Start atlas

2025-06-01 22:13:02 +02:00
parent 96a9a45c20
commit 84805b92cb
64 changed files with 954 additions and 243 deletions
--- a/util/atlas.c
+++ b/util/atlas.c
@@ -0,0 +1,80 @@
+//
+// Created by bruno on 1.6.2025.
+//
+
+#include "atlas.h"
+#include "util.h"
+
+SDL_Texture *atlasTexture;
+
+int atlasX = 0, atlasY = 0;
+
+int tileIndex = 0;        // Which 32x32 tile we're on
+int quadrantIndex = 0;    // Which 16x16 slot inside that tile
+
+
+
+SDL_Rect allocate_16x16(SDL_Texture *srcTexture, SDL_Renderer *renderer) {
+    SDL_Texture * oldTarget = SDL_GetRenderTarget(renderer);
+    SDL_SetRenderTarget(renderer, atlasTexture);
+    int tileX = tileIndex % ATLAS_TILES_PER_ROW;
+    int tileY = tileIndex / ATLAS_TILES_PER_ROW;
+
+    int dx = (quadrantIndex % 2) * QUADRANT_SIZE;
+    int dy = (quadrantIndex / 2) * QUADRANT_SIZE;
+
+    SDL_Rect destRect = {
+            tileX * TILE_SIZE + dx,
+            tileY * TILE_SIZE + dy,
+            QUADRANT_SIZE,
+            QUADRANT_SIZE
+    };
+    SDL_RenderCopy(renderer, srcTexture, NULL, &destRect);
+
+    quadrantIndex++;
+    if (quadrantIndex >= 4) {
+        tileIndex++;
+        quadrantIndex = 0;
+    }
+    SDL_SetRenderTarget(renderer, oldTarget);
+    return destRect;
+}
+
+SDL_Rect allocate_32x32(SDL_Texture *srcTexture, SDL_Renderer *renderer) {
+    SDL_Texture * oldTarget = SDL_GetRenderTarget(renderer);
+    SDL_SetRenderTarget(renderer, atlasTexture);
+    // If we’re not at the start of a tile, skip to the next clean one
+    if (quadrantIndex != 0) {
+        tileIndex++;
+        quadrantIndex = 0;
+    }
+
+    int tileX = tileIndex % ATLAS_TILES_PER_ROW;
+    int tileY = tileIndex / ATLAS_TILES_PER_ROW;
+
+    SDL_Rect destRect = {
+            tileX * TILE_SIZE,
+            tileY * TILE_SIZE,
+            TILE_SIZE,
+            TILE_SIZE
+    };
+    SDL_RenderCopy(renderer, srcTexture, NULL, &destRect);
+
+    tileIndex++; // Move to next tile
+    // quadrantIndex stays 0 — new tile is fresh
+    SDL_SetRenderTarget(renderer, oldTarget);
+    return destRect;
+}
+
+void initAtlas(SDL_Renderer *renderer) {
+
+// Clear atlas with transparent
+    SDL_SetRenderTarget(renderer, atlasTexture);
+    SDL_SetRenderDrawColor(renderer, 0, 0, 0, 0);
+    SDL_RenderClear(renderer);
+
+
+    atlasTexture = SDL_CreateTexture(renderer,
+                                     SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_TARGET,
+                                     ATLAS_SIZE, ATLAS_SIZE);
+}