3 files changed, 32 insertions, 32 deletions

diff --git a/src/common.h b/src/common.h
index e62c78c..1fbfa4c 100644
--- a/src/common.h
+++ b/src/common.h
@@ -419,12 +419,16 @@ dma_transfer_fill(void *dst, volatile u32 src, u32 count, int channel, u32 optio
 inline void
 dma_copy(void *dst, const void *src, u32 size, int channel) {
     dma_transfer_copy(dst, src, size / 4, channel, DMA_CHUNK_32 | DMA_ENABLE);
+    // Stall for 2 cycles in case we call this function more than once.
+    asm("nop"); asm("nop");
 }
 
 // Fill the dst location with the word set at src.
 inline void
 dma_fill(void *dst, vu32 src, u32 size, int channel) {
     dma_transfer_fill(dst, src, size / 4, channel, DMA_CHUNK_32 | DMA_ENABLE);
+    // Stall for 2 cycles in case we call this function more than once.
+    asm("nop"); asm("nop");
 }
 
 //
diff --git a/src/ppu.c b/src/ppu.c
index d68ab8f..bc6f503 100644
--- a/src/ppu.c
+++ b/src/ppu.c
@@ -16,6 +16,7 @@ WITH REGARD TO THIS SOFTWARE.
 */
 
 #define NEW_PPU 1
+#define FLIPBUF_DMA 1
 
 #define FG_FRONT  ((u32*)(MEM_VRAM))
 #define BG_FRONT  ((u32*)(MEM_VRAM + KB(20)))
@@ -722,32 +723,33 @@ putfontchar(u32 *layer, u16 tile_x, u16 tile_y, u8 ch, u8 color) {
 IWRAM_CODE
 void
 flipbuf() {
-    // Copy the fg and bg layers fully with the DMA.
-    dma_copy((u32*)FG_FRONT, (u32*)FG_BACK, KB(40), 3);
-    // dma_sync_copy((u32*)FG_FRONT, (u32*)FG_BACK, KB(40));
-    //
-    // TODO: dma the dirty lines instead of per tile copying.
-    // dma_copy((u32*)BG_FRONT, (u32*)BG_BACK, KB(20), 3);
-    // dma_sync_copy((u32*)FG_FRONT, (u32*)FG_BACK, KB(20));
-    // dma_sync_copy((u32*)BG_FRONT, (u32*)BG_BACK, KB(20));
-    // Tile *mem_fg = FG_FRONT;
-    // Tile *mem_bg = BG_FRONT;
-    // for (size_t j = 0; j < 20; ++j) {
-    //     if (dirty_tiles[j] == 0) {
-    //         continue;
-    //     }
-
-    //     // size_t k = 1;
-    //     // for (size_t i = 0; i < 30; ++i, k <<= 1) {
-    //     //     if (dirty_tiles[j] & k) {
-    //     //         Tile *tile_fg = FG_BACK;
-    //     //         Tile *tile_bg = BG_BACK;
-    //     //         mem_fg[i + j * 32] = tile_fg[i + j * 32];
-    //     //         mem_bg[i + j * 32] = tile_bg[i + j * 32];
-    //     //     }
-    //     // }
-    //     dirty_tiles[j] = 0;
-    // }
+    u32 *fg_back = FG_BACK;
+    u32 *bg_back = BG_BACK;
+    u32 *bg_front = BG_FRONT;
+    u32 *fg_front = FG_FRONT;
+    for (size_t j = 0; j < 20; ++j) {
+        if (dirty_tiles[j] == 0) {
+            continue;
+        }
+#if FLIPBUF_DMA == 1
+        u32 offset = j * 32 * 8;
+        dma_copy(fg_front + offset, fg_back + offset, 32 * 8 * 4, 3);
+        dma_copy(bg_front + offset, bg_back + offset, 32 * 8 * 4, 3);
+#else
+        size_t k = 1;
+        for (size_t i = 0; i < 30; ++i, k <<= 1) {
+            if (dirty_tiles[j] & k) {
+                Tile *mem_fg = FG_FRONT;
+                Tile *mem_bg = BG_FRONT;
+                Tile *tile_fg = FG_BACK;
+                Tile *tile_bg = BG_BACK;
+                mem_fg[i + j * 32] = tile_fg[i + j * 32];
+                mem_bg[i + j * 32] = tile_bg[i + j * 32];
+            }
+        }
+#endif
+        dirty_tiles[j] = 0;
+    }
 }
 
 typedef struct KeyboardChar {
diff --git a/src/ppu.h b/src/ppu.h
index f12e1a7..bd9120c 100644
--- a/src/ppu.h
+++ b/src/ppu.h
@@ -17,12 +17,6 @@ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 WITH REGARD TO THIS SOFTWARE.
 */
 
-typedef struct Ppu {
-        u32 *bg, *fg;
-        u16 hor, ver, width, height;
-} Ppu;
-
-int initppu(Ppu *p, u8 hor, u8 ver);
 void putcolors(u8 *addr);
 void ppu_pixel(u32 *layer, u16 x, u16 y, u8 color);
 void ppu_1bpp(u32 *layer, u16 x, u16 y, u8 *sprite, u8 color, u8 flipx, u8 flipy);