convert colour to a 2 bit format

src/game/game.c

@@ -3,11 +3,10 @@
 #include <stdbool.h>
 
 #include "../main.h"
-#include "../window/renderer.h"
 #include "shapes.h"
 
 
-static void _add_shape(Row* row, const Shape shape, const uint8_t colour, const uint8_t pos_x) {
+static void _add_shape(Row* row, const Shape shape, const Colour colour, const uint8_t pos_x) {
     for (uint8_t y = 0; y < SHAPE_HEIGHT; y++) {
         ShapeRow shape_row = shape_get_row(shape, y);
 
@@ -16,11 +15,11 @@ static void _add_shape(Row* row, const Shape shape, const uint8_t colour, const
 
         for (uint8_t x = 0; x < SHAPE_WIDTH; x++)
             if (is_set(shape_row, x))
-                row[y].columns[x + pos_x].block = colour;
+                row[y].columns[x + pos_x] = colour;
     }
 }
 
-static inline void add_shape(Row* row, const Shape shape, const uint8_t colour, const uint8_t pos_x, const uint8_t pos_y) {
+static inline void add_shape(Row* row, const Shape shape, const Colour colour, const uint8_t pos_x, const uint8_t pos_y) {
     _add_shape(&row[pos_y], shape, colour, pos_x);
 }
 
@@ -30,14 +29,14 @@ void game_update(GameData* game_data, const Uint8* keys) {
         stop();
     }
 
-    add_shape(game_data->row, TETROMINO_I, CYAN, 1, 0);
+    add_shape(game_data->row, TETROMINO_I, COLOUR_CYAN, 1, 0);
-    add_shape(game_data->row, TETROMINO_O, YELLOW, 5, 4);
+    add_shape(game_data->row, TETROMINO_O, COLOUR_YELLOW, 5, 4);
 
-    add_shape(game_data->row, TETROMINO_Z, GREEN, 1, 8);
+    add_shape(game_data->row, TETROMINO_Z, COLOUR_GREEN, 1, 8);
-    add_shape(game_data->row, TETROMINO_S, RED, 5, 8);
+    add_shape(game_data->row, TETROMINO_S, COLOUR_RED, 5, 8);
 
-    add_shape(game_data->row, TETROMINO_J, BLUE, 1, 12);
+    add_shape(game_data->row, TETROMINO_J, COLOUR_BLUE, 1, 12);
-    add_shape(game_data->row, TETROMINO_L, YELLOW | RED, 5, 12);
+    add_shape(game_data->row, TETROMINO_L, COLOUR_ORANGE, 5, 12);
 
-    add_shape(game_data->row, TETROMINO_T, MAGENTA, 5, 16);
+    add_shape(game_data->row, TETROMINO_T, COLOUR_MAGENTA, 5, 16);
 }

src/game/game.h

@@ -1,18 +1,16 @@
 #pragma once
 #include <SDL2/SDL.h>
 
+#include "../window/colour.h"
+
 typedef uint32_t PackedRow;
 
 // stores the data used in the game
 #define COLUMNS ((uint8_t)(sizeof(PackedRow) * 8 / 3))
 #define ROWS ((uint8_t)(COLUMNS * 2))
 
-typedef union {
+typedef struct {
-    // NOTE: this has packing issues
+    Colour columns[COLUMNS];
-    struct {
-        uint8_t block : 3;
-    } columns[COLUMNS];
-    PackedRow val;
 } Row;
 
 typedef struct {

src/window/colour.h

@@ -0,0 +1,22 @@
+#pragma once
+
+// fits colours with each channel having a width of 2 bits
+#include <stdint.h>
+
+typedef union {
+    uint8_t packed;
+    struct {
+        uint8_t a : 2;
+        uint8_t b : 2;
+        uint8_t g : 2;
+        uint8_t r : 2;
+    };
+} Colour;
+
+#define COLOUR_RED      ((Colour){0b11000011})
+#define COLOUR_YELLOW   ((Colour){0b11110011})
+#define COLOUR_ORANGE   ((Colour){0b11100011})
+#define COLOUR_GREEN    ((Colour){0b00110011})
+#define COLOUR_CYAN     ((Colour){0b00111111})
+#define COLOUR_BLUE     ((Colour){0b00001111})
+#define COLOUR_MAGENTA  ((Colour){0b11001111})

src/window/renderer.c

@@ -5,6 +5,7 @@
 #include <stdio.h>
 
 #include "../errors.h"
+#include "colour.h"
 #include "renderer.h"
 
 
@@ -40,12 +41,12 @@ void renderer_update(const RenderData* render_data) {
         Row row = data->row[y];
 
         for (uint8_t x = 0; x < COLUMNS; x++) {
-            if (row.columns[x].block != 0) {
+            if (row.columns[x].packed != 0) {
                 success |= SDL_SetRenderDrawColor(renderer,
-                                                  0xFF * !!(row.columns[x].block & RED),
+                                                  0x55 * row.columns[x].r, // repeat the 2 bits by multiplying by 0x55
-                                                  0xFF * !!(row.columns[x].block & GREEN),
+                                                  0x55 * row.columns[x].g,
-                                                  0xFF * !!(row.columns[x].block & BLUE),
+                                                  0x55 * row.columns[x].b,
-                                                  0xFF);
+                                                  0x55 * row.columns[x].a);
                 success |= SDL_RenderFillRect(renderer, &(SDL_Rect){x * BLOCK_WIDTH + 1, y * BLOCK_HEIGHT + 1, BLOCK_WIDTH - 1, BLOCK_HEIGHT - 1});
             }
         }

src/window/renderer.h

@@ -1,5 +1,6 @@
 #pragma once
 #include <SDL2/SDL.h>
+#include <stdint.h>
 
 #include "../game/game.h"
 
@@ -8,19 +9,6 @@
 #define BLOCK_WIDTH (SCREEN_WIDTH / COLUMNS)
 #define BLOCK_HEIGHT (SCREEN_HEIGHT / ROWS)
 
-// fits colours in a 3 bit length
-// 4th bit is unused
-typedef enum {
-    BLACK = 0,
-    RED = 1,
-    GREEN = 2,
-    BLUE = 4,
-    YELLOW = RED | GREEN,
-    CYAN = GREEN | BLUE,
-    MAGENTA = BLUE | RED,
-    WHITE = RED | GREEN | BLUE,
-} Colour;
-
 typedef struct {
     SDL_Window* window;
     SDL_Renderer* renderer;