pipewire: Properly account for cursor hotspot

The cursor bitmap is centered on the hotspot, so not accounting
for it means PipeWire captures were positioning the cursor sprite
slightly off.

Properly account for the hotspot by subtracting it from the cursor
position.

Related: https://github.com/obsproject/obs-studio/issues/4766

plugins/linux-capture/pipewire.c

@@ -1234,9 +1234,11 @@ void obs_pipewire_video_render(obs_pipewire_data *obs_pw, gs_effect_t *effect)
 
 	if (obs_pw->cursor.visible && obs_pw->cursor.valid &&
 	    obs_pw->cursor.texture) {
+		float cursor_x = obs_pw->cursor.x - obs_pw->cursor.hotspot_x;
+		float cursor_y = obs_pw->cursor.y - obs_pw->cursor.hotspot_y;
+
 		gs_matrix_push();
-		gs_matrix_translate3f((float)obs_pw->cursor.x,
-				      (float)obs_pw->cursor.y, 0.0f);
+		gs_matrix_translate3f(cursor_x, cursor_y, 0.0f);
 
 		gs_effect_set_texture(image, obs_pw->cursor.texture);
 		gs_draw_sprite(obs_pw->texture, 0, obs_pw->cursor.width,