code and laggy.

I've used color collision in Sphered, PapiJump, and iCopter. I find it more useful, as I want to try and eliminate lag in my games.

RHY3756547 wrote:

And also I hate how everyone uses Hit-tests. You DO NOT ever need them.

Just move x-velocity, check for X-collisions then move Y-velocity, check for Y collisions. You can get whether it's up/down from the starting veloicity.

I think that it may be my fault that people use those, since a lot of people learn how to do that from my projects. The reason I do collisions like that is because that is how I learned how to make collisions for platformers in actionscript. In actionscript there is a command called a shapeflag hit test that lets you check for collisions at specific coordinates. Since scratch doesn't have a shape flag hit test or something similar I used sprites.

Sorry for promoting sloppy code, maybe you can code a platformer engine that doesn't use sprites for collisions and I can refer people to that one instead.

floatingmagictree wrote:

I've used color collision in Sphered, PapiJump, and iCopter. I find it more useful, as I want to try and eliminate lag in my games.

Except I didn't like Sphered because you didn't change the costume from color-sensing to regular and back or make it roll. >.> I liked fg123's method.

that's why you should use both color and sprite sensing. if there's like a fighting game, and you put 'if touching sprites', when you're attacking, and the opponent also happens to attack like 2 seconds later, you'll both be considered hit.