WIP refactor

graphics.c

@@ -0,0 +1,92 @@
+
+#include "graphics.h"
+#include "common.h"
+#include "util.h"
+
+#include <stdio.h>
+
+/** Set background to dark blue */
+#define BG_DARKBLUE()  setcolor(0, 100, 100, 150)
+
+/** Set background to light blue */
+#define BG_LIGHTBLUE() setcolor(0, 150, 150, 200)
+
+/** Set foreground to black */
+#define FG_BLACK()     setcolor(1, 0, 0, 0)
+
+/** Set foreground to white */
+#define FG_WHITE()     setcolor(1, 0xff, 0xff, 0xff)
+
+/** 0x2659 == ♙ */
+#define UNICODE_CHESS_SYMBOL 0x2659
+
+static inline void setcolor(const int mode, const int r, const int g, const int b);
+
+/**
+ * Sets the foreground or background color for subsequent writes.
+ *
+ * Uses Select Graphic Renditions (SGR) to set the color of the terminal output.
+ * See https://en.wikipedia.org/wiki/ANSI_escape_code#24-bit for more details.
+ *
+ * \param mode 0 - change background, 1 - change foreground, 2 - reset colors
+ * \param r    amount of red (0 to 255)
+ * \param b    amount of blue (0 to 255)
+ * \param g    amount of green (0 to 255)
+ */
+static inline void setcolor(const int mode, const int r, const int g, const int b)
+{
+    if (mode == 2)
+        printf("\033[0m");
+    else
+        printf("\033[%i;2;%i;%i;%im", mode ? 38 : 48, r, g, b);
+};
+
+/**
+ * Prints the board
+ *
+ * Uses unicode symbols and ANSI escape features to print a chessboard on the
+ * display.
+ *
+ * \param board A pointer to a list of tiles representing the board state
+ *
+ * */
+void print_board(const tile_t board[BOARD_SIZE])
+{
+    /* https://en.wikipedia.org/wiki/Chess_symbols_in_Unicode
+
+       The unicode symbols for the pieces are calculated from adding
+           0x2653 (#define'd as UNICODE_CHESS_SYMBOL) with the piece value. */
+
+    for (size_t i = 0; i < 8; i++) {
+        printf("\n %zu ", 8 - i); // number coordinates
+
+        for (size_t j = 0; j < 8; j++) {
+            tile_t t = board[i * 8 + j];
+
+            if ((i + j) % 2)
+                BG_DARKBLUE();
+            else
+                BG_LIGHTBLUE();
+
+            if (tile_empty(t)) {
+                printf("  ");
+                continue;
+            }
+
+            if (t > 0)
+                FG_WHITE();
+            else
+                FG_BLACK();
+
+            printf("%lc ", UNICODE_CHESS_SYMBOL + abs_tile(t));
+        }
+
+        setcolor(2, 0, 0, 0); // reset text attributes
+    }
+
+    /* horizontal letter coordinates */
+    printf("\n  ");
+
+    for (int i = 0; i < 8; i++)
+        printf(" %c", 'a' + i);
+}