Help with Rendering Images In-Game (WotLK 3.3.5a)

[Makkah]

Hello,

I'm currently working on adding image rendering to my in-game drawing API for WotLK 3.3.5a. The texture loads correctly and I'm able to confirm it's valid, but for some reason, the image isn't being drawn on screen.

I've gone through my projection and rendering code, but can't seem to figure out what’s going wrong. Any help or pointers would be greatly appreciated! 😄

Thanks in advance!

void Draw::DrawImageAtPosition(Vector3 worldPos, float size, LPDIRECT3DTEXTURE9 texture, LPDIRECT3DDEVICE9 dev)
{
    if (!dev) {
        printf("[DrawImage] Device is null.\n");
        return;
    }

    if (!texture) {
        printf("[DrawImage] Texture is null. Skipping image draw.\n");
        Draw::DrawBox(worldPos, size, D3DCOLOR_ARGB(255, 255, 0, 0), dev);
        return;
    }

    CameraInfo* cam = (CameraInfo*)Camera::GetActiveCamera();
    if (!cam) {
        printf("[DrawImage] No active camera.\n");
        Draw::DrawBox(worldPos, size, D3DCOLOR_ARGB(255, 255, 0, 0), dev);
        return;
    }

    // Build camera matrices
    D3DXMATRIX world, view, projection;
    D3DXMatrixIdentity(&world);

    D3DXVECTOR3 eye = cam->Position;
    D3DXVECTOR3 at = eye + Camera::Forward();
    D3DXVECTOR3 up(0, 0, 1);

    D3DXMatrixLookAtRH(&view, &eye, &at, &up);
    D3DXMatrixPerspectiveFovRH(&projection, cam->FieldOfView * 0.6f, cam->Aspect, cam->NearPlane, cam->FarPlane);

    // Project 3D world position to 2D screen
    D3DVIEWPORT9 viewport;
    dev->GetViewport(&viewport);

    D3DXVECTOR3 screenPos;
    D3DXVECTOR3 input(worldPos.X, worldPos.Y, worldPos.Z);

    if (!D3DXVec3Project(&screenPos, &input, &viewport, &projection, &view, &world)) {
        printf("[DrawImage] D3DXVec3Project failed.\n");
        Draw::DrawBox(worldPos, size, D3DCOLOR_ARGB(255, 255, 0, 0), dev);
        return;
    }

    if (screenPos.z < 0.0f || screenPos.z > 1.0f) {
        printf("[DrawImage] Projected Z out of view range: %.2f\n", screenPos.z);
        Draw::DrawBox(worldPos, size, D3DCOLOR_ARGB(255, 255, 0, 0), dev);
        return;
    }

    // Debug projection result
    printf("[DrawImage] Projected screen X=%.2f Y=%.2f Z=%.2f\n", screenPos.x, screenPos.y, screenPos.z);

    // Prepare screen-space quad
    float half = size / 2.0f;

    struct ScreenVertex {
        float x, y, z, rhw;
        float u, v;
    };

    ScreenVertex quad[4] = {
        { screenPos.x - half, screenPos.y - half, 0.0f, 1.0f, 0.0f, 0.0f },
        { screenPos.x + half, screenPos.y - half, 0.0f, 1.0f, 1.0f, 0.0f },
        { screenPos.x + half, screenPos.y + half, 0.0f, 1.0f, 1.0f, 1.0f },
        { screenPos.x - half, screenPos.y + half, 0.0f, 1.0f, 0.0f, 1.0f }
    };

    quad->rhw = 1.0f;

    // Set rendering state
    dev->SetTexture(0, texture);
    dev->SetFVF(D3DFVF_XYZRHW | D3DFVF_TEX1);
    dev->SetRenderState(D3DRS_ZENABLE, FALSE);
    dev->SetRenderState(D3DRS_ZWRITEENABLE, FALSE);
    dev->SetRenderState(D3DRS_ALPHABLENDENABLE, TRUE);
    dev->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA);
    dev->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA);
    dev->SetRenderState(D3DRS_CULLMODE, D3DCULL_NONE);


    HRESULT hr = dev->DrawPrimitiveUP(D3DPT_TRIANGLEFAN, 2, quad, sizeof(ScreenVertex));
    if (FAILED(hr)) {
        printf("[DrawImage] DrawPrimitiveUP failed (HRESULT: 0x%08X). Drawing fallback box.\n", hr);
        Draw::DrawBox(worldPos, size, D3DCOLOR_ARGB(255, 255, 0, 0), dev);
    }
    else {
        printf("[DrawImage] Image draw completed successfully.\n");
    }
}

[demerda10]

Can you give us more info about the "problem"?

First, do any of these printf return the error?

Try removing the "out of view" until you get it working.
Sometimes it would be drawing, but in incorrect position, but because of this, is isn't drawing at all.
And incorrect render is better than no render for debugging purposes.

Also, are you able to draw very simple shapes first? Like a circle or just a line.
Just so we can make sure there is nothing wrong with the projection mathematics or the camera values or render state.

[Makkah]

I have drawing lines, circle etc working there is nothing wrong with projection mathematics or camera values. but i am trying to put a image on unitpositions but it not showing the texture

[demerda10]

Mind sharing how you are loading the texture?
Even if it isn't null pointer, it can still fail (not draw) for other reasons texture related.

Also, have you tried using ID3DXSprite instead of drawing quads directly ?

[cowah]

Memory editing’s never easy, especially with older games like Would 3.3.5a. I ran into similar stuff messing with Null’s Brawl mods textures not showing up right or memory addresses being off. Usually just takes some patience and tweaking to figure out what’s going wrong.

[Makkah]

I was never able to figure it out, so i kinda gave up on adding my own textures,