C Snippets/Help Section

[Slasher]

So...your new to coding and you don't know where to start? Some great tutorials by 'Yeldarb' have been written for people in your position. His tutorials cover everything from setting up your development environment, right into displaying your first image on-screen. His tutorials even go into enough depth as to show you how to get MP3s running within your games!

His tutorials can be seen on the following pages:
[Only registered and activated users can see links. ]
[Only registered and activated users can see links. ]
[Only registered and activated users can see links. ]
[Only registered and activated users can see links. ]
[Only registered and activated users can see links. ]
[Only registered and activated users can see links. ]



And now...some snippets of code in C you may find useful:
(more to come)

USB MODE
By: Slasher

Headers:

 
#include <pspkernel.h>
#include <pspdisplay.h>
#include <pspusb.h>
#include <pspusbstor.h>
#include <string.h>

Functions:

 
// Defines
#define     printf     pspDebugScreenPrintf

// Functions
int LoadStartModule(char *path) {
     u32 loadResult;
     u32 startResult;
     int status;
     loadResult = sceKernelLoadModule(path, 0, NULL);
 
     if (loadResult & 0x80000000) return -1;
     else
     startResult = sceKernelStartModule(loadResult, 0, NULL, &status, NULL);
 
     if (loadResult != startResult) return -2;
 
     return 0;
}
 
void initUSB() {
     u32 retVal;
     LoadStartModule("flash0:/kd/semawm.prx");
     LoadStartModule("flash0:/kd/usbstor.prx");
     LoadStartModule("flash0:/kd/usbstormgr.prx");
     LoadStartModule("flash0:/kd/usbstorms.prx");
     LoadStartModule("flash0:/kd/usbstorboot.prx");
 
     retVal = sceUsbStart(PSP_USBBUS_DRIVERNAME, 0, 0);
 
     if (retVal != 0) {
          printf("Error starting USB Bus driver (0x%08X)\n", retVal);
          sceKernelSleepThread();
     }
 
     retVal = sceUsbStart(PSP_USBSTOR_DRIVERNAME, 0, 0);
 
     if (retVal != 0) {
          printf("Error starting USB Mass Storage driver (0x%08X)\n", retVal);
          sceKernelSleepThread();
     }
 
     retVal = sceUsbstorBootSetCapacity(0x800000);
 
     if (retVal != 0) {
          printf("Error setting capacity with USB Mass Storage driver (0x%08X)\n", retVal);
          sceKernelSleepThread();
     }
 
     retVal = 0;
}
 
void usbMode(char * what) {
     u32 retVal;
     if (stricmp(what, "on")==0) {
          retVal = sceUsbActivate(0x1c8);
     }
     else if (stricmp(what, "off")==0) {
          retVal = sceUsbDeactivate();
     }
}

Call this just inside of your int main:

initUSB();

Example:

usbMode("on");
 
or
 
usbMode("off");

Put this in your 'Makefile':

In LIBS=
-lpspusb -lpspusbstor

FADE SPLASH SCREEN
By: Samstag

Headers:
Your going to need to follow the tutorials [Only registered and activated users can see links. ] to get basic images blitting with graphics.c/h and framebuffer.c/h
Your going to also need [Only registered and activated users can see links. ] files.

#include <pspdisplay.h>
#include <pspctrl.h>
#include <pspkernel.h>
#include <pspdebug.h>
#include <pspgu.h>
#include <png.h>
#include <stdio.h>
#include "graphics.h"
#include "framebuffer.h"

Functions:

 
/*
Features:
- Modifies an entire image for fading effects 
- Takes a percentage input of 0 (transparent) to 100 (opaque)
 
Inputs:
- Image* image - valid Image pointer from the loadImage(filename) function in Yeldarb's tutorial #4 
- unsigned char alpha - a number from 0-100
*/
void set_image_alpha(Image *image, unsigned char alpha) {
     int i, size;
     Color *pixel;
     unsigned int alpha_mod;
 
     if(!image || !image->data) return;
 
     size = image->textureWidth * image->textureHeight;
     pixel = image->data;
 
     if(alpha > 100) alpha = 100;
 
     alpha_mod = ((alpha * 255) / 100) << 24;
 
     for(i = 0; i <= size; i++) {
          *pixel = (*pixel & 0x00ffffff) | alpha_mod;
          pixel++;
     }
}
 
/*
Features:
- Centers undersized images on a black background 
- Fades in the image at a rate you set 
- After fade-in, it will wait X seconds or any button press
 
Inputs:
- Image* pic - a valid Image pointer from the loadImage(filename) function in Yeldarb's tutorial #4 
- int fade_rate - the speed to fade the image in (higher = faster) 
- int timeout - time in seconds to display the image after the fade is complete
*/
void show_splash(Image *pic, int fade_rate, int timeout) {
     int i, delay_time;
     int x_offset = 0, y_offset = 0;
     SceCtrlData input;
 
     delay_time = 40000;
     timeout = (timeout * 1000000) / delay_time;
 
     if(pic->imageWidth < 480) x_offset = (480 - pic->imageWidth) / 2;
     if(pic->imageHeight < 480) y_offset = (272 - pic->imageHeight) / 2;
 
     if(pic) {
          for(i = 0; i <= 100; i += fade_rate) {
               set_image_alpha(pic, i);
               clearScreen(0);
               blitAlphaImageToScreen(0, 0, pic->imageWidth, pic->imageHeight,
pic, x_offset, y_offset);
 
                flipScreen();
                sceKernelDelayThread(delay_time);
          }
 
          for(i = 0; i < timeout; i++) {
               sceCtrlReadBufferPositive(&input, 1);
               if(input.Buttons) break;
               sceKernelDelayThread(delay_time);
          }
     }
}

Example:

Image* intro1;
Image* intro2;
 
intro1 = loadImage("title_screen.png");
intro2 = loadImage("credits_screen.png");
 
if(intro1) {
     show_splash(intro1, 8, 4);
     freeImage(intro1);
}
 
if(intro2) {
     show_splash(intro2, 8, 4);
     freeImage(intro2);
}

Put this in your 'Makefile':

 
In OBJS=
graphics.o framebuffer.o
 
In LIBS=
-lpspgu -lpng -lz -lm

[Chossy.]

here's a simple code.

this will load a bg pic for your program


#include<pspdisplay.h>
#include<pspctrl.h>
#include<pspkernel.h>
#include<pspdebug.h>
#include<pspgu.h>
#include<png.h>
#include<stdio.h>
#include"graphics.h"

#define printf pspDebugScreenPrintf
#define MAX(X, Y) ((X) > (Y) ? (X) : (Y))
PSP_MODULE_INFO("Image Display Program", 0, 1, 1);

/* Exit callback */
int exit_callback(int arg1, int arg2, void *common) {
sceKernelExitGame();
return 0;
}
/* Callback thread */
int CallbackThread(SceSize args, void *argp) {
int cbid;
cbid = sceKernelCreateCallback("Exit Callback", exit_callback, NULL);
sceKernelRegisterExitCallback(cbid);
sceKernelSleepThreadCB();
return 0;
}
/* Sets up the callback thread and returns its thread id */
int SetupCallbacks(void) {
int thid = 0;
thid = sceKernelCreateThread("update_thread", CallbackThread, 0x11, 0xFA0, 0, 0);
if(thid >= 0) {
sceKernelStartThread(thid, 0, 0);
}
return thid;
}
int main() {

pspDebugScreenInit();
SetupCallbacks();
initGraphics();

// Draw BG Pic
char buffer[200];
Image* ourImage;
sprintf(buffer, "ms0:/loader/backpic.png"); // this prevents a buffer overflow
ourImage = loadImage(buffer);
sceDisplayWaitVblankStart();
blitAlphaImageToScreen(0 ,0 ,480 , 272, ourImage, 0, 0);
flipScreen();
// Next
sceKernelSleepThread();
return 0;
}



regards

chossy

[bronxbomber92]

Ahhh, damn! Yeldarb's tut aren't loading... anyone have a backup?

[CT_Bolt]

Originally Posted by Bronxbomber92

Ahhh, damn! Yeldarb's tut aren't loading... anyone have a backup?

[Only registered and activated users can see links. ]