ELEMENT_MOVING_IMAGE

ELEMENT_MOVING_IMAGE, like ELEMENT_SLIDER, is used to move an image around on a gauge with two degrees of freedom. The difference is that ELEMENT_MOVING_IMAGE includes a mask, which does not move, and is used to hide parts of the image. In Flight Simulator 98, the whiskey compasses are drawn using ELEMENT_MOVING_IMAGE.

typedef struct ELEMENT_MOVING_IMAGE

{

HEADER;

MODULE_VARsource_var_x;

PMODULE_VAR_CBsource_var_x_cb;

FLOAT64min_x;

FLOAT64max_x;

PFN_FLOAT64lag_x;

MODULE_VARsource_var_y;

PMODULE_VAR_CBsource_var_y_cb;

FLOAT64min_y;

FLOAT64max_y;

PFN_FLOAT64lag_y;

FLOAT64scale_x;

FLOAT64scale_y;

FLOAT64offset_x;

FLOAT64offset_y;

PIXPOINTsave_position;

IMAGE_SETimage_data;

IMAGE_SETlocal_mask_data;

PIMAGEmask_data;

PIMAGEsave_buffer;

} ELEMENT_MOVING_IMAGE, *PELEMENT_MOVING_IMAGE, **PPELEMENT_MOVING_IMAGE;

ELEMENT_MOVING_IMAGE uses the following members:

Member	Description
HEADER	Discussed in detail in the topic Using Drawing Elements.
source_var_x	Token value used to calculate the slider's movement along the X axis.
source_var_x_cb	Callback function use for source_var_x.
min_x	Minimum value of source_var_x.
max_x	Maximum value of source_var_x.
lag_x	Do not use.
source_var_y	Token value used to calculate the slider’s movement along the Y axis.
source_var_y_cb	Callback function used for source_var_y.
min_y	Minimum value of source_var_y.
max_y	Maximum value of source_var_y.
lag_y	Do not use.
scale_x	Used internally by the Panel system; do not use. Must be set to 0.
scale_y	Used internally by the Panel system; do not use. Must be set to 0.
offset_x	Used internally by the Panel system; do not use. Must be set to 0.
offset_y	Used internally by the Panel system; do not use. Must be set to 0.
save_position	Used internally by the Panel system; do not use. Must be set to 0.
image_data	Used internally by the Panel system; do not use. Must be set to 0.
local_mask_data	Used internally by the Panel system; do not use. Must be set to 0.
mask_data	Used internally by the Panel system; do not use. Must be set to 0.
save_buffer	Used internally by the Panel system; do not use. Must be set to 0.

When the gauge is loading, the resource_id member specifies the image to use as the moving image. The resource_id + 3 specifies the mask image.

The mask is placed on the gauge using the position member. The moving image moves in reference to where the mask is placed. The image is moved in X and Y directions based on the source_var_x and source_var_y values. Looking at source_var_x, the image is placed so the image’s and mask’s left sides are aligned when source_var_x is equal to min_x. Similarly, the image’s and mask’s right sides are aligned when source_var_x is equal to max_x. Looking at source_var_y, the image is placed so the image’s and mask’s top sides are aligned when source_var_y is equal to min_y. Similarly, the image’s and mask’s bottom sides are aligned when source_var_y is equal to max_y.