Graphics/Backgrounds/rotation/source/main.cpp

#include <nds.h>

#include <nds/arm9/console.h> //basic print funcionality
#include <nds/arm9/trig_lut.h>
#include <stdio.h>


// make file automaticaly makes a header file for access
// to the binary data in any file ending in .bin that is in
// the data folder.  It also links in that data to your project

#include "drunkenlogo_bin.h"
#include "palette_bin.h"


int main(void) {

    videoSetMode(MODE_5_2D );

    vramSetBankA(VRAM_A_MAIN_BG);

    consoleDemoInit();


    int bg3 = bgInit(3, BgType_Bmp8, BgSize_B8_256x256, 0,0);


    dmaCopy(drunkenlogo_bin, bgGetGfxPtr(bg3), 256*256);
    dmaCopy(palette_bin, BG_PALETTE, 256*2);

    s16 angle = 0;

    // the screen origin is at the rotation center...so scroll to the rotation
    // center + a small 32 pixle offset so our image is centered
    s16 scrollX = 128;
    s16 scrollY = 128 ;

    //scale is fixed point
    s16 scaleX = 1 << 8;
    s16 scaleY = 1 << 8;

    //this is the screen pixel that the image will rotate about
    s16 rcX = 128;
    s16 rcY = 96;

    while(1) {
        // Print status

        iprintf("\n\n\tHello DS devers\n");
        iprintf("\twww.drunkencoders.com\n");
        iprintf("\tBG Rotation demo\n");

        iprintf("Angle %3d(actual) %3d(degrees)\n", angle, (angle * 360) / (1<<15));
        iprintf("Scroll  X: %4d Y: %4d\n", scrollX, scrollY);
        iprintf("Rot center X: %4d Y: %4d\n", rcX, rcY);
        iprintf("Scale X: %4d Y: %4d\n", scaleX, scaleY);

        scanKeys();
        u32 keys = keysHeld();

        if( keys & KEY_L ) angle+=20;
        if( keys & KEY_R ) angle-=20;
        if( keys & KEY_LEFT ) scrollX++;
        if( keys & KEY_RIGHT ) scrollX--;
        if( keys & KEY_UP ) scrollY++;
        if( keys & KEY_DOWN ) scrollY--;
        if( keys & KEY_A ) scaleX++;
        if( keys & KEY_B ) scaleX--;
        if( keys & KEY_START ) rcX ++;
        if( keys & KEY_SELECT ) rcY++;
        if( keys & KEY_X ) scaleY++;
        if( keys & KEY_Y ) scaleY--;


        swiWaitForVBlank();

        bgSetCenter(bg3, rcX, rcY);
        bgSetRotateScale(bg3, angle, scaleX, scaleY);
        bgSetScroll(bg3, scrollX, scrollY);
        bgUpdate();

        // clear the console screen (ansi escape sequence)
        iprintf("\x1b[2J");



    }
    return 0;
}