A little example app to my previous post: #WebOS-HowTo: Make your 2D SDL app @Palm Pixi compatible.

As promised I created a small example app which will show you a running example of how to make your 2D SDL app compatible with Pixi. Here it come, the source and also a complete (Windows VC++-based) project:


#include 
#include  $#include #include #include #include "SDL.h"
#include "PDL.h"
#include "SDL_ttf.h"
#include "SDL_image.h"
#include "SDL_mixer.h"


#define GL_BGR  0x80E0
#define GL_BGRA 0x80E1

#ifdef _WINDOWS
	#define FONT "C:\\WINDOWS\\Fonts\\Arial.ttf"
#else
	#define FONT "/usr/share/fonts/PreludeCondensed-Medium.ttf"
#endif


//Surfaces
SDL_Surface* Surface;
SDL_Surface* Render;
SDL_Surface* screen;
TTF_Font *font_normal = NULL;
Mix_Chunk *explosion_sound = NULL;
GLuint texture;

int x, y;
double v_x;
double v_y;
double a_x;
double a_y;

//Misc
PDL_ScreenMetrics screenMetrics;
SDL_Event sdlEvent;

void MyFillRect(int x, int y, int w, int h, int r, int g, int b, SDL_Surface* screen)
{
	SDL_Rect rect = {x, y, w, h};
	SDL_FillRect(screen, &rect, 0xff000000 | (r < < 16) | (g << 8) | b);
}

SDL_Surface *CreateSurface(Uint32 flags, int w, int h)
{
	return SDL_CreateRGBSurface(flags, w, h, Surface->format->BitsPerPixel, Surface->format->Rmask, Surface->format->Gmask, Surface->format->Bmask, Surface->format->Amask);
}

void UpdateDisplay(SDL_Surface *surface)
{
#ifdef _WIN32
	SDL_Flip(surface);
#else
	int mode;

	glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	if (surface->format->BytesPerPixel == 3) { // RGB 24bit
		mode = GL_BGR;
	} else if (surface->format->BytesPerPixel == 4) { // RGBA 32bit
		mode = GL_BGRA;
	}
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexImage2D(GL_TEXTURE_2D, 0, mode, surface->w, surface->h, 0, mode, GL_UNSIGNED_BYTE, surface->pixels);

	GLfloat box[] = {0,surface->h,0, surface->w,surface->h,0, surface->w,0,0, 0,0,0};
	GLfloat tex[] = {0,1, 1,1, 1,0, 0,0};
	glVertexPointer(3, GL_FLOAT, 0, box);
	glTexCoordPointer(2, GL_FLOAT, 0, tex);
	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);

	glFlush ();
	SDL_GL_SwapBuffers();
#endif
}

void ApplySurface( int x, int y, SDL_Surface* source, SDL_Surface* destination )
{
	if (!source)
		return;

	//Holds offsets
	SDL_Rect offset;
	
	//Source rect
	SDL_Rect src;
	
	//Get offsets
	offset.x = x;
	offset.y = y;
	
	src.x = 0;
	src.y = 0;
	src.w = source->w;
	src.h = source->h;
	
	//Blit
	SDL_BlitSurface( source, &src, destination, &offset );
}

void DisplayString(char *text, int left, int top, int width, int height, SDL_Color clr1, SDL_Color clr2)
{
	MyFillRect(left, top, width, height, clr1.r, clr1.g, clr1.b, screen);

    SDL_Color color = clr2;
	SDL_Surface *nr0 = TTF_RenderText_Blended( font_normal, text, color );
	if (nr0)
	{
		ApplySurface( left + (width-nr0->w)/2, top + (height-nr0->h)/2, nr0, screen );
		SDL_FreeSurface(nr0);
	}
}

void DrawScreen()
{
	bool result = true;

	//Clear the entire screen
	MyFillRect(0, 0, screenMetrics.horizontalPixels, screenMetrics.verticalPixels, 0, 0, 0, screen);

	//Draw a square
	MyFillRect(x, y, 20, 20, 255, 255, 255, screen);
}

int main(int argc, char** argv)
{
	SDL_Joystick *gJoystick;
	bool bInitialUpdate = true;
	double initial_x = 0.0;
	double initial_y = 0.0;

	//Init
    SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_JOYSTICK);
    PDL_Init(0);

	Mix_Init(0);
	Mix_OpenAudio(44100, AUDIO_S16SYS, 2, 1024);
	Mix_AllocateChannels(20);
	Mix_Volume(-1, 64);

	explosion_sound = Mix_LoadWAV("firework.wav");

	TTF_Init();
	font_normal = TTF_OpenFont( FONT, 11 );
	TTF_SetFontStyle(font_normal, TTF_STYLE_BOLD);

	gJoystick = SDL_JoystickOpen(0);

	//Set screen resolution and check for errors
	PDL_Err err = PDL_GetScreenMetrics(&screenMetrics);
	//screenMetrics.verticalPixels = 400;
#if WIN32
	if(err == PDL_INVALIDINPUT)
		return -1;
	if(err == PDL_EOTHER)
	    screen = SDL_SetVideoMode(320, 480, 32, SDL_SWSURFACE);
	else
		screen = SDL_SetVideoMode(screenMetrics.horizontalPixels, screenMetrics.verticalPixels, 24, SDL_SWSURFACE);
#else
	// Tell it to use OpenGL version 1.0
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 1);
	//SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1);

	// Set the video mode to full screen
	Surface = SDL_SetVideoMode(screenMetrics.horizontalPixels, screenMetrics.verticalPixels, 0, SDL_OPENGL);

	Render = CreateSurface(0, 512, 512);
	screen = Render;

	// setup openGL
	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
	glViewport( 0, 0, screenMetrics.horizontalPixels, screenMetrics.verticalPixels );
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrthof(0, screenMetrics.horizontalPixels, screenMetrics.verticalPixels, 0, -1, 1);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

	glEnable( GL_TEXTURE_2D );
	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
	glDisable(GL_DEPTH_TEST);

	glGenTextures(1, &texture);
	glBindTexture(GL_TEXTURE_2D, texture);

#endif

	// Set initial positions
	x = (screenMetrics.horizontalPixels - 20) / 2;
	y = (screenMetrics.verticalPixels - 20) / 2;

	//The Event processing loop
	do {
		//Loop through all of the current events
		while (SDL_PollEvent(&sdlEvent)) {
			if (sdlEvent.type == SDL_KEYDOWN) {
				//Read the actual key that is down
				switch(sdlEvent.key.keysym.sym) {

					//Handle the escape key by exiting the program
					case SDLK_ESCAPE:
						sdlEvent.type = SDL_QUIT;
						break;

					default: break;
				}
			} else if (sdlEvent.type == SDL_JOYAXISMOTION) {
				if (bInitialUpdate) {
					double val = sdlEvent.jaxis.value / 32768.0;
					if (sdlEvent.jaxis.axis == 0) {
						initial_x = val;
					} else if (sdlEvent.jaxis.axis == 1) {
						initial_y = val;
					}
					if ((initial_x != 0.0) && (initial_y != 0.0)) {
						bInitialUpdate = false;
					}
				} else {
					double val = sdlEvent.jaxis.value / 32768.0;
					if (sdlEvent.jaxis.axis == 0) {
						val -= initial_x;
						a_x += val * val * val;
					} else if (sdlEvent.jaxis.axis == 1) {
						val -= initial_y;
						a_y += val * val * val;
					}
				}
			}
		}

		v_x += a_x;
		v_y += a_y;
		x += v_x;
		y += v_y;

#define ABSORPTION 0.5
		if (x < 0) {
			x = 0;
			v_x = -v_x * ABSORPTION;
			a_x = 0;
			Mix_PlayChannel(-1, explosion_sound, 0);
		}
		if (x > (screenMetrics.horizontalPixels-20)) {
			x = screenMetrics.horizontalPixels-20;
			v_x = -v_x * ABSORPTION;
			a_x = 0;
			Mix_PlayChannel(-1, explosion_sound, 0);
		}
		if (y < 0) {
			y = 0;
			v_y = -v_y * ABSORPTION;
			a_y = 0;
			Mix_PlayChannel(-1, explosion_sound, 0);
		}
		if (y > (screenMetrics.verticalPixels-20)) {
			y = screenMetrics.verticalPixels-20;
			v_y = -v_y * ABSORPTION;
			a_y = 0;
			Mix_PlayChannel(-1, explosion_sound, 0);
		}

		DrawScreen();
		UpdateDisplay(screen);

		//Don't be a cpu hog
		SDL_Delay(1);
	} while (sdlEvent.type != SDL_QUIT);

	if (explosion_sound)
		Mix_FreeChunk(explosion_sound);

	Mix_CloseAudio ();
	Mix_Quit();

	TTF_Quit();
    PDL_Quit();
    SDL_Quit();

    return 0;
}$

Feel free to use it to convert your own app and don’t forget to download: Mandel, Crimson Fields and Prankster from the AppCatalog for free.

Here is the project for you to download:

Download: simple simple (2,3 MiB, 1.231 hits)