diff options
Diffstat (limited to 'src/lolwut5.c')
-rw-r--r-- | src/lolwut5.c | 119 |
1 files changed, 7 insertions, 112 deletions
diff --git a/src/lolwut5.c b/src/lolwut5.c index 8408b378d..5a9348800 100644 --- a/src/lolwut5.c +++ b/src/lolwut5.c @@ -34,17 +34,9 @@ */ #include "server.h" +#include "lolwut.h" #include <math.h> -/* This structure represents our canvas. Drawing functions will take a pointer - * to a canvas to write to it. Later the canvas can be rendered to a string - * suitable to be printed on the screen, using unicode Braille characters. */ -typedef struct lwCanvas { - int width; - int height; - char *pixels; -} lwCanvas; - /* Translate a group of 8 pixels (2x4 vertical rectangle) to the corresponding * braille character. The byte should correspond to the pixels arranged as * follows, where 0 is the least significant bit, and 7 the most significant @@ -69,104 +61,6 @@ void lwTranslatePixelsGroup(int byte, char *output) { output[2] = 0x80 | (code & 0x3F); /* 10-xxxxxx */ } -/* Allocate and return a new canvas of the specified size. */ -lwCanvas *lwCreateCanvas(int width, int height) { - lwCanvas *canvas = zmalloc(sizeof(*canvas)); - canvas->width = width; - canvas->height = height; - canvas->pixels = zmalloc(width*height); - memset(canvas->pixels,0,width*height); - return canvas; -} - -/* Free the canvas created by lwCreateCanvas(). */ -void lwFreeCanvas(lwCanvas *canvas) { - zfree(canvas->pixels); - zfree(canvas); -} - -/* Set a pixel to the specified color. Color is 0 or 1, where zero means no - * dot will be displyed, and 1 means dot will be displayed. - * Coordinates are arranged so that left-top corner is 0,0. You can write - * out of the size of the canvas without issues. */ -void lwDrawPixel(lwCanvas *canvas, int x, int y, int color) { - if (x < 0 || x >= canvas->width || - y < 0 || y >= canvas->height) return; - canvas->pixels[x+y*canvas->width] = color; -} - -/* Return the value of the specified pixel on the canvas. */ -int lwGetPixel(lwCanvas *canvas, int x, int y) { - if (x < 0 || x >= canvas->width || - y < 0 || y >= canvas->height) return 0; - return canvas->pixels[x+y*canvas->width]; -} - -/* Draw a line from x1,y1 to x2,y2 using the Bresenham algorithm. */ -void lwDrawLine(lwCanvas *canvas, int x1, int y1, int x2, int y2, int color) { - int dx = abs(x2-x1); - int dy = abs(y2-y1); - int sx = (x1 < x2) ? 1 : -1; - int sy = (y1 < y2) ? 1 : -1; - int err = dx-dy, e2; - - while(1) { - lwDrawPixel(canvas,x1,y1,color); - if (x1 == x2 && y1 == y2) break; - e2 = err*2; - if (e2 > -dy) { - err -= dy; - x1 += sx; - } - if (e2 < dx) { - err += dx; - y1 += sy; - } - } -} - -/* Draw a square centered at the specified x,y coordinates, with the specified - * rotation angle and size. In order to write a rotated square, we use the - * trivial fact that the parametric equation: - * - * x = sin(k) - * y = cos(k) - * - * Describes a circle for values going from 0 to 2*PI. So basically if we start - * at 45 degrees, that is k = PI/4, with the first point, and then we find - * the other three points incrementing K by PI/2 (90 degrees), we'll have the - * points of the square. In order to rotate the square, we just start with - * k = PI/4 + rotation_angle, and we are done. - * - * Of course the vanilla equations above will describe the square inside a - * circle of radius 1, so in order to draw larger squares we'll have to - * multiply the obtained coordinates, and then translate them. However this - * is much simpler than implementing the abstract concept of 2D shape and then - * performing the rotation/translation transformation, so for LOLWUT it's - * a good approach. */ -void lwDrawSquare(lwCanvas *canvas, int x, int y, float size, float angle) { - int px[4], py[4]; - - /* Adjust the desired size according to the fact that the square inscribed - * into a circle of radius 1 has the side of length SQRT(2). This way - * size becomes a simple multiplication factor we can use with our - * coordinates to magnify them. */ - size /= 1.4142135623; - size = round(size); - - /* Compute the four points. */ - float k = M_PI/4 + angle; - for (int j = 0; j < 4; j++) { - px[j] = round(sin(k) * size + x); - py[j] = round(cos(k) * size + y); - k += M_PI/2; - } - - /* Draw the square. */ - for (int j = 0; j < 4; j++) - lwDrawLine(canvas,px[j],py[j],px[(j+1)%4],py[(j+1)%4],1); -} - /* Schotter, the output of LOLWUT of Redis 5, is a computer graphic art piece * generated by Georg Nees in the 60s. It explores the relationship between * caos and order. @@ -180,7 +74,7 @@ lwCanvas *lwDrawSchotter(int console_cols, int squares_per_row, int squares_per_ int padding = canvas_width > 4 ? 2 : 0; float square_side = (float)(canvas_width-padding*2) / squares_per_row; int canvas_height = square_side * squares_per_col + padding*2; - lwCanvas *canvas = lwCreateCanvas(canvas_width, canvas_height); + lwCanvas *canvas = lwCreateCanvas(canvas_width, canvas_height, 0); for (int y = 0; y < squares_per_col; y++) { for (int x = 0; x < squares_per_row; x++) { @@ -200,7 +94,7 @@ lwCanvas *lwDrawSchotter(int console_cols, int squares_per_row, int squares_per_ sx += r2*square_side/3; sy += r3*square_side/3; } - lwDrawSquare(canvas,sx,sy,square_side,angle); + lwDrawSquare(canvas,sx,sy,square_side,angle,1); } } @@ -212,7 +106,7 @@ lwCanvas *lwDrawSchotter(int console_cols, int squares_per_row, int squares_per_ * logical canvas. The actual returned string will require a terminal that is * width/2 large and height/4 tall in order to hold the whole image without * overflowing or scrolling, since each Barille character is 2x4. */ -sds lwRenderCanvas(lwCanvas *canvas) { +static sds renderCanvas(lwCanvas *canvas) { sds text = sdsempty(); for (int y = 0; y < canvas->height; y += 4) { for (int x = 0; x < canvas->width; x += 2) { @@ -272,11 +166,12 @@ void lolwut5Command(client *c) { /* Generate some computer art and reply. */ lwCanvas *canvas = lwDrawSchotter(cols,squares_per_row,squares_per_col); - sds rendered = lwRenderCanvas(canvas); + sds rendered = renderCanvas(canvas); rendered = sdscat(rendered, "\nGeorg Nees - schotter, plotter on paper, 1968. Redis ver. "); rendered = sdscat(rendered,REDIS_VERSION); rendered = sdscatlen(rendered,"\n",1); - addReplyBulkSds(c,rendered); + addReplyVerbatim(c,rendered,sdslen(rendered),"txt"); + sdsfree(rendered); lwFreeCanvas(canvas); } |