Blade_punk's Tutorials and Samples

[Blade_punk]

Hey,
Sabre requested some info on reading and writing to a file earlier today so i decided to write this tutorial up.

Source+binary can be downloaded here:
http://www.sendspace.com/file/wdc8br
It was coded quickly but it shouldn't be too bad. I used sceIo functions instead of the virtaul filesystem ones because I found that the ones built into OSLib use stdio.h.

Also, a quick function i forgot to add:

char write_buffer[128*1024];
void write_file(const char *readpath, const char *writepath)
{
	int fdin;
	int fdout;
	fdin = sceIoOpen(readpath, PSP_O_RDONLY, 0777);
	if(fdin >= 0)
	{
		int bytesRead = 1;
		fdout = sceIoOpen(writepath, PSP_O_WRONLY | PSP_O_CREAT | PSP_O_TRUNC, 0777);
		bytesRead = sceIoRead(fdin, write_buffer, sizeof(write_buffer));
		while((bytesRead > 0) && (fdout >= 0))
		{
			sceIoWrite(fdout, write_buffer, bytesRead);
			bytesRead = sceIoRead(fdin, write_buffer, sizeof(write_buffer));
		}

		if(fdout >= 0)
		{
			sceIoClose(fdout);
		}

		if(fdin >= 0)
		{
			sceIoClose(fdin);
		}
	}
}

I take no credit for that function, it was made by Slasher.

Sorry for the late posting by the way, Sabre. I got caught up doing things.

-----------------

Simple Menu Source
I also made a simple menu source to help out some of the newbies. Its relatively simple to understand and isn't too bad. It contains 2 loops, one within the other. It blits the menu then enters the second loop and waits for a button to be pressed. If the user presses a button it breaks the loop and updates the menu so it isnt constantly printing.

Link:
http://www.sendspace.com/file/6rwyp2

------------------

Splitting your source into multiple files

Well everyone knows it can get hard working out of one file, your main.c. Finding functions can be difficult and everything gets harder when navigating through it. In this tutorial I'll give you a quick rundown on how to break your program up into separate files so its waaaay easier to manage.
First of all, say we have a source file called 'Add.c" that contains:

int plus(int a, int b)
{
	return a+b;
}

We begin by creating a new source file called 'Add.h'. This is going to contain info about our source (*.c) file. Add the very top of the file we add:

#ifndef __ADD__
#define __ADD__

This begins our header. Now we simply put the first line of our function:

int plus(int a, int b);//Add a ';'

Here you add all of the 'descriptions' i guess you could call them of your functions from your source file like what we've just done. Finish of the file by adding:

#endif

So our whole Add.h file is:

#ifndef __ADD__
#define __ADD__

int plus(int a, int b);//Add a ';'

#endif

From here add

Add.h

to the top of Add.c and any other file thats going to be using functions from Add.c. After that simply put 'Add.o' to your OBJS line in your makefile and your finished.

Binary + source:
http://www.sendspace.com/file/gzx6xq

------------------

Heres a really basic batch file that can be pretty handy for quick testing if your not using PSPLink:

make clean
make
MOVE .\EBOOT.PBP *Your PSP's drive letter*:\PSP\GAME\*Name of your program*\EBOOT.PBP
make clean
cmd

Simply copy that into an empty text file and save as something like compile.bat. Now after you've edited your source and want to test on your PSP, just open the file or type 'compile'
into a command prompt and it will compile your program, copy the eboot.pbp to your PSP and then clean up everything. Saves you going My Computer, *PSP drive*, PSP, GAME .etc constantly on only copies what you need.
------------------
Fading In and Out
Presentation is a big part of a program if your aiming to make the best one around. Simply using fading can make your app look waaaay better. Here are the functions:

int transp;//Fo transparency
OSL_COLOR *fade;//To hold the colour of the rectangle blitted

void fadeOut(OSL_IMAGE* bg)//Name and params taken
{
	for(transp = 0; transp < 255; transp += 3)//Sets the transparency to 0 aka invisible. Then it increases by 3 until it equals 255 aka completely visible
	{
		oslStartDrawing();//Start drawing
		fade = RGBA(0, 0, 0, transp);//Set the colour of the rectangle. Sets the alpha to what transp currently is
		oslDrawImage(bg);//Draws an image in the background
		oslDrawFillRect(0, 0, 480, 272, fade);//Draws the rectangle over the screen
		oslEndDrawing();//Finish drawing
		oslEndFrame();//End the current frame
    	oslSyncFrame();//Sync everything
	}
}
void fadeIn(OSL_IMAGE* bg)//Name and params taken
{
	for(transp = 255; transp > 0; transp -= 3)//Sets the transparency to 255 aka completely visible. Then it decreases by 3 until it equals 255 aka invisible
	{
		oslStartDrawing();//Start drawing
		fade = RGBA(0, 0, 0, transp);//Set the colour of the rectangle. Sets the alpha to what transp currently is
		oslDrawImage(bg);//Draws an image in the background
		oslDrawFillRect(0, 0, 480, 272, fade);//Draws the rectangle over the screen
		oslEndDrawing();//Finish drawing
		oslEndFrame();//End the current frame
    	oslSyncFrame();//Sync everything
	}
}

They're made for OSLib but can be easily ported
------------------
Triangle function
Heres an easy to use triangle function for OSLib.

void oslDrawFillTri(int x0, int y0, int x1, int y1, int x2, int y2, OSL_COLOR color)
{
		OSL_LINE_VERTEX* vertices;

		vertices = (OSL_LINE_VERTEX*)sceGuGetMemory(3 * sizeof(OSL_LINE_VERTEX));
		
		//Goes counter clockwise
		vertices[0].color = color;
		vertices[0].x = x0;
		vertices[0].y = y0;
		vertices[0].z = 0;

		//The middle point
		vertices[1].color = color;
		vertices[1].x = x1;
		vertices[1].y = y1;
		vertices[1].z = 0;

		vertices[2].color = color;
		vertices[2].x = x2;
		vertices[2].y = y2;
		vertices[2].z = 0;

		sceGuDisable(GU_TEXTURE_2D);
		sceGuDrawArray(GU_TRIANGLE_STRIP, GU_COLOR_8888|GU_VERTEX_16BIT|GU_TRANSFORM_2D, 3, 0, vertices);
		sceGuEnable(GU_TEXTURE_2D);
}

------------------

Simple Shooting Source
Contains a basic shooting for upto 5 bullets. Pretty easy to read and modify
http://www.sendspace.com/file/mz0u3d

[pirata nervo]

pretty cool tutorial blade punk ;)

[InsertWittyName]

I would recommend removing all the oslib dependent parts in the file io tutorial so anyone can use it and add error checking, you don't do any!

[Blade_punk]

Originally Posted by InsertWittyName

I would recommend removing all the oslib dependent parts in the file io tutorial so anyone can use it and add error checking, you don't do any!

Oh my, i didnt did I :o lol, i didnt even realise. I'll add that in and remove the OSLib code when I re-do it tonight

[Dark_Sabre]

Thank you blade punk, like I said, your always there to help :)

[Brick]

I also suggest allocating memory for read/write buffers
dynamically.

Also , you might want to end up writting a small "library",that will look like
this:

void openFile(SceUID file_handle,const char* filename,flags..?)
void closeFile(file_handle);
void writeFile(file_handle,const char* buf);
void readFile(file_handle,char** buf);

Usage:

SceUID file;
openFile(file...,"text.txt",..)

char* readbuf=NULL;

readFile(file,readbuf);
free(readbuf)//allocated dynamically by "readFile" function
closeFile(file)

//write something:
openFile(file...,"text.txt",..)
writeFile(file,"1..23..4\n");
writeFile(file,"hey!...");
closeFile(file);

[Blade_punk]

I was thinking about making a library to simplify it. Might work on it after I've uploaded the commented source

Thanks for the feedback

Edit:
Source now commented and doesnt use OSLib (check out the size difference in the file!).

Edit 2:
I got bored so i added a tutorial on how to split up your source files. Explained really badly but should give you an idea

[Blade_punk]

Binary and source code uploaded for source splitting tut

Edit:
Updated first post with a basic batch file for compiling your program, copying it to your PSP and then cleaning up everything

[pirata nervo]

did you put this in the mega thread?

[Blade_punk]

Its in there but under other stuff.

I guess I'll move it up to tutorials now

Edit:
Added fading functions