obs-filters: Reset cx/cy/mul/add crop vals in tick, not render

To first render the filter, the width/height values must be set, but
currently they're only set in the render function, which means that the
crop filter can never be rendered when the program first starts up.
This would cause the filter to fail to render at all under those
circumstances.

This patch moves the calculations from render to tick to ensure that
they're always called and the values are always set.

plugins/obs-filters/crop-filter.c

@@ -17,6 +17,9 @@ struct crop_filter_data {
 	uint32_t                       width;
 	uint32_t                       height;
 	bool                           absolute;
+
+	struct vec2                    mul_val;
+	struct vec2                    add_val;
 };
 
 static const char *crop_filter_get_name(void *unused)
@@ -175,21 +178,24 @@ static void calc_crop_dimensions(struct crop_filter_data *filter,
 	}
 }
 
-static void crop_filter_render(void *data, gs_effect_t *effect)
+static void crop_filter_tick(void *data, float seconds)
 {
 	struct crop_filter_data *filter = data;
-	struct vec2 mul_val;
-	struct vec2 add_val;
 
-	vec2_zero(&mul_val);
-	vec2_zero(&add_val);
-	calc_crop_dimensions(filter, &mul_val, &add_val);
+	vec2_zero(&filter->mul_val);
+	vec2_zero(&filter->add_val);
+	calc_crop_dimensions(filter, &filter->mul_val, &filter->add_val);
+}
+
+static void crop_filter_render(void *data, gs_effect_t *effect)
+{
+	struct crop_filter_data *filter = data;
 
 	obs_source_process_filter_begin(filter->context, GS_RGBA,
 			OBS_NO_DIRECT_RENDERING);
 
-	gs_effect_set_vec2(filter->param_mul, &mul_val);
-	gs_effect_set_vec2(filter->param_add, &add_val);
+	gs_effect_set_vec2(filter->param_mul, &filter->mul_val);
+	gs_effect_set_vec2(filter->param_add, &filter->add_val);
 
 	obs_source_process_filter_end(filter->context, filter->effect,
 			filter->width, filter->height);
@@ -219,6 +225,7 @@ struct obs_source_info crop_filter = {
 	.update                        = crop_filter_update,
 	.get_properties                = crop_filter_properties,
 	.get_defaults                  = crop_filter_defaults,
+	.video_tick                    = crop_filter_tick,
 	.video_render                  = crop_filter_render,
 	.get_width                     = crop_filter_width,
 	.get_height                    = crop_filter_height