projects / imager.git / blame
| Commit | Line | Data |
|---|---|---|
| bea65b1f TC |
1 | /* |
| 2 | Imager "functions" implemented as macros | |
| 3 | ||
| 4 | I suppose these could go in imdatatypes, but they aren't types. | |
| 5 | */ | |
| 6 | #ifndef IMAGER_IMMACROS_H_ | |
| 7 | #define IMAGER_IMMACROS_H_ | |
| 8 | ||
| 9 | /* | |
| 5715f7c3 | 10 | =item i_img_has_alpha(C<im>) |
| bea65b1f TC |
11 | |
| 12 | =category Image Information | |
| 13 | ||
| 14 | Return true if the image has an alpha channel. | |
| 15 | ||
| 16 | =cut | |
| 17 | */ | |
| 18 | ||
| 19 | #define i_img_has_alpha(im) ((im)->channels == 2 || (im)->channels == 4) | |
| 20 | ||
| 21 | /* | |
| 5715f7c3 | 22 | =item i_img_color_channels(C<im>) |
| bea65b1f TC |
23 | |
| 24 | =category Image Information | |
| 25 | ||
| 26 | The number of channels holding color information. | |
| 27 | ||
| 28 | =cut | |
| 29 | */ | |
| 30 | ||
| 31 | #define i_img_color_channels(im) (i_img_has_alpha(im) ? (im)->channels - 1 : (im)->channels) | |
| 32 | ||
| 836d9f54 TC |
33 | /* |
| 34 | =item i_psamp(im, left, right, y, samples, channels, channel_count) | |
| 35 | =category Drawing | |
| 36 | ||
| 37 | Writes sample values from C<samples> to C<im> for the horizontal line | |
| 38 | (left, y) to (right-1, y) inclusive for the channels specified by | |
| 39 | C<channels>, an array of C<int> with C<channel_count> elements. | |
| 40 | ||
| 41 | If C<channels> is C<NULL> then the first C<channels_count> channels | |
| 42 | are written to for each pixel. | |
| 43 | ||
| 44 | Returns the number of samples written, which should be (right - left) | |
| 45 | * channel_count. If a channel not in the image is in channels, left | |
| 46 | is negative, left is outside the image or y is outside the image, | |
| 47 | returns -1 and pushes an error. | |
| 48 | ||
| 49 | =cut | |
| 50 | */ | |
| 51 | ||
| 52 | #define i_psamp(im, l, r, y, samps, chans, count) \ | |
| 53 | (((im)->i_f_psamp)((im), (l), (r), (y), (samps), (chans), (count))) | |
| 54 | ||
| 55 | /* | |
| 56 | =item i_psampf(im, left, right, y, samples, channels, channel_count) | |
| 57 | =category Drawing | |
| 58 | ||
| 59 | Writes floating point sample values from C<samples> to C<im> for the | |
| 60 | horizontal line (left, y) to (right-1, y) inclusive for the channels | |
| 61 | specified by C<channels>, an array of C<int> with C<channel_count> | |
| 62 | elements. | |
| 63 | ||
| 64 | If C<channels> is C<NULL> then the first C<channels_count> channels | |
| 65 | are written to for each pixel. | |
| 66 | ||
| 67 | Returns the number of samples written, which should be (right - left) | |
| 68 | * channel_count. If a channel not in the image is in channels, left | |
| 69 | is negative, left is outside the image or y is outside the image, | |
| 70 | returns -1 and pushes an error. | |
| 71 | ||
| 72 | =cut | |
| 73 | */ | |
| 74 | ||
| 75 | #define i_psampf(im, l, r, y, samps, chans, count) \ | |
| 76 | (((im)->i_f_psampf)((im), (l), (r), (y), (samps), (chans), (count))) | |
| 77 | ||
| bea65b1f | 78 | #endif |