1 files changed, 91 insertions, 0 deletions
diff --git a/src/threading.cpp b/src/threading.cpp
new file mode 100644
index 0000000..5a42ea7
--- /dev/null
+++ b/src/threading.cpp
@@ -0,0 +1,91 @@
+static void
+RenderLayers(render_entry Entry);
+
+static bool32
+CheckQueue(uint16 Index)
+{
+    bool32 Result = 0;
+    uint32 Q = SDL_AtomicGet(&QueuedEntries);
+    uint32 C = SDL_AtomicGet(&CurrentEntry);
+    if (Q > C)
+    {
+        if (SDL_AtomicCAS(&CurrentEntry, C, C + 1)) {
+            // printf("C: %i START: F%i Thread %i, region X%i Y%i\n", C, Entry->FrameNumber, Index, Entry->RenderRegion.Min.x, Entry->RenderRegion.Min.y);
+            RenderLayers(Entries[C]);
+            // printf("END: F%i Thread %i, region X%i Y%i\n", Entry->FrameNumber, Index, Entry->RenderRegion.Min.x, Entry->RenderRegion.Min.y);
+            SDL_AtomicAdd(&CompletedEntries, 1);
+            Result = 1;
+        }
+    }
+    return Result;
+}
+
+static int
+TestThread(void *ptr)
+{
+    uint16 Index = *(uint16 *)ptr;
+    for(;;)
+    {
+        if (!CheckQueue(Index))
+        {
+            SDL_SemWait(Semaphore);
+        }
+    }
+}
+
+static bool32
+Threading_IsActive(render_type RenderType)
+{
+    int32 Threads = 16;
+    if (RenderType == render_type_brush)
+        Threads = 4;
+    uint32 C = SDL_AtomicGet(&CompletedEntries);
+    Assert(C < Threads + 1);
+    return (C == Threads) ? false : true;
+}
+
+static void
+Threading_BitmapOp(void *Data, void *OutputBuffer, render_type RenderType, rectangle InitialRenderRegion)
+{
+    int i = (RenderType != render_type_brush) ? 4 : 2;
+    uint16 TileWidth = (InitialRenderRegion.Max.x - InitialRenderRegion.Min.x) / i;
+    uint16 TileHeight = (InitialRenderRegion.Max.y - InitialRenderRegion.Min.y) / i;
+
+    SDL_AtomicSet(&QueuedEntries, 0);
+    SDL_AtomicSet(&CurrentEntry, 0);
+    SDL_AtomicSet(&CompletedEntries, 0);
+
+    for (int y = 0; y < i; y++) {
+        for (int x = 0; x < i; x++) {
+            // if ((x == 0 && y == 0)|| RenderType != render_type_brush) {
+
+            rectangle RenderRegion = { TileWidth*x, TileHeight*y,
+                                       TileWidth + TileWidth*x, TileHeight + TileHeight*y };
+
+            if (RenderType != render_type_main) {
+                RenderRegion.Min.x += InitialRenderRegion.Min.x;
+                RenderRegion.Min.y += InitialRenderRegion.Min.y;
+                RenderRegion.Max.x += InitialRenderRegion.Min.x;
+                RenderRegion.Max.y += InitialRenderRegion.Min.y;
+            }
+
+            if (RenderRegion.Max.x > InitialRenderRegion.Max.x)
+                RenderRegion.Max.x = InitialRenderRegion.Max.x;
+            if (RenderRegion.Max.y > InitialRenderRegion.Max.y)
+                RenderRegion.Max.y = InitialRenderRegion.Max.y;
+
+            if (x == i-1)
+                RenderRegion.Max.x = InitialRenderRegion.Max.x;
+            if (y == i-1)
+                RenderRegion.Max.y = InitialRenderRegion.Max.y;
+
+            render_entry Entry = { Data, OutputBuffer, RenderType, RenderRegion };
+
+            uint32 Q = SDL_AtomicGet(&QueuedEntries);
+            *(Entries + Q) = Entry;
+            SDL_AtomicAdd(&QueuedEntries, 1);
+            SDL_SemPost(Semaphore);
+            // }
+        }
+    }
+}