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[alway]

Yeah, your sort function is hardwired for 20 elements and you are giving it arrays with size 5. The memory allocation probably* puts arrays 1, 2, and 3 next to one another and sort(array1) simply treats those 3 arrays as a single array and sorts it as such, while sort(array2) takes the values in memory for array 2, array3, and whatever random noise is stored in the 5 positions after the end of array3 as a size 20 array, thus giving you 15 of your numbers and 5 random values from memory. My guess would be your error came from a brainfart involving the size of the array in bites (20) being confused for the size of the array in elements (5).

*memory allocation will usually allocate this way iirc, since they are being created one after the other in code, though automated code optimization or a memory shortage in a specific block of memory allocated to the program may cause them to be stored elsewhere.

[MaximumZero]

The form definition is just a class. The Form in the application is just an object. Add a public member to the form definition of form 2 and set it from form 1.

No matter how many times I read this, I still can't make heads or tails of it. Care to elaborate, oh Zen Master?

[Darvi]

Yeah, your sort function is hardwired for 20 elements and you are giving it arrays with size 5.

Yeah I just figured that out. I simply copied the function from a previous file and didn't even bother to check  :x

[DrKillPatient]

I'm trying to make a basic system for graphical tiles, similar to DF in the way of having (changeable) ASCII tilesets printed out to the screen. I'd like to use a fairly common portable library such as OpenGL or SDL. Does anyone here know of a decent tutorial for such a thing?

[Gatleos]

I'm trying to make a basic system for graphical tiles, similar to DF in the way of having (changeable) ASCII tilesets printed out to the screen. I'd like to use a fairly common portable library such as OpenGL or SDL. Does anyone here know of a decent tutorial for such a thing?

Well, libtcod is made with SDL and just as portable. If you want to make it by scratch, on the other hand:

In my experience, it's dead simple to make a graphics engine to draw ASCII tiles from a bitmap. Everything you need is in SDL's basic blitting functions. The tough part is the colors. In SDL, there's really no "clean" way to tint a surface before drawing it. Every method I could find was either way too slow or way too memory-heavy. So, OpenGL is really the way to go if you want a quick way to draw colored ASCII tiles.

[Virex]

Yeah, your sort function is hardwired for 20 elements and you are giving it arrays with size 5.

Yeah I just figured that out. I simply copied the function from a previous file and didn't even bother to check  :x

Any reason you can't just use a built-in sorting function? Because right now you're using bubble sort, which is kind of the slowest sorting algorithm you're ever going to see (It's O(n²) with a high prefactor. The only reason you ever see it is for didactic reasons)

[Darvi]

Was part of the problem. So  yeah, didactic reasons.

[Virex]

Tell them to teach you something useful then (insertion sort maybe?)

[Darvi]

Quicksort.

[Virex]

For a 20 element array? Well, if the alternative is bubble sort it makes sense...

[alfie275]

If you're doing tiles in opengl you might want to just use textured quads.

[DrKillPatient]

If you're doing tiles in opengl you might want to just use textured quads.

I'm not at all familiar with OpenGL-- is that essentially creating a row of squares along the screen (each the size of one tile on the tileset bitmap) and retexturing them as needed?

[Shades]

Quicksort.

Dual-pivot Quicksort, that extra ~20% efficiency over those huge 20 element lists might save you whole cycles

[Darvi]

Boggosort is best sort.

And now I have to PM scriver that typo.

[malloc]

If you're doing tiles in opengl you might want to just use textured quads.

I'm not at all familiar with OpenGL-- is that essentially creating a row of squares along the screen (each the size of one tile on the tileset bitmap) and retexturing them as needed?

Yes pretty much, but:
Each tile only need a texture coordinate to where relative in the texture where the tile is located.
Texture swapping is one of the biggest bottlenecks in graphics rendering, which is why you will want to try to do it as rarely as possible.

This is pretty much what I did in my openGL games:

Code: [Select]

//Usually I render everything to a framebuffer, but it is not really necessary.
...
for(int i = 0; i < screen_width/tile_width ; ++i){
    for(n = 0; n < screen_height/tile_height ; ++n){
        glBegin(GL_QUADS);
        glTexCoord2f(map.tiles[i,n].xOffset[0],map.tiles[i,n].yOffset[0]);
        glVertex3f(i*tile_width,n*tile_width,0);
        glTexCoord2f(map.tiles[i,n].xOffset[1],map.tiles[i,n].yOffset[1]);
        glVertex3f(i*tile_width+tile_width,n*tile_width,0);
        glTexCoord2f(map.tiles[i,n].xOffset[2],map.tiles[i,n].yOffset[2]);
        glVertex3f(i*tile_width+tile_width,n*tile_width+tile_height,0);
        glTexCoord2f(map.tiles[i,n].xOffset[3],map.tiles[i,n].yOffset[3]);
        glVertex3f(i*tile_width,n*tile_width+tile_height,0);
        glEnd();
    }
}