4 files changed, 100 insertions(+), 0 deletions(-)

A .editorconfig
A 10print.c
A LICENSE.txt
A README.md

@@ 1,9 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 4
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true

@@ 1,58 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define GRID_WIDTH 15
+#define GRID_HEIGHT 5
+#define TILE_SIZE_PX 100
+#define DRAW_WIDTH 25
+#define FG_R 16 * 15
+#define FG_G 16 * 11
+#define FG_B 16 * 12
+#define BG_R 16 * 15
+#define BG_G 16 * 14
+#define BG_B 16 * 13
+
+void print_line(int y, int which)
+{
+    for (int x = 0; x < TILE_SIZE_PX; ++x) {
+        int dist = (which == 0 ? abs(x - y) : abs(TILE_SIZE_PX - 1 - x - y));
+        if (dist <= DRAW_WIDTH) {
+            printf("%d %d %d\n", FG_R, FG_G, FG_B);
+        } else if (dist == DRAW_WIDTH + 1) {
+            /* Anti-alias */
+            printf("%d %d %d\n",
+                (FG_R + BG_R) / 2,
+                (FG_G + BG_G) / 2,
+                (FG_B + BG_B) / 2);
+        } else {
+            printf("%d %d %d\n", BG_R, BG_G, BG_B);
+        }
+    }
+}
+
+int main(void) {
+    int row_tiles[GRID_WIDTH];
+
+    srand(22);
+
+    /* Print the header */
+    printf("P3\n");
+    printf("%d %d\n", GRID_WIDTH * TILE_SIZE_PX, GRID_HEIGHT * TILE_SIZE_PX);
+    printf("255\n");
+
+    for (int grid_row = 0; grid_row < GRID_HEIGHT; ++grid_row) {
+        /* Select the tiles for this row */
+        for (int grid_col = 0; grid_col < GRID_WIDTH; ++grid_col) {
+            row_tiles[grid_col] = rand() % 2;
+        }
+
+        /* Draw the tiles for this row */
+        for (int y = 0; y < TILE_SIZE_PX; ++y) {
+            for (int grid_col = 0; grid_col < GRID_WIDTH; ++grid_col) {
+                print_line(y, row_tiles[grid_col]);
+            }
+        }
+    }
+
+    return EXIT_SUCCESS;
+}

@@ 1,21 @@
+MIT License
+
+Copyright (c) 2021 Simon Bates
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

@@ 1,12 @@
+Generates an image in the style of the Commodore 64 program
+[`10 PRINT CHR$(205.5+RND(1)); : GOTO 10`](https://10print.org/)
+
+Usage:
+
+* Edit the `#define` statements to set the colours and size
+* Change the seed in the `srand()` call to make a different pattern
+
+Then compile and run:
+
+    cc 10print.c
+    ./a.out > image.ppm