Background Script (Scrolling)

let bSpell = false;

@Initialize {
    SetCameraElevationAngle(15);
    SetCameraAzimuthAngle(-90);

    SetCameraPerspectiveClip(0, 4000);

    TNormalBackground();
    TSpellBackground();
}

@MainLoop {
    let objScene = GetEnemyBossSceneObjectID();
    if(objScene != ID_INVALID && ObjEnemyBossScene_GetInfo(objScene, INFO_IS_SPELL)) {
        bSpell = true;
    } else {
        bSpell = false;
    }

    yield;
}


task TNormalBackground() {
    let frameInvisible = 0;
    let cameracount = 0;
    let scrollspeed = 8;
    let walldistance = 256; // Distance from path

    let path1 = GetCurrentScriptDirectory ~ "img/u3l30sampleB1.png";
    let path2 = GetCurrentScriptDirectory ~ "img/u3l30sampleB2.png";

    let obj1 = ObjPrim_Create(OBJ_SPRITE_3D); // Flooring
    ObjRender_SetBlendType(obj1, BLEND_ALPHA);
    Obj_SetRenderPriority(obj1, 0.21);
    ObjPrim_SetTexture(obj1, path1);
    ObjSprite3D_SetDestRect(obj1, -1024, -1024 * 4, 1024, 1024 * 4); // Output ratio is 1x4
    ObjRender_SetAngleX(obj1, 90);

    let obj2 = ObjPrim_Create(OBJ_SPRITE_3D); // Path
    ObjRender_SetBlendType(obj2, BLEND_ALPHA);
    Obj_SetRenderPriority(obj2, 0.21);
    ObjPrim_SetTexture(obj2, path2);
    ObjSprite3D_SetDestRect(obj2, -128, -1024 * 4, 128, 1024 * 4); // Output ratio is 1x32
    ObjRender_SetAngleX(obj2, 90);

    ascent(i in 0..5) {
        CreateWall(-walldistance, -75, 2, 512 + i*512);
        CreateWall(walldistance, 75, 2, 512 + i*512);
        CreateWall(-walldistance, 75, 2, 256 + i*512);
        CreateWall(walldistance, -75, 2, 256 + i*512);
    }

    loop {
        if(bSpell) {
            frameInvisible++;
            if(frameInvisible >= 60) {
                Obj_SetVisible(obj1, false);
                Obj_SetVisible(obj2, false);
            }
        } else {
            frameInvisible = 0;
            Obj_SetVisible(obj1, true);
            Obj_SetVisible(obj2, true);
        }

        if (cameracount % 512 == 0) {
            CreateWall(-walldistance, -75, 2, 0);
            CreateWall(walldistance, 75, 2, 0);
        }
        if (cameracount % 512 == 256) {
            CreateWall(-walldistance, 75, 2, 0);
            CreateWall(walldistance, -75, 2, 0);
        }

        SetCameraAzimuthAngle(-90 + 20*sin(cameracount*0.5));

        // Scroll by setting the source rects
        ObjSprite3D_SetSourceRect(obj1, 0, 0 + cameracount*scrollspeed, 1024*8, 1024 * 32 + cameracount*scrollspeed);
        ObjSprite3D_SetSourceRect(obj2, 0, 0 + cameracount*scrollspeed, 1024  , 1024 * 32 + cameracount*scrollspeed);

        cameracount++;
        yield;
    }
}

task CreateWall(x, angle, movespeed, objcount) {
    let path3 = GetCurrentScriptDirectory ~ "img/u3l30sampleB3.png";

    let totallength = GetTotalWallLength(512, angle);

    let obj3 = ObjPrim_Create(OBJ_SPRITE_3D); // Wall
    ObjRender_SetBlendType(obj3, BLEND_ALPHA);
    Obj_SetRenderPriority(obj3, 0.21);
    ObjPrim_SetTexture(obj3, path3);
    ObjSprite3D_SetSourceRect(obj3, 0, 0, 1024*2, 1024);
    ObjSprite3D_SetDestRect(obj3, -totallength/2, 0, totallength/2, totallength/2);

    ObjRender_SetX(obj3, x);
    ObjRender_SetAngleY(obj3, angle);
    ObjRender_SetZWrite(obj3, true);

    loop {
        if(bSpell) {
            Obj_SetVisible(obj3, false);
        } else {
            Obj_SetVisible(obj3, true);
        }

        ObjRender_SetZ(obj3, 4096 - objcount*movespeed);

        if (objcount > 4096) {
            Obj_Delete(obj3);
        }

        objcount += 1;
        yield;
    }
}

// Given the length of a line, returns the length if that segment were rotated at the specified angle and extended to meet the bounding square
function GetTotalWallLength(seglen, angle) {
    return seglen/max(absolute(sin(angle)), absolute(cos(angle)));
}

task TSpellBackground {
    let alpha = 0;
    let frame = 0;
    loop {
        if(bSpell) {
            alpha += 4;
        } else {
            alpha = 0;
        }

        frame++;
        yield;
    }

}