example_1.c

/*
   example_1.c
     - demonstrates loading APIs
     - demonstrates hot reloading
*/

/*
Index of this file:
// [SECTION] includes
// [SECTION] structs
// [SECTION] apis
// [SECTION] pl_app_load
// [SECTION] pl_app_shutdown
// [SECTION] pl_app_resize
// [SECTION] pl_app_update
*/

//-----------------------------------------------------------------------------
// [SECTION] includes
//-----------------------------------------------------------------------------

#include <stdlib.h> // malloc, free
#include <stdio.h>
#include <string.h> // memset
#include "pl.h"
#include "pl_window_ext.h"

//-----------------------------------------------------------------------------
// [SECTION] structs
//-----------------------------------------------------------------------------

typedef struct _plAppData
{
    plWindow* ptWindow;
} plAppData;

//-----------------------------------------------------------------------------
// [SECTION] apis
//-----------------------------------------------------------------------------

const plIOI*     gptIO      = NULL;
const plWindowI* gptWindows = NULL;

//-----------------------------------------------------------------------------
// [SECTION] pl_app_load
//-----------------------------------------------------------------------------

PL_EXPORT void*
pl_app_load(plApiRegistryI* ptApiRegistry, plAppData* ptAppData)
{
    // NOTE: on first load, "pAppData" will be NULL but on reloads
    //       it will be the value returned from this function

    // retrieve the data registry API, this is the API used for sharing data
    // between extensions & the runtime
    const plDataRegistryI* ptDataRegistry = pl_get_api_latest(ptApiRegistry, plDataRegistryI);

    // load required apis
    gptIO      = pl_get_api_latest(ptApiRegistry, plIOI);
    gptWindows = pl_get_api_latest(ptApiRegistry, plWindowI);
    
    // if "ptAppData" is a valid pointer, then this function is being called
    // during a hot reload.
    if(ptAppData)
    {
        printf("Hot reload!\n");

        // return the same memory again
        return ptAppData;
    }

    // this path is taken only during first load, so we
    // allocate app memory here
    ptAppData = malloc(sizeof(plAppData));
    memset(ptAppData, 0, sizeof(plAppData));

    // use window API to create a window
    plWindowDesc tWindowDesc = {
        .pcTitle = "Example 1",
        .iXPos   = 200,
        .iYPos   = 200,
        .uWidth  = 600,
        .uHeight = 600,
    };
    gptWindows->create_window(tWindowDesc, &ptAppData->ptWindow);

    // return app memory
    return ptAppData;
}

//-----------------------------------------------------------------------------
// [SECTION] pl_app_shutdown
//-----------------------------------------------------------------------------

PL_EXPORT void
pl_app_shutdown(plAppData* ptAppData)
{
    // perform any cleanup here
    gptWindows->destroy_window(ptAppData->ptWindow);
    
    // free app memory
    free(ptAppData);
}

//-----------------------------------------------------------------------------
// [SECTION] pl_app_resize
//-----------------------------------------------------------------------------

PL_EXPORT void
pl_app_resize(plAppData* ptAppData)
{
    // perform any operations required during a window resize
    plIO* ptIO = gptIO->get_io();
    printf("resize to %d, %d\n", (int)ptIO->tMainViewportSize.x, (int)ptIO->tMainViewportSize.y);
}

//-----------------------------------------------------------------------------
// [SECTION] pl_app_update
//-----------------------------------------------------------------------------

PL_EXPORT void
pl_app_update(plAppData* ptAppData)
{

    gptIO->new_frame(); // must be called once at the beginning of a frame

    // check for key press
    if(gptIO->is_key_pressed(PL_KEY_P, true))
    {
        printf("P key pressed!\n");
    }

}