void main()
{
//extract just the x and y values from the current fragmentCoordinates. normally xyzw
vec2 pos = vec2(gl_FragCoord.x, gl_FragCoord.y);
//get sample color from texture
vec4 topColor = texture(top, pos);
vec4 bottomColor = texture(bottom, pos);
vec4 maskColor = texture(mask, pos);
//polarize the masking value
float maskValue = polarize(maskColor.r);
vec3 alphaTop = maskValue * topColor.rgb;
vec3 alphaBottom = (1.0 - maskValue) * bottomColor.rgb;
outputColor = vec4((alphaTop + alphaBottom), 1.0);
}
static void
run (const gchar *name,
gint nparams,
const GimpParam *param,
gint *nreturn_vals,
GimpParam **return_vals)
{
static GimpParam values[1];
GimpDrawable *drawable;
GimpPDBStatusType status;
GimpRunMode run_mode;
gdouble xhsiz, yhsiz;
GimpRGB background;
status = GIMP_PDB_SUCCESS;
run_mode = param[0].data.d_int32;
values[0].type = GIMP_PDB_STATUS;
values[0].data.d_status = status;
*nreturn_vals = 1;
*return_vals = values;
INIT_I18N ();
/* Get the active drawable info */
drawable = gimp_drawable_get (param[2].data.d_drawable);
img_width = gimp_drawable_width (drawable->drawable_id);
img_height = gimp_drawable_height (drawable->drawable_id);
img_has_alpha = gimp_drawable_has_alpha (drawable->drawable_id);
gimp_drawable_mask_bounds (drawable->drawable_id,
&sel_x1, &sel_y1, &sel_x2, &sel_y2);
/* Calculate scaling parameters */
sel_width = sel_x2 - sel_x1;
sel_height = sel_y2 - sel_y1;
cen_x = (double) (sel_x1 + sel_x2 - 1) / 2.0;
cen_y = (double) (sel_y1 + sel_y2 - 1) / 2.0;
xhsiz = (double) (sel_width - 1) / 2.0;
yhsiz = (double) (sel_height - 1) / 2.0;
if (xhsiz < yhsiz)
{
scale_x = yhsiz / xhsiz;
scale_y = 1.0;
}
else if (xhsiz > yhsiz)
{
scale_x = 1.0;
scale_y = xhsiz / yhsiz;
}
else
{
scale_x = 1.0;
scale_y = 1.0;
}
/* Get background color */
gimp_context_get_background (&background);
gimp_rgb_set_alpha (&background, 0.0);
gimp_drawable_get_color_uchar (drawable->drawable_id, &background,
back_color);
/* See how we will run */
switch (run_mode)
{
case GIMP_RUN_INTERACTIVE:
/* Possibly retrieve data */
gimp_get_data (PLUG_IN_PROC, &pcvals);
/* Get information from the dialog */
if (! polarize_dialog (drawable))
return;
break;
case GIMP_RUN_NONINTERACTIVE:
/* Make sure all the arguments are present */
if (nparams != 8)
{
status = GIMP_PDB_CALLING_ERROR;
}
else
{
pcvals.circle = param[3].data.d_float;
pcvals.angle = param[4].data.d_float;
pcvals.backwards = param[5].data.d_int32;
pcvals.inverse = param[6].data.d_int32;
pcvals.polrec = param[7].data.d_int32;
}
break;
case GIMP_RUN_WITH_LAST_VALS:
/* Possibly retrieve data */
gimp_get_data (PLUG_IN_PROC, &pcvals);
break;
default:
break;
}
/* Distort the image */
if ((status == GIMP_PDB_SUCCESS) &&
(gimp_drawable_is_rgb (drawable->drawable_id) ||
gimp_drawable_is_gray (drawable->drawable_id)))
{
/* Set the tile cache size */
gimp_tile_cache_ntiles (2 * (drawable->width + gimp_tile_width() - 1) /
gimp_tile_width ());
/* Run! */
polarize (drawable);
/* If run mode is interactive, flush displays */
if (run_mode != GIMP_RUN_NONINTERACTIVE)
gimp_displays_flush ();
/* Store data */
if (run_mode == GIMP_RUN_INTERACTIVE)
gimp_set_data (PLUG_IN_PROC, &pcvals, sizeof (polarize_vals_t));
}
else if (status == GIMP_PDB_SUCCESS)
status = GIMP_PDB_EXECUTION_ERROR;
values[0].data.d_status = status;
gimp_drawable_detach (drawable);
}
bool isInWorld(CIwFVec2 position, float innerRad, float outerRad) {
polarize(position);
return position.x > innerRad && position.x < outerRad;
}