/**
 * @file lv_ctr_disp.c
 *
 */

#if 1

/*********************
 *      INCLUDES
 *********************/
#include "lv_ctr_disp.h"
#include <stdbool.h>
#include <3ds.h>
#include <citro3d.h>
#include <citro2d.h>

/*********************
 *      DEFINES
 *********************/
#define BOTTOM_DISP_HOR_RES    320
#define BOTTOM_DISP_VER_RES    240
#define BOTTOM_TEX_HOR_RES     512
#define BOTTOM_TEX_VER_RES     256

#define BYTE_PER_PIXEL (LV_COLOR_FORMAT_GET_SIZE(LV_COLOR_FORMAT_ARGB8888))

/**********************
 *      TYPEDEFS
 **********************/

/**********************
 *  STATIC PROTOTYPES
 **********************/
static void disp_init(void);

static void disp_flush(lv_display_t * disp, const lv_area_t * area, uint8_t * px_map);

/* Calculate nearest power of 2 for a given size */
__attribute__ ((const)) static inline u32 tex_pot(u32 x) {
        if (x < 32) return 32;
        return 1 << (32 - __builtin_clz(x - 1));
}

/**********************
 *  STATIC VARIABLES
 **********************/

C3D_RenderTarget *bottom_screen;
C3D_Tex tex;
Tex3DS_SubTexture subt3x;

/**********************
 *      MACROS
 **********************/

/**********************
 *   GLOBAL FUNCTIONS
 **********************/

void lv_ctr_disp_init(void)
{
    /*-------------------------
     * Initialize your display
     * -----------------------*/
    disp_init();

    /*------------------------------------
     * Create a display and set a flush_cb
     * -----------------------------------*/
    lv_display_t * bottom_disp = lv_display_create(BOTTOM_DISP_HOR_RES, BOTTOM_DISP_VER_RES);
    lv_display_set_flush_cb(bottom_disp, disp_flush);

    /* Two buffers for double buffering. */
#define BOTTOM_TEX_STRIDE (BOTTOM_TEX_HOR_RES * BYTE_PER_PIXEL)
    LV_ATTRIBUTE_MEM_ALIGN static uint8_t buf_1[BOTTOM_TEX_STRIDE * BOTTOM_DISP_VER_RES];
    LV_ATTRIBUTE_MEM_ALIGN static uint8_t buf_2[BOTTOM_TEX_STRIDE * BOTTOM_DISP_VER_RES];
    lv_display_set_buffers_with_stride(bottom_disp, buf_1, buf_2, sizeof(buf_1), BOTTOM_TEX_STRIDE, LV_DISPLAY_RENDER_MODE_FULL);

}

/**********************
 *   STATIC FUNCTIONS
 **********************/

/*Initialize your display and the required peripherals.*/
static void disp_init(void)
{
    gfxInitDefault();

    ptmuInit();

    C3D_Init(C3D_DEFAULT_CMDBUF_SIZE);
    C2D_Init(C2D_DEFAULT_MAX_OBJECTS);
    C2D_Prepare();
    bottom_screen = C2D_CreateScreenTarget(GFX_BOTTOM, GFX_LEFT);

    if(0 == C3D_TexInit(&tex, BOTTOM_TEX_HOR_RES, BOTTOM_TEX_VER_RES, GPU_RGB8)) puts("Could not create main texture.");
    memset(tex.data, 0, tex.size);
    tex.border = 0xFFFFFFFF;
    C3D_TexSetWrap(&tex, GPU_CLAMP_TO_BORDER, GPU_CLAMP_TO_BORDER);

    subt3x.width = BOTTOM_DISP_HOR_RES;
    subt3x.height = BOTTOM_DISP_VER_RES;
    subt3x.left = 0.0f;
    subt3x.top = 1.0f;
    subt3x.right = (BOTTOM_DISP_HOR_RES/(float)tex.width);
    subt3x.bottom = (1.0f - BOTTOM_DISP_VER_RES/(float)tex.height);

    C3D_TexSetFilter(&tex, GPU_NEAREST, GPU_NEAREST);
}

volatile bool disp_flush_enabled = true;

/* Enable updating the screen (the flushing process) when disp_flush() is called by LVGL
 */
void disp_enable_update(void)
{
    disp_flush_enabled = true;
}

/* Disable updating the screen (the flushing process) when disp_flush() is called by LVGL
 */
void disp_disable_update(void)
{
    disp_flush_enabled = false;
}

/*Flush the content of the internal buffer the specific area on the display.
 *`px_map` contains the rendered image as raw pixel map and it should be copied to `area` on the display.
 *You can use DMA or any hardware acceleration to do this operation in the background but
 *'lv_display_flush_ready()' has to be called when it's finished.*/
static void disp_flush(lv_display_t * disp_drv, const lv_area_t * area, uint8_t * px_map)
{
    if (lv_display_flush_is_last(disp_drv)) {
        GSPGPU_FlushDataCache(px_map, tex.width * tex.height * 4);

	u32 dim = GX_BUFFER_DIM(tex.width, tex.height);
	C3D_SyncDisplayTransfer((u32 *)px_map, dim, (u32*)tex.data, dim,
		(GX_TRANSFER_FLIP_VERT(0) | GX_TRANSFER_OUT_TILED(1) | GX_TRANSFER_RAW_COPY(0) |
		GX_TRANSFER_IN_FORMAT(GX_TRANSFER_FMT_RGBA8) | GX_TRANSFER_OUT_FORMAT(GX_TRANSFER_FMT_RGB8) |
		GX_TRANSFER_SCALING(GX_TRANSFER_SCALE_NO))
	);

	// start frame, clear targets
	C3D_FrameBegin(C3D_FRAME_SYNCDRAW);
	C2D_TargetClear(bottom_screen, C2D_Color32f(0, 0, 0, 1));

	C2D_SceneBegin(bottom_screen);

	C2D_Image img = { &tex, &subt3x };
	C2D_DrawImageAt(img, 0, 0, 0.6f, NULL, 1.0f, 1.0f);

        C3D_FrameEnd(0);
    }
    lv_display_flush_ready(disp_drv);
}

#else /*Enable this file at the top*/

/*This dummy typedef exists purely to silence -Wpedantic.*/
typedef int keep_pedantic_happy;
#endif