Lichen, Extraterrestrials, Diodes #0

2018-04-21, post № 195

art, #LED, #photography


Third Anniversary

2018-03-28, post № 194

, #2017, #collage

Today marks this blog’s third anniversary. To celebrate and take a look back at the year, I have collected a few image highlights.


BMP Implementation in C — Graphic Primitives

2018-03-24, post № 193

C, programming, #2017, #bitmap, #bmp, #drawing, #image library, #image manipulation, #library

Continuing development of my C bitmap library, I added basic graphic primitives to augment the library’s functionality beyond simply reading and writing bitmaps and manually manipulating individual pixels. Source code can be seen below and also downloaded — bmp.c.
The underlying implementation of the bitmap file format can be seen in my prior post BMP Implementation in C.Graphic primitives include drawing lines, rectangles, circles, ellipses; rotating, flipping, cropping, resizing and blitting images. A full list of defined graphic primitives can be seen below, together with a short functionality description.

Test image regarding drawing primitives.
void hline      (image *img, int x0, int x1, int y , int c               ); // draw horizontal line
void vline      (image *img, int x , int y0, int y1, int c               ); // draw vertical line
void line       (image *img, int x0, int y0, int x1, int y1, int c       ); // draw line
void fillrect   (image *img, int x0, int y0, int x1, int y1, int c       ); // draw filled rectangle
void rect       (image *img, int x0, int y0, int x1, int y1, int c       ); // draw rectangle
void fillcircle (image *img, int x , int y , int r , int c               ); // draw filled circle
void circle     (image *img, int x , int y , int r , int t , int c       ); // draw circle (with certain thickness)
void fillellipse(image *img, int x , int y , int rx, int ry, int c       ); // draw filled ellipse
void ellipse    (image *img, int x , int y , int rx, int ry, int t, int c); // draw ellipse (with certain thickness)

image *resize   (image *img, int w , int h                                ); // resize an image
image *hflip    (image *img                                               ); // flip horizontally
image *vflip    (image *img                                               ); // flip vertically
image *rrotate  (image *img                                               ); // rotate clockwise
image *lrotate  (image *img                                               ); // rotate counter-clockwise
image *hrotate  (image *img                                               ); // rotate half a revolution
image *crop     (image *img, int x0, int y0, int x1, int y1               ); // crop an image
void   blit     (image *img, image*, int x , int y                        ); // blit an image onto another one
Test image regarding transformation primitives.

Future plans for this library include performance optimizations regarding the ellipse drawing primitives; circle drawing is already optimized as it uses the shape’s symmetry to save computational cost.Further primitives that may be added include a flood filling functionality as well as the ability to draw irregular polygons.

Source code: bmp.c
Jonathan Frech's blog; built 2021/04/16 21:21:49 CEST