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DeveloperX
202192397
Joined: 04 May 2003
Posts: 1626
Location: Decatur, IL, USA
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 Posted: Sat Aug 22, 2009 7:20 am Post subject: |
[quote] |
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I use SDL_TTF in my map editor.
One sec...
My init code is
| Code: |
if (-1 == TTF_Init())
{
fprintf(stderr, "Unable to initialize SDL_TTF!\nSDL_TTF Error: %s\n", TTF_GetError());
return false;
}
editorfont = TTF_OpenFont("silkscreen.ttf", 8);
if (!editorfont)
{
fprintf(stderr, "Unable to load \"silkscreen.ttf\"!\nSDL_TTF Error: %s\n", TTF_GetError());
return false;
}
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and here is a function that will make things easier
| Code: |
void editor_printf(int x, int y, unsigned int color, const char* format, ...)
{
char textbuffer[0x100];
va_list args;
va_start(args, format);
vsprintf(textbuffer, format, args);
SDL_Color c;
Uint8 r, g, b;
SDL_GetRGB(color, editorscreen->format, &r, &g, &b);
c.r = r;
c.g = g;
c.b = b;
SDL_Surface* textsurface = TTF_RenderText_Solid(editorfont, textbuffer, c);
if (textsurface)
{
SDL_Rect dst;
dst.x = x;
dst.y = y;
SDL_BlitSurface(textsurface, 0, editorscreen, &dst);
SDL_FreeSurface(textsurface);
}
va_end(args);
}
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here is an example of how to use it
| Code: |
editor_printf(
editortilewidth + 4,
editortileheight - 14,
editortextcolor,
"%s | Mouse Tile X %3d/%3d | Mouse Tile Y %3d/%3d | Camera X %3d | Camera Y %3d | "
"Camera Width %2d | Camera Height %2d | Tile 0x%04X",
(EditorBGEdit==editormode)?"Background Edit Mode":
(EditorFGEdit==editormode)?"Foreground Edit Mode":"Collision Edit Mode",
editormousetilex, editorlevel->width,
editormousetiley, editorlevel->height,
editorcamera->intiles->x, editorcamera->intiles->y,
editorcamera->intiles->w, editorcamera->intiles->h, editorcurrentile);
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if you have any questions, feel free to ask me. :)
oh..
the variables are
| Code: |
TTF_Font* editorfont;
unsigned int editortextcolor =SDL_MapRGB(editorscreen->format, 255, 255, 255);
|
if you need anything, let me know
_________________
Principal Software Architect
Rambling Indie Games, LLC
See my professional portfolio
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Nodtveidt
Demon Hunter
Joined: 11 Nov 2002
Posts: 786
Location: Camuy, PR
|
| Posted: Sat Aug 22, 2009 10:58 am Post subject: |
[quote] |
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I had some trouble with SDL_TTF at first as well...there really is a severe shortage of proper tutorials for it. But once you get it it's pretty easy...it simply renders text starting at the top left of the surface you're rendering to, then you simply blit that surface onto your screen surface or wherever you want it.
Rich, that's a pretty interesting function. A couple of things I wanna know though...
-Any particular reason you use -1 == TTF_Init()? Is this an optimization technique? I've seen such things before but wondered if this is one of them.
-Also, why do you create and destroy the surface in the function? I would figure this is additional overheard that you don't need; I just create the text render surface as a global and destroy it on exit.
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If you play a Microsoft CD backwards you can hear demonic voices. The scary part is that if you play it forwards it installs Windows. - wallace
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DeveloperX
202192397
Joined: 04 May 2003
Posts: 1626
Location: Decatur, IL, USA
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| Posted: Sat Aug 22, 2009 9:07 pm Post subject: |
[quote] |
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| Nodtveidt wrote: |
Rich, that's a pretty interesting function. A couple of things I wanna know though...
-Any particular reason you use -1 == TTF_Init()? Is this an optimization technique? I've seen such things before but wondered if this is one of them.
-Also, why do you create and destroy the surface in the function? I would figure this is additional overheard that you don't need; I just create the text render surface as a global and destroy it on exit. |
It is because that is what determines if there was an error with initializing SDL_TTF.
See documentation:
3.1.2 TTF_Init
int TTF_Init()
Initialize the truetype font API.
This must be called before using other functions in this library, excepting TTF_WasInit.
SDL does not have to be initialized before this call.
Returns: 0 on success, -1 on any error
The overhead from the surface creation isn't that bad actually.
You could create a single "scratch pad" surface outside the main loop and clear it, and then write on it each time, however I find that SDL copes with creation/deletion of a surface faster than it takes to clear an existing surface.
One of the little things I came across while writing my map editor.
I got it from 2FPS to 40FPS by changing several things that I did.
That was one change that gave me about a 10FPS difference.
_________________
Principal Software Architect
Rambling Indie Games, LLC
See my professional portfolio
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Nodtveidt
Demon Hunter
Joined: 11 Nov 2002
Posts: 786
Location: Camuy, PR
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| Posted: Sun Aug 23, 2009 2:44 am Post subject: |
[quote] |
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| DeveloperX wrote: | | It is because that is what determines if there was an error with initializing SDL_TTF. |
That is not what I meant. I was referring to the order in which your comparison was done. You have the value to the left, and the function to the right. It is typically done the other way around. I wanted to know if you had a particular purpose for doing it the way you did it.
_________________
If you play a Microsoft CD backwards you can hear demonic voices. The scary part is that if you play it forwards it installs Windows. - wallace
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DeveloperX
202192397
Joined: 04 May 2003
Posts: 1626
Location: Decatur, IL, USA
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| Posted: Sun Aug 23, 2009 3:20 am Post subject: |
[quote] |
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Oh that!
Yes. In fact. A very good reason.
Its a very common and frustrating typo to use an assignment operator when you meant an equality comparison operator.
By using the value on the left hand side, you avoid every having to worry about frustrating bugs from that typo.
Because an assignment operator will compile if the left hand side contains a variable.
| Code: |
int a = 5;
if (a = 5) { fprintf(stdout, "a is equal to five!\n"); } // logic bug
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versus
| Code: |
int a = 5;
if (5 = a) { fprintf(stdout, "a is equal to five!\n"); } // error
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The latter is much better because then the compiler will point out your typo.
| Code: |
int a = 5;
if (5 == a) { fprintf(stdout, "a is equal to five!\n"); } // correct
|
_________________
Principal Software Architect
Rambling Indie Games, LLC
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Nodtveidt
Demon Hunter
Joined: 11 Nov 2002
Posts: 786
Location: Camuy, PR
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| Posted: Mon Aug 24, 2009 12:12 am Post subject: |
[quote] |
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Interesting...I can see the advantage, especially if switching back and forth between BASIC and C.
_________________
If you play a Microsoft CD backwards you can hear demonic voices. The scary part is that if you play it forwards it installs Windows. - wallace
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DeveloperX
202192397
Joined: 04 May 2003
Posts: 1626
Location: Decatur, IL, USA
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Captain Vimes
Grumble Teddy
Joined: 12 May 2006
Posts: 225
Location: The City Streets
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| Posted: Wed Aug 26, 2009 3:39 pm Post subject: |
[quote] |
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Thanks for the TTF help, guys. I haven't quite reached that point in the programming process yet, but I will soon. This will really help a lot.
_________________
"Sometimes it is better to light a flamethrower than to curse the darkness."
- Terry Pratchett
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DeveloperX
202192397
Joined: 04 May 2003
Posts: 1626
Location: Decatur, IL, USA
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