Adding upstream version 5:7.2.4.upstream/5%7.2.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 201 insertions, 0 deletions

diff --git a/src/lolwut6.c b/src/lolwut6.c
new file mode 100644
index 0000000..1ba111c
--- /dev/null
+++ b/src/lolwut6.c
@@ -0,0 +1,201 @@
+/*
+ * Copyright (c) 2019, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * This file implements the LOLWUT command. The command should do something
+ * fun and interesting, and should be replaced by a new implementation at
+ * each new version of Redis.
+ *
+ * Thanks to Michele Hiki Falcone for the original image that inspired
+ * the image, part of his game, Plaguemon.
+ *
+ * Thanks to the Shhh computer art collective for the help in tuning the
+ * output to have a better artistic effect.
+ */
+
+#include "server.h"
+#include "lolwut.h"
+
+/* Render the canvas using the four gray levels of the standard color
+ * terminal: they match very well to the grayscale display of the gameboy. */
+static sds renderCanvas(lwCanvas *canvas) {
+    sds text = sdsempty();
+    for (int y = 0; y < canvas->height; y++) {
+        for (int x = 0; x < canvas->width; x++) {
+            int color = lwGetPixel(canvas,x,y);
+            char *ce; /* Color escape sequence. */
+
+            /* Note that we set both the foreground and background color.
+             * This way we are able to get a more consistent result among
+             * different terminals implementations. */
+            switch(color) {
+            case 0: ce = "0;30;40m"; break;    /* Black */
+            case 1: ce = "0;90;100m"; break;   /* Gray 1 */
+            case 2: ce = "0;37;47m"; break;    /* Gray 2 */
+            case 3: ce = "0;97;107m"; break;   /* White */
+            default: ce = "0;30;40m"; break;   /* Just for safety. */
+            }
+            text = sdscatprintf(text,"\033[%s \033[0m",ce);
+        }
+        if (y != canvas->height-1) text = sdscatlen(text,"\n",1);
+    }
+    return text;
+}
+
+/* Draw a skyscraper on the canvas, according to the parameters in the
+ * 'skyscraper' structure. Window colors are random and are always one
+ * of the two grays. */
+struct skyscraper {
+    int xoff;       /* X offset. */
+    int width;      /* Pixels width. */
+    int height;     /* Pixels height. */
+    int windows;    /* Draw windows if true. */
+    int color;      /* Color of the skyscraper. */
+};
+
+void generateSkyscraper(lwCanvas *canvas, struct skyscraper *si) {
+    int starty = canvas->height-1;
+    int endy = starty - si->height + 1;
+    for (int y = starty; y >= endy; y--) {
+        for (int x = si->xoff; x < si->xoff+si->width; x++) {
+            /* The roof is four pixels less wide. */
+            if (y == endy && (x <= si->xoff+1 || x >= si->xoff+si->width-2))
+                continue;
+            int color = si->color;
+            /* Alter the color if this is a place where we want to
+             * draw a window. We check that we are in the inner part of the
+             * skyscraper, so that windows are far from the borders. */
+            if (si->windows &&
+                x > si->xoff+1 &&
+                x < si->xoff+si->width-2 &&
+                y > endy+1 &&
+                y < starty-1)
+            {
+                /* Calculate the x,y position relative to the start of
+                 * the window area. */
+                int relx = x - (si->xoff+1);
+                int rely = y - (endy+1);
+
+                /* Note that we want the windows to be two pixels wide
+                 * but just one pixel tall, because terminal "pixels"
+                 * (characters) are not square. */
+                if (relx/2 % 2 && rely % 2) {
+                    do {
+                        color = 1 + rand() % 2;
+                    } while (color == si->color);
+                    /* Except we want adjacent pixels creating the same
+                     * window to be the same color. */
+                    if (relx % 2) color = lwGetPixel(canvas,x-1,y);
+                }
+            }
+            lwDrawPixel(canvas,x,y,color);
+        }
+    }
+}
+
+/* Generate a skyline inspired by the parallax backgrounds of 8 bit games. */
+void generateSkyline(lwCanvas *canvas) {
+    struct skyscraper si;
+
+    /* First draw the background skyscraper without windows, using the
+     * two different grays. We use two passes to make sure that the lighter
+     * ones are always in the background. */
+    for (int color = 2; color >= 1; color--) {
+        si.color = color;
+        for (int offset = -10; offset < canvas->width;) {
+            offset += rand() % 8;
+            si.xoff = offset;
+            si.width = 10 + rand()%9;
+            if (color == 2)
+                si.height = canvas->height/2 + rand()%canvas->height/2;
+            else
+                si.height = canvas->height/2 + rand()%canvas->height/3;
+            si.windows = 0;
+            generateSkyscraper(canvas, &si);
+            if (color == 2)
+                offset += si.width/2;
+            else
+                offset += si.width+1;
+        }
+    }
+
+    /* Now draw the foreground skyscraper with the windows. */
+    si.color = 0;
+    for (int offset = -10; offset < canvas->width;) {
+        offset += rand() % 8;
+        si.xoff = offset;
+        si.width = 5 + rand()%14;
+        if (si.width % 4) si.width += (si.width % 3);
+        si.height = canvas->height/3 + rand()%canvas->height/2;
+        si.windows = 1;
+        generateSkyscraper(canvas, &si);
+        offset += si.width+5;
+    }
+}
+
+/* The LOLWUT 6 command:
+ *
+ * LOLWUT [columns] [rows]
+ *
+ * By default the command uses 80 columns, 40 squares per row
+ * per column.
+ */
+void lolwut6Command(client *c) {
+    long cols = 80;
+    long rows = 20;
+
+    /* Parse the optional arguments if any. */
+    if (c->argc > 1 &&
+        getLongFromObjectOrReply(c,c->argv[1],&cols,NULL) != C_OK)
+        return;
+
+    if (c->argc > 2 &&
+        getLongFromObjectOrReply(c,c->argv[2],&rows,NULL) != C_OK)
+        return;
+
+    /* Limits. We want LOLWUT to be always reasonably fast and cheap to execute
+     * so we have maximum number of columns, rows, and output resolution. */
+    if (cols < 1) cols = 1;
+    if (cols > 1000) cols = 1000;
+    if (rows < 1) rows = 1;
+    if (rows > 1000) rows = 1000;
+
+    /* Generate the city skyline and reply. */
+    lwCanvas *canvas = lwCreateCanvas(cols,rows,3);
+    generateSkyline(canvas);
+    sds rendered = renderCanvas(canvas);
+    rendered = sdscat(rendered,
+        "\nDedicated to the 8 bit game developers of past and present.\n"
+        "Original 8 bit image from Plaguemon by hikikomori. Redis ver. ");
+    rendered = sdscat(rendered,REDIS_VERSION);
+    rendered = sdscatlen(rendered,"\n",1);
+    addReplyVerbatim(c,rendered,sdslen(rendered),"txt");
+    sdsfree(rendered);
+    lwFreeCanvas(canvas);
+}