/*{
"CATEGORIES": [
"Masking",
"Geometry Adjustment"
],
"CREDIT": "",
"DESCRIPTION": "",
"INPUTS": [
{
"NAME": "inputImage",
"TYPE": "image"
},
{
"DEFAULT": [
0,
0
],
"LABEL": "Bottom left",
"MAX": [
1,
1
],
"MIN": [
0,
0
],
"NAME": "pt1",
"TYPE": "point2D"
},
{
"DEFAULT": [
1,
0
],
"LABEL": "Top left",
"MAX": [
1,
1
],
"MIN": [
0,
0
],
"NAME": "pt2",
"TYPE": "point2D"
},
{
"DEFAULT": [
1,
1
],
"LABEL": "Top right",
"MAX": [
1,
1
],
"MIN": [
0,
0
],
"NAME": "pt3",
"TYPE": "point2D"
},
{
"DEFAULT": [
0,
1
],
"LABEL": "Bottom right",
"MAX": [
1,
1
],
"MIN": [
0,
0
],
"NAME": "pt4",
"TYPE": "point2D"
},
{
"DEFAULT": 0,
"LABEL": "Invert Mask",
"NAME": "invertMask",
"TYPE": "bool"
},
{
"DEFAULT": 0,
"LABEL": "Apply Mask",
"LABELS": [
"Apply Mask",
"Set Alpha",
"Show Mask"
],
"NAME": "maskApplyMode",
"TYPE": "long",
"VALUES": [
0,
1,
2
]
}
],
"ISFVSN": "2"
}
*/
float sign(vec2 p1, vec2 p2, vec2 p3)
{
return (p1.x - p3.x) * (p2.y - p3.y) - (p2.x - p3.x) * (p1.y - p3.y);
}
bool PointInTriangle(vec2 pt, vec2 v1, vec2 v2, vec2 v3)
{
bool b1, b2, b3;
b1 = sign(pt, v1, v2) < 0.0;
b2 = sign(pt, v2, v3) < 0.0;
b3 = sign(pt, v3, v1) < 0.0;
return ((b1 == b2) && (b2 == b3));
}
void main() {
vec4 inputPixelColor = IMG_THIS_PIXEL(inputImage);
vec2 loc = isf_FragNormCoord;
bool drawPixel = false;
if ((PointInTriangle(loc,pt1,pt2,pt3))||(PointInTriangle(loc,pt1,pt4,pt3))) {
drawPixel = true;
}
if (invertMask)
drawPixel = !drawPixel;
if (maskApplyMode == 0) {
inputPixelColor = (drawPixel) ? inputPixelColor : vec4(0.0);
}
// in this mode only the alpha is changed; the rgb remains intact and may still be visible if another filter adjusts the alpha again
else if (maskApplyMode == 1) {
inputPixelColor.a = (drawPixel) ? inputPixelColor.a : 0.0;
}
else if (maskApplyMode == 2) {
inputPixelColor = (drawPixel) ? vec4(1.0) : vec4(0.0);
}
gl_FragColor = inputPixelColor;
}
