g13-01.cpp

游戏开发数据结构Data Structures for Game Programmers

// ============================================================================
// G13-01.cpp
// Storing Resources Using Binary Search Trees
// ============================================================================
#include "SDLGUI.h"
#include "BinarySearchTree.h"
#include <stdlib.h>
#include <string.h>


// ============================================================================
//  Global Constants
// ============================================================================
const char PROGRAM_NAME[]   = "Game Demo 13-01: Resource Demo Revisited";
const int WIDTH             = 800;
const int HEIGHT            = 600;
const int ITEMS             = 32;
const int ARIAL             = 0;


// ============================================================================
//  Classes
// ============================================================================
class Resource
{
public:
    char m_string[64];
    SDL_Surface* m_surface;
};


// ============================================================================
//  Resource Compare'er
// ============================================================================
int ResourceCompare( Resource p_left, Resource p_right )
{
    return strcmp( p_left.m_string, p_right.m_string );
}


// ============================================================================
//  Global Variables
// ============================================================================
SDLGUI* g_gui;

// The Resource hash table:
BinarySearchTree< Resource > g_tree( ResourceCompare );

// the name of the current resource
char g_name[16] = "";

SDL_Surface* g_resource = 0;


// ============================================================================
//  Functions
// ============================================================================
void Find()
{
    // create a resource with the contents of the textbox
    Resource res;
    strcpy( res.m_string, g_name );

    BinaryTree<Resource>* node = 0;

    // search for the resource
    node = g_tree.Find( res );

    if( node != 0 )
        g_resource = node->m_data.m_surface;
    else
        g_resource = 0;
}


int main( int argc, char* argv[] )
{
    // declare coordinates.
    int x, y;

    // declare event holder
    SDL_Event event;

    // set our at exit function
    atexit( SDL_Quit );

    //initialize systems
    SDL_Init( SDL_INIT_VIDEO | SDL_INIT_TIMER );
    TTF_Init();

    SDL_EnableUNICODE( true );

    // create the GUI and set the caption.
    g_gui = new SDLGUI( WIDTH, HEIGHT, ITEMS, WHITE );
    SDL_WM_SetCaption( PROGRAM_NAME, 0); 
    g_gui->SetFont( "arial.ttf", ARIAL, 20, TTF_STYLE_NORMAL );


    Resource res;

    // add the resources to the tree.
    res.m_surface = SDL_LoadBMP( "sky.bmp" );
    strcpy( res.m_string, "sky" );
    g_tree.Insert( res );

    res.m_surface = SDL_LoadBMP( "water.bmp" );
    strcpy( res.m_string, "water" );
    g_tree.Insert( res );

    res.m_surface = SDL_LoadBMP( "fire.bmp" );
    strcpy( res.m_string, "fire" );
    g_tree.Insert( res );

    res.m_surface = SDL_LoadBMP( "water2.bmp" );
    strcpy( res.m_string, "water2" );
    g_tree.Insert( res );

    res.m_surface = SDL_LoadBMP( "snow.bmp" );
    strcpy( res.m_string, "snow" );
    g_tree.Insert( res );

    res.m_surface = SDL_LoadBMP( "vortex.bmp" );
    strcpy( res.m_string, "vortex" );
    g_tree.Insert( res );

    res.m_surface = SDL_LoadBMP( "stone.bmp" );
    strcpy( res.m_string, "stone" );
    g_tree.Insert( res );

    // clear the resource pointer.
    g_resource = 0;


    // add a text box, and set the focus.
    g_gui->AddTextBox( 0, 0, 128, TTF_FontHeight( g_gui->GetFont(ARIAL)),
                       g_name, 15, ARIAL, BLACK, WHITE, true, Find );
    g_gui->SetFocus( 0 );



    // main message loop.
    while( 1 )
    {
        //look for an event
        if( SDL_PollEvent( &event ) )
        {
            //an event was found
            if( event.type == SDL_QUIT ) 
                break;
            if( event.type == SDL_MOUSEBUTTONDOWN ) 
            {
                // get the mouse state.
                SDL_GetMouseState( &x, &y );

                // tell the GUI that a button has been pressed
                g_gui->MouseDown( x, y );
            }
            if( event.type == SDL_MOUSEBUTTONUP ) 
            {
                // get the mouse state.
                SDL_GetMouseState( &x, &y );

                // tell the GUI that a button has been released
                g_gui->MouseUp( x, y );
            }
            if( event.type == SDL_KEYDOWN )
            {
                // a key was pressed.
                if( event.key.keysym.sym == SDLK_ESCAPE )
                {
                    // if ESC was pressed, quit the program.
                    SDL_Event quit;
                    quit.type = SDL_QUIT;
                    SDL_PushEvent( &quit );
                }


                // tell the GUI that a key was pressed.
                g_gui->KeyDown( event.key.keysym.sym,
                                event.key.keysym.mod,
                                event.key.keysym.unicode );
            }
        }   // end event loop.


        // tell the GUI to redraw itself
        g_gui->Draw();

        if( g_resource != 0 )
            g_gui->Blit( g_resource, 188, 44 );

        // tell the GUI to update itself
        g_gui->Update();

    }
  
    // done
    return 0;
}