## Asymptote and opacity – fig0110

Category: Asymptote,Examples 2D,OpacityPh. Ivaldi @ 2 h 54 min

 (Compiled with Asymptote version 1.87svn-r4652)
```
import edvenn_pi;

// SoftLight: Darkens or lightens the colors, depending on the source color value.
// If the source color is lighter than 0.5, the backdrop is lightened as if
// it were dodged; this is useful for adding highlights to a scene. If the
// source color is darker than 0.5, the backdrop is darkened as if it
// were burned in. The degree of lightening or darkening is proportional
// to the difference between the source color and 0.5; if it is
// equal to 0.5, the backdrop is unchanged. Painting with pure black or
// white produces a distinctly darker or lighter area but does not result
// in pure black or white. The effect is similar to shining a diffused
// spotlight on the backdrop.
string blend="SoftLight";

size(10cm,0);

path [] edvenn= EdVenn(4);
pen [] fillp= new pen[]{black, red, green, blue};
pen p=linewidth(1mm);

for (int i=0; i<4; ++i) {
fillp[i]=fillp[i]+opacity(.5,blend=blend);
filldraw(edvenn[i], fillpen=fillp[i], drawpen=linewidth((i+1)*mm/2));
}

shipout(bbox(2mm,invisible),"pdf");

```

Étiquettes :

## Asymptote and opacity – fig0120

Category: Asymptote,Examples 2D,OpacityPh. Ivaldi @ 3 h 54 min

 (Compiled with Asymptote version 1.87svn-r4652)
```
import edvenn_pi;

// Difference: Subtracts the darker of the two constituent colors from the lighter
// color:
// Painting with white inverts the backdrop color; painting with black
// produces no change.
string blend="Difference";

size(10cm,0);

path [] edvenn= EdVenn(4);
pen [] fillp= new pen[]{black, red, green, blue};
pen p=linewidth(1mm);

for (int i=0; i<4; ++i) {
fillp[i]=fillp[i]+opacity(.5,blend=blend);
filldraw(edvenn[i], fillpen=fillp[i], drawpen=linewidth((i+1)*mm/2));
}

shipout(bbox(2mm,invisible),"pdf");

```

Étiquettes :

## Asymptote and opacity – fig0130

Category: Asymptote,Examples 2D,OpacityPh. Ivaldi @ 4 h 54 min

 (Compiled with Asymptote version 1.87svn-r4652)
```
import edvenn_pi;

// Exclusion: Produces an effect similar to that of the Difference mode but lower
// in contrast. Painting with white inverts the backdrop color; painting
// with black produces no change.
string blend="Exclusion";

size(10cm,0);

path [] edvenn= EdVenn(4);
pen [] fillp= new pen[]{black, red, green, blue};
pen p=linewidth(1mm);

for (int i=0; i<4; ++i) {
fillp[i]=fillp[i]+opacity(.5,blend=blend);
filldraw(edvenn[i], fillpen=fillp[i], drawpen=linewidth((i+1)*mm/2));
}

shipout(bbox(2mm,invisible),"pdf");

```

Étiquettes :

## Asymptote and opacity – fig0140

Category: Asymptote,Examples 2D,OpacityPh. Ivaldi @ 5 h 54 min

 (Compiled with Asymptote version 1.87svn-r4652)
```
import edvenn_pi;

// Hue: Creates a color with the hue of the source color and the saturation
// and luminance of the backdrop color.
string blend="Hue";

size(10cm,0);

path [] edvenn= EdVenn(4);
pen [] fillp= new pen[]{black, red, green, blue};
pen p=linewidth(1mm);

for (int i=0; i<4; ++i) {
fillp[i]=fillp[i]+opacity(.5,blend=blend);
filldraw(edvenn[i], fillpen=fillp[i], drawpen=linewidth((i+1)*mm/2));
}

shipout(bbox(2mm,invisible),"pdf");

```

Étiquettes :

## Asymptote and opacity – fig0150

Category: Asymptote,Examples 2D,OpacityPh. Ivaldi @ 6 h 54 min

 (Compiled with Asymptote version 1.87svn-r4652)
```
import edvenn_pi;

// Saturation: Creates a color with the saturation of the source color and the hue
// and luminance of the backdrop color. Painting with this mode in an
// area of the backdrop that is a pure gray (no saturation) produces no
// change.
string blend="Saturation";

size(10cm,0);

path [] edvenn= EdVenn(4);
pen [] fillp= new pen[]{black, red, green, blue};
pen p=linewidth(1mm);

for (int i=0; i<4; ++i) {
fillp[i]=fillp[i]+opacity(.5,blend=blend);
filldraw(edvenn[i], fillpen=fillp[i], drawpen=linewidth((i+1)*mm/2));
}

shipout(bbox(2mm,invisible),"pdf");

```

Étiquettes :

## Asymptote and opacity – fig0160

Category: Asymptote,Examples 2D,OpacityPh. Ivaldi @ 7 h 54 min

 (Compiled with Asymptote version 1.87svn-r4652)
```
import edvenn_pi;

// Color: Creates a color with the hue and saturation of the source color and
// the luminance of the backdrop color. This preserves the gray levels
// of the backdrop and is useful for coloring monochrome images or
// tinting color images.
string blend="Color";

size(10cm,0);

path [] edvenn= EdVenn(4);
pen [] fillp= new pen[]{black, red, green, blue};
pen p=linewidth(1mm);

for (int i=0; i<4; ++i) {
fillp[i]=fillp[i]+opacity(.5,blend=blend);
filldraw(edvenn[i], fillpen=fillp[i], drawpen=linewidth((i+1)*mm/2));
}

shipout(bbox(2mm,invisible),"pdf");

```

Étiquettes :

## Asymptote and opacity – fig0170

Category: Asymptote,Examples 2D,OpacityPh. Ivaldi @ 8 h 54 min

 (Compiled with Asymptote version 1.87svn-r4652)
```
import edvenn_pi;

// Luminosity: Creates a color with the luminance of the source color and the hue
// and saturation of the backdrop color. This produces an inverse
// effect to that of the Color mode.
string blend="Luminosity";

size(10cm,0);

path [] edvenn= EdVenn(4);
pen [] fillp= new pen[]{black, red, green, blue};
pen p=linewidth(1mm);

for (int i=0; i<4; ++i) {
fillp[i]=fillp[i]+opacity(.5,blend=blend);
filldraw(edvenn[i], fillpen=fillp[i], drawpen=linewidth((i+1)*mm/2));
}

shipout(bbox(2mm,invisible),"pdf");

```

Étiquettes :

## Asymptote and opacity – fig0180

Category: Asymptote,Examples 2D,OpacityPh. Ivaldi @ 9 h 54 min

 (Compiled with Asymptote version 1.87svn-r4652)
```
size(4cm,0);
dotfactor*=5;

dot(scale(2)*"A",(0.5,1),5N);

layer();

dot(scale(2)*"B",(1.5,1),5N);
filldraw(scale(2)*unitsquare, lightgray+opacity(.5));

```

Étiquettes : , , , , , ,

## Asymptote and opacity – fig0190

Category: Asymptote,Examples 2D,OpacityPh. Ivaldi @ 10 h 54 min

 (Compiled with Asymptote version 1.87svn-r4652)
```
size(10cm,0);
transform T=rotate(10)*xscale(1.1);
path c1=T*unitcircle, c2=T*scale(5)*unitcircle;
real l1=length(c1), l2=length(c2);

fill(scale(8)*shift(-0.5,-0.5)*unitsquare,blue);
int n=500;
real step=1/n;
for (int i=0; i < n; ++i) {
real t=i*step;
path g1=subpath(c1,t*l1,(t+step)*l1);
path g2=subpath(c2,t*l2,(t+step)*l2);
pair A=(relpoint(c1,t)+relpoint(c2,t))/2;
pair B=(relpoint(c1,t+step)+relpoint(c2,t+step))/2;
path sector=g1--reverse(g2)--cycle;
pen trans=opacity(((2-(2*i/n)^1.5))/2);