Add gold support

- added gold layer to the map
- the player can collect gold
- updates the score
- TODO: end of stage

1 files changed, 66 insertions, 0 deletions

diff --git a/src/map.c b/src/map.c
index 87a0b3b..9908384 100644
--- a/src/map.c
+++ b/src/map.c
@@ -1,4 +1,5 @@
 #include <stdint.h>
+#include <string.h>
 
 #include "vga.h"
 #include "data.h"
@@ -7,10 +8,22 @@
 
 /* current map; set via map_init */
 static const uint8_t *cmap;
+static uint8_t gold[MAP_W * MAP_H];
+static uint8_t total_gold;
 
 void map_init(const uint8_t map[])
 {
     cmap = map;
+
+    /* make a copy of the gold data in RAM */
+    memcpy(gold, cmap + MAP_W * MAP_H, MAP_W * MAP_H);
+
+    /* count how many pieces of gold on this map */
+    total_gold = 0;
+    for (uint16_t i = 0; i < MAP_W * MAP_H; i++)
+        /* gold is not 0xff */
+        if (gold[i] != 0xff)
+            total_gold++;
 }
 
 void map_render()
@@ -30,6 +43,24 @@ void map_render()
 
             blitrc(binary_tiles_start, &src, &dst);
         }
+
+    for (uint8_t y = 0; y < MAP_H; y++)
+        for (uint8_t x = 0; x < MAP_W; x++)
+        {
+            dst.x = x * MAP_TILE_W;
+            dst.y = y * MAP_TILE_H + MAP_OFFS_Y;
+
+            uint8_t t = gold[x + y * MAP_W];
+
+            /* not gold, skip! */
+            if (t == 0xff)
+                continue;
+
+            src.x = (t % MAP_TILESET_COLS) * MAP_TILE_W;
+            src.y = (t / MAP_TILESET_COLS) * MAP_TILE_H;
+
+            blitrc(binary_tiles_start, &src, &dst);
+        }
 }
 
 uint8_t map_is_blocked(uint16_t x, uint16_t y)
@@ -41,3 +72,38 @@ uint8_t map_is_deadly(uint16_t x, uint16_t y)
 {
     return cmap[(x / MAP_TILE_W) + (y / MAP_TILE_H) * MAP_W] >= MAP_FIRST_DEADLY;
 }
+
+uint8_t map_update_gold(uint16_t x, uint16_t y)
+{
+    Rect src = { 0, 0, 160, 48 };
+    Rect dst = { 0, 0, 8, 8 };
+
+    uint16_t mx = x / MAP_TILE_W;
+    uint16_t my = y / MAP_TILE_H;
+
+    if (gold[mx + my * MAP_W] != 0xff)
+    {
+        /* this gold is collected */
+        gold[mx + my * MAP_W] = 0xff;
+
+        /* erase the background */
+        dst.x = mx * MAP_TILE_W;
+        dst.y = my * MAP_TILE_H + MAP_OFFS_Y;
+
+        uint8_t t = cmap[mx + my * MAP_W];
+        src.x = (t % MAP_TILESET_COLS) * MAP_TILE_W;
+        src.y = (t / MAP_TILESET_COLS) * MAP_TILE_H;
+
+        blitrc(binary_tiles_start, &src, &dst);
+
+        total_gold--;
+        return 1;
+    }
+
+    return 0;
+}
+
+uint8_t map_is_complete()
+{
+    return total_gold == 0;
+}