Getting tile data from overworld

src/duskgl/display/shader/data/map.c

@@ -25,8 +25,8 @@ void mapInit() {
 void mapUpdate() {
   // Copy tile ids.
   memoryCopyRangeSafe(
-    &MAP_DATA.tileIds,
-    &OVERWORLD.tileIds[0],
+    MAP_DATA.tileIds,
+    OVERWORLD.tileIds,
     &OVERWORLD.tileIds[
       OVERWORLD.mapWidth * OVERWORLD.mapHeight * OVERWORLD.mapLayerCount
     ],

src/duskgl/display/shader/data/map.glsl

@@ -7,8 +7,10 @@
 #include "../fragments/packed.glsl"
 #include "../fragments/quad.glsl"
 
+#define MAP_TILE_PACKED_SIZE 16
+
 layout(std140) uniform b_Map {
-  uvec4 mapTileIds[OVERWORLD_TILE_COUNT_MAX / PACKED_U8_PER_UVEC4];
+  uvec4 mapTileIds[OVERWORLD_TILE_COUNT_MAX / MAP_TILE_PACKED_SIZE];
   uint mapSize;
   uvec3 _padding0;
 };
@@ -42,5 +44,6 @@ uint mapGetLayer(uint instanceIndex) {
 }
 
 uint mapGetTileId(uint instanceIndex) {
-  
+  uvec4 v4 = mapTileIds[packedArrayGetU8IndexFromUVEC4Array(instanceIndex)];
+  return packedArrayGetU8FromUVEC4ArrayValue(instanceIndex, v4);
 }

src/duskgl/display/shader/fragments/packed.glsl

@@ -4,13 +4,33 @@
 // https://opensource.org/licenses/MIT
 
 #define PACKED_U8_PER_UI 4
-#define PACKED_U8_PER_UVEC4 PACKED_U8_PER_UI / 4
+#define PACKED_U8_PER_UVEC4 PACKED_U8_PER_UI * 4
 
 uint packedGetU8(uint position, uint data) {
   return (data >> (position * 8u)) & 0xFFu;
 }
 
+uint packedGetU8FromVEC4(uint position, vec4 data) {
+  return packedGetU8(position, uint(data[position / 4u]));
+}
+
 int packedGetI8(uint position, uint data) {
   int shift = int(position * 8u);
   return int(data << (24 - shift)) >> 24;
+}
+
+uint packedArrayGetU8IndexFromUVEC4Array(uint u8ArrayIndex) {
+  // Given a uint8_t array is uploaded, this will return the index to get the
+  // appropriate uvec4 from a uvec4 array that will be at the right index.
+  return u8ArrayIndex / uint(PACKED_U8_PER_UVEC4);
+}
+
+uint packedArrayGetU8FromUVEC4ArrayValue(uint u8ArrayIndex, uvec4 data) {
+  // Given a value from a uint8_t array, this will return the value at the
+  // appropriate index. You must first get the uvec4 from the array using
+  // packedArrayGetU8IndexFromUVEC4Array.
+  uint subIndex = (u8ArrayIndex % uint(PACKED_U8_PER_UVEC4)) / uint(PACKED_U8_PER_UI);
+  uint shiftAmount = (u8ArrayIndex % uint(PACKED_U8_PER_UI)) * 8u;
+  uint value = (data[subIndex] >> shiftAmount) & 0xFFu;
+  return value;
 }

src/duskgl/display/shader/mapshader/map_frag.glsl

@@ -16,12 +16,13 @@ out vec4 FragColor;
 
 void main() {
   uint layer = mapGetLayer(v_InstanceIndex);
+  uint tileId = mapGetTileId(v_InstanceIndex);
 
-  if(layer == 0u) {
-    FragColor = vec4(1, 0, 0, 0.5);
+  if(tileId == 0u) {
+    FragColor = vec4(1, 0, 0, 1);
+  } else if(tileId == 1u) {
+    FragColor = vec4(0, 1, 0, 1);
   } else {
-    FragColor = vec4(0, 1, 0, 0.5);
+    FragColor = vec4(0, 0, 1, 1);
   }
-
-  // FragColor = vec4(1, 0, 0, 1);
 }