Function CameraWorldToScreen

engine/render/src/render/camera.cpp:292–343

    }

    Result CameraWorldToScreen(HRenderContext render_context, HRenderCamera camera_handle, const dmVMath::Vector3& world, dmVMath::Vector3* out_screen)
    {
        RenderCamera* camera = render_context->m_RenderCameras.Get(camera_handle);

        // Project world to clip space
        dmVMath::Vector4 world4(world.getX(), world.getY(), world.getZ(), 1.0f);
        dmVMath::Vector4 clip = camera->m_ViewProjection * world4;
        float w = clip.getW();
        if (w > -EPS && w < EPS)
        {
            return RESULT_INVALID_PARAMETER;
        }
        float inv_w = 1.0f / w;
        float x_ndc = clip.getX() * inv_w;
        float y_ndc = clip.getY() * inv_w;

        // Window size
        dmGraphics::HContext gc = GetGraphicsContext(render_context);
        float win_w = (float) dmGraphics::GetWindowWidth(gc);
        float win_h = (float) dmGraphics::GetWindowHeight(gc);
        if (win_w <= 0.0f)
        {
            win_w = 1.0f;
        }
        if (win_h <= 0.0f)
        {
            win_h = 1.0f;
        }

        // Viewport mapping (Normalized Device Coordinates -> screen pixels)
        const dmVMath::Vector4& vp = camera->m_Data.m_Viewport;
        float vx = vp.getX() * win_w;
        float vy = vp.getY() * win_h;
        float vw = vp.getZ() * win_w;
        float vh = vp.getW() * win_h;
        if (vw <= 0.0f || vh <= 0.0f)
        {
            vx = 0.0f; vy = 0.0f; vw = win_w; vh = win_h;
        }

        float sx = vx + (x_ndc + 1.0f) * 0.5f * vw;
        float sy = vy + (y_ndc + 1.0f) * 0.5f * vh;

        // View depth along camera forward
        dmVMath::Vector3 forward = dmVMath::Rotate(camera->m_LastRotation, dmVMath::Vector3(0.0f, 0.0f, -1.0f));
        forward = dmVMath::Normalize(forward);
        dmVMath::Point3 world_p(world.getX(), world.getY(), world.getZ());
        float z_view = dmVMath::Dot(world_p - camera->m_LastPosition, forward);

        *out_screen = dmVMath::Vector3(sx, sy, z_view);
        return RESULT_OK;
    }

    // render_private.h
    RenderCamera* GetRenderCameraByUrl(HRenderContext render_context, const dmMessage::URL& camera_url)