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| 157 | This one first takes a snapshot of the screen background image, and then |
157 | This one first takes a snapshot of the screen background image, and then |
| 158 | moves it to the upper left corner of the screen (as opposed to the upper |
158 | moves it to the upper left corner of the screen (as opposed to the upper |
| 159 | left corner of the terminal window)- the result is pseudo-transparency: |
159 | left corner of the terminal window)- the result is pseudo-transparency: |
| 160 | the image seems to be static while the window is moved around. |
160 | the image seems to be static while the window is moved around. |
| 161 | |
161 | |
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162 | =head2 COLOUR SPECIFICATIONS |
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163 | |
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164 | Whenever an oprator expects a "colour", then this can be specified in one |
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165 | of two ways: Either as string with an X11 colour specification, such as: |
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166 | |
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167 | "red" # named colour |
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168 | "#f00" # simple rgb |
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169 | "[50]red" # red with 50% alpha |
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170 | "TekHVC:300/50/50" # anything goes |
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171 | |
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172 | OR as an array reference with one, three or four components: |
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173 | |
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174 | [0.5] # 50% gray, 100% alpha |
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175 | [0.5, 0, 0] # dark red, no green or blur, 100% alpha |
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176 | [0.5, 0, 0, 0.7] # same with explicit 70% alpha |
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177 | |
| 162 | =head2 CACHING AND SENSITIVITY |
178 | =head2 CACHING AND SENSITIVITY |
| 163 | |
179 | |
| 164 | Since some operations (such as C<load> and C<blur>) can take a long time, |
180 | Since some operations (such as C<load> and C<blur>) can take a long time, |
| 165 | caching results can be very important for a smooth operation. Caching can |
181 | caching results can be very important for a smooth operation. Caching can |
| 166 | also be useful to reduce memory usage, though, for example, when an image |
182 | also be useful to reduce memory usage, though, for example, when an image |
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| 749 | =head2 COLOUR MODIFICATIONS |
765 | =head2 COLOUR MODIFICATIONS |
| 750 | |
766 | |
| 751 | The following operators change the pixels of the image. |
767 | The following operators change the pixels of the image. |
| 752 | |
768 | |
| 753 | =over 4 |
769 | =over 4 |
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770 | |
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771 | =item tint $color, $img |
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772 | |
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773 | Tints the image in the given colour. |
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774 | |
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775 | Example: tint the image red. |
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776 | |
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777 | tint "red", load "rgb.png" |
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778 | |
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779 | Example: the same, but specify the colour by component. |
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780 | |
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781 | tint [1, 0, 0], load "rgb.png" |
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782 | |
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783 | =cut |
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784 | |
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785 | sub tint($$) { |
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786 | $_[1]->tint ($_[0]) |
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787 | } |
| 754 | |
788 | |
| 755 | =item contrast $factor, $img |
789 | =item contrast $factor, $img |
| 756 | |
790 | |
| 757 | =item contrast $r, $g, $b, $img |
791 | =item contrast $r, $g, $b, $img |
| 758 | |
792 | |
