Animating two spries independently with DirectX

[Meatpuppet]

Can someone help me?

I'm going through a DirectX book, this is the "on your own" part of the Drawing and Animating Sprites chapter.

Here is my code.

Sprite Draw and Animate Functions:

[cpp]
void Sprite_Draw_Frame(LPDIRECT3DTEXTURE9 texture, int destx, int desty, int framenum, int framew, int frameh, int columns)
{
D3DXVECTOR3 position((float)destx, (float)desty, 0);
D3DCOLOR white = D3DCOLOR_XRGB(255, 255, 255);

RECT rect;
rect.left = (framenum % columns) * framew;
rect.top = (framenum / columns) * frameh;
rect.right = rect.left + framew;
rect.bottom = rect.top + frameh;

spriteobj->Draw(texture, &rect, NULL, &position, white);

}

void Sprite_Animate(int &frame, int startframe, int endframe, int direction, int &starttime, int delay)
{
if((int)GetTickCount() > starttime + delay)
{
starttime = GetTickCount();

frame += direction;
if(frame > endframe) frame = startframe;
if(frame < startframe) frame = endframe;
}

}[/cpp]

Rendering function:

[cpp]void Game_Run(HWND window)
{
//make sure the Direct3D device is valid
if (!d3ddev) return;

//update input devices
DirectInput_Update();

//clear the scene
d3ddev->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, D3DCOLOR_XRGB(0,0,100), 1.0f, 0);

//start rendering
if (d3ddev->BeginScene())
{
spriteobj->Begin(D3DXSPRITE_ALPHABLEND);

Sprite_Animate(frame, 0, 29, 1, starttime, 30);
Sprite_Draw_Frame(explosion, 200, 200, frame, 128, 128, 6);

//stop rendering
spriteobj->End();
d3ddev->EndScene();
d3ddev->Present(NULL, NULL, NULL, NULL);

}[/cpp]
1. The Animate Sprite project in this chapter does show how animation works, but it's kind of a boring demo. Modify the program so that it generates more than one explosion sprite at a time.

I have successfully accomplished that.
[cpp] if (d3ddev->BeginScene())
{
spriteobj->Begin(D3DXSPRITE_ALPHABLEND);

Sprite_Animate(frame, 0, 29, 1, starttime, 30);
Sprite_Draw_Frame(explosion, 200, 200, frame, 128, 128, 6);
Sprite_Draw_Frame(explosion1, 500, 500, frame, 128, 128, 6);
//stop rendering
spriteobj->End();
d3ddev->EndScene();
d3ddev->Present(NULL, NULL, NULL, NULL);

}[/cpp]

It [I]does[/I] render two, but obviously at the same time, speed, and relative to each other. I want to know how to make two [I]separate[/I] sprites, which leads on to the next example:

2. Building on the previous example, now modify the project so that each explosion is animated at a random animation rate.

Can someone help me?

[pepin180]

starttime variable is being updated to the last time a frame was rendered, and the frame counter will increase only if starttime+delay time has passed. it means if you use two separated frame counters, you can make them grow at different speed just by changing their delay values. For example:

if (d3ddev->BeginScene())
{
    spriteobj->Begin(D3DXSPRITE_ALPHABLEND);
 
 
    Sprite_Animate(frame, 0, 29, 1, starttime, 30);
    Sprite_Animate(frame1, 0, 29, 1, starttime1, 10);

    Sprite_Draw_Frame(explosion, 200, 200, frame, 128, 128, 6);
    Sprite_Draw_Frame(explosion1, 500, 500, frame1, 128, 128, 6);
    //stop rendering
    spriteobj->End();
    d3ddev->EndScene();
    d3ddev->Present(NULL, NULL, NULL, NULL);
 
}

If you want, you can also increase the 'direction' value, so you'll skip some frames, making the animation go faster, but maybe bad looking.

[Meatpuppet]

[QUOTE=pepin180;37945738]starttime variable is being updated to the last time a frame was rendered, and the frame counter will increase only if starttime+delay time has passed. it means if you use two separated frame counters, you can make them grow at different speed just by changing their delay values. For example:

if (d3ddev->BeginScene())
{
    spriteobj->Begin(D3DXSPRITE_ALPHABLEND);
 
 
    Sprite_Animate(frame, 0, 29, 1, starttime, 30);
    Sprite_Animate(frame1, 0, 29, 1, starttime1, 10);

    Sprite_Draw_Frame(explosion, 200, 200, frame, 128, 128, 6);
    Sprite_Draw_Frame(explosion1, 500, 500, frame1, 128, 128, 6);
    //stop rendering
    spriteobj->End();
    d3ddev->EndScene();
    d3ddev->Present(NULL, NULL, NULL, NULL);
 
}

If you want, you can also increase the 'direction' value, so you'll skip some frames, making the animation go faster, but maybe bad looking.[/QUOTE]
I tried a method like that before (using those same variables even!) but I'll try your method. Thanks.

[editline]7th October 2012[/editline]

Haha, thanks a lot man! I think I was about to solve it, too, as I had, literally, those same variables used in your code. Much appreciated :)