Setup working double buffering example

2 files changed, 51 insertions, 32 deletions

diff --git a/src/main.c b/src/main.c
index a52ad7c..c6f3c49 100644
--- a/src/main.c
+++ b/src/main.c
@@ -119,32 +119,42 @@ int main(void) {
     // Register interrupts.
     irq_init();
     irs_set(IRQ_VBLANK, irs_stub);
-    flip_buffer();
 
+    // draw_filled_rect(0, 0, 7, 7, 1);
+    // flip_buffer();
+    // draw_filled_rect(0, 0, 7, 7, 2);
+    // draw_filled_rect(8, 0, 15, 7, 3);
+    // BG_H_SCROLL_0 = 240;
+    // BG_H_SCROLL_0 = 240;
+    // BG_H_SCROLL_1 = 0;
     // Main loop.
     PROF_INIT();
     int x = 0;
     int inc = 1;
     while (true) {
         bios_vblank_wait();
+        flip_buffer();
 
         PROF(test_clear(), test_clear_cycles);
         // PROF(test_lines(), test_lines_cycles);
+
+        // ANIMATION EXAMPLE
         draw_rect(0 + x, 0, 100 + x, 100, 2);
         x += inc;
         if (x >= 50) {
-            inc = -8;
+            inc = -1;
         } else if (x <= 0) {
-            inc = 8;
+            inc = 1;
         }
+
         // draw_rect(50, 10, 200, 110, 1);
-        // PROF(test_rect(), test_rect_cycles);
+        PROF(test_rect(), test_rect_cycles);
         // PROF(test_fill_rect(), test_fill_rect_cycles);
         // PROF(test_chr(), test_chr_cycles);
         // PROF(test_icn(), test_icn_cycles);
         // draw_filled_rect(0, 0, 140, 60, 0);
         // PROF_SHOW();
-        PROF(flip_buffer(), flip_cycles);
+        // PROF(flip_buffer(), flip_cycles);
     }
 
     return 0;
diff --git a/src/renderer_m0.c b/src/renderer_m0.c
index b0d4a6e..b187903 100644
--- a/src/renderer_m0.c
+++ b/src/renderer_m0.c
@@ -29,10 +29,10 @@
 #define CB_1 1
 // NOTE: CB_2 could be at the end of 2 (0x0600:8000) since we only need a clear
 // color tile. Testing at 3 for now.
-#define CB_2 3
+// #define CB_2 3
 #define SB_0 20
-#define SB_1 21
-#define SB_2 23
+#define SB_1 22
+// #define SB_2 23
 
 // Available storage for other memory.
 // #define FG_PIXELS ((u32*)(MEM_VRAM + KB(44)))
@@ -56,7 +56,7 @@
 
 // Keep track of which tiles need to be copied to the frontbuffer.
 static u32 dirty_tiles[21] = {0};
-static u32 *backbuf = BUF_1;
+static u32 *backbuf = BUF_0;
 
 // Boundchecks can be disable at compile time but this will not always improve
 // the performance and can in fact make it worse. It is possible that this is
@@ -75,6 +75,7 @@ static u32 *backbuf = BUF_1;
 
 IWRAM_CODE
 void screen_fill(u8 clr)  {
+    // TODO: revise this with updated renderer.
 #if 1
     u32 *dst = backbuf;
     for(int i = 0; i < KB(20) / 4; i++) {
@@ -445,12 +446,16 @@ void
 flip_buffer(void) {
     if (backbuf == BUF_0) {
         backbuf = BUF_1;
-        BG_CTRL(0) = BG_CHARBLOCK(CB_0) | BG_SCREENBLOCK(SB_0) | BG_PRIORITY(0);
-        BG_CTRL(1) = BG_CHARBLOCK(CB_1) | BG_SCREENBLOCK(SB_1) | BG_PRIORITY(2);
+        BG_H_SCROLL_0 = 0;
+        BG_H_SCROLL_1 = 240;
+        BG_CTRL(0) = BG_CHARBLOCK(CB_0) | BG_SCREENBLOCK(SB_0) | BG_PRIORITY(0) | BG_SIZE(1);
+        BG_CTRL(1) = BG_CHARBLOCK(CB_1) | BG_SCREENBLOCK(SB_1) | BG_PRIORITY(2) | BG_SIZE(1);
     } else {
         backbuf = BUF_0;
-        BG_CTRL(0) = BG_CHARBLOCK(CB_0) | BG_SCREENBLOCK(SB_0) | BG_PRIORITY(2);
-        BG_CTRL(1) = BG_CHARBLOCK(CB_1) | BG_SCREENBLOCK(SB_1) | BG_PRIORITY(0);
+        BG_H_SCROLL_0 = 240;
+        BG_H_SCROLL_1 = 0;
+        BG_CTRL(0) = BG_CHARBLOCK(CB_0) | BG_SCREENBLOCK(SB_0) | BG_PRIORITY(2) | BG_SIZE(1);
+        BG_CTRL(1) = BG_CHARBLOCK(CB_1) | BG_SCREENBLOCK(SB_1) | BG_PRIORITY(0) | BG_SIZE(1);
     }
     // TODO: Copying all tiles for now. Study if it's better to use dirty_tiles
     // or dirty_lines.
@@ -616,7 +621,7 @@ txt_drawc(char c, size_t x, size_t y, u8 clr) {
 void
 renderer_init(void) {
     // Initialize display mode and bg palette.
-    DISP_CTRL = DISP_MODE_0 | DISP_BG_0 | DISP_BG_1 | DISP_BG_2 | DISP_OBJ;
+    DISP_CTRL = DISP_MODE_0 | DISP_BG_0 | DISP_BG_1;
     // DISP_CTRL = DISP_MODE_0 | DISP_BG_0 | DISP_BG_1 | DISP_OBJ;
     // TODO: black/grey background to block font/back buffers?
 
@@ -624,34 +629,38 @@ renderer_init(void) {
     dma_fill(MEM_VRAM, 0, KB(96), 3);
 
     // Initialize backgrounds.
-    BG_CTRL(0) = BG_CHARBLOCK(CB_0) | BG_SCREENBLOCK(SB_0) | BG_PRIORITY(0);
-    BG_CTRL(2) = BG_CHARBLOCK(CB_2) | BG_SCREENBLOCK(SB_2) | BG_PRIORITY(1);
-    BG_CTRL(1) = BG_CHARBLOCK(CB_1) | BG_SCREENBLOCK(SB_1) | BG_PRIORITY(2);
+    BG_CTRL(0) = BG_CHARBLOCK(CB_0) | BG_SCREENBLOCK(SB_0) | BG_PRIORITY(0) | BG_SIZE(1);
+    BG_CTRL(1) = BG_CHARBLOCK(CB_1) | BG_SCREENBLOCK(SB_1) | BG_PRIORITY(1) | BG_SIZE(1);
 
     // Initialize background memory map for frontbuffer.
     // for (size_t i = 0; i < 32 * 20; ++i) {
     //     TILE_MAP[i] = i;
     // }
     u16 *mem_map_fg = SCREENBLOCK_MEM[SB_0];
+    u16 *mem_map_fg_blank = SCREENBLOCK_MEM[SB_0 + 1];
     u16 *mem_map_bg = SCREENBLOCK_MEM[SB_1];
-    u16 *mem_map_clr = SCREENBLOCK_MEM[SB_2];
-    size_t k = 0;
-    for (size_t i = 0; i < 32 * 20; ++i, ++k) {
-        mem_map_fg[i] = k;
-        mem_map_bg[i] = k + 32 * 4;
-        mem_map_clr[i] = 0;
+    u16 *mem_map_bg_blank = SCREENBLOCK_MEM[SB_1 + 1];
+    for (size_t i = 0; i < 32 * 20; ++i) {
+        mem_map_fg[i] = i;
+        mem_map_fg_blank[i] = 32 * 20 - 1;
+        mem_map_bg[i] = i + 32 * 4;
+        mem_map_bg_blank[i] = 32 * 20 - 1;
     }
 
+    // Setup initial background state.
+    BG_H_SCROLL_0 = 240;
+    BG_H_SCROLL_1 = 0;
+
     // FIXME: clean this up.
-    u32 *clr_tile =((u32*)(MEM_VRAM) + 0xC000 / 4);
-    clr_tile[0] = 0x22222222;
-    clr_tile[1] = 0x22222222;
-    clr_tile[2] = 0x22222222;
-    clr_tile[3] = 0x22222222;
-    clr_tile[4] = 0x22222222;
-    clr_tile[5] = 0x22222222;
-    clr_tile[6] = 0x22222222;
-    clr_tile[7] = 0x22222222;
+    // u32 *clr_tile =((u32*)(MEM_VRAM) + 0xC000 / 4);
+    // clr_tile[0] = 0x22222222;
+    // clr_tile[1] = 0x22222222;
+    // clr_tile[2] = 0x22222222;
+    // clr_tile[3] = 0x22222222;
+    // clr_tile[4] = 0x22222222;
+    // clr_tile[5] = 0x22222222;
+    // clr_tile[6] = 0x22222222;
+    // clr_tile[7] = 0x22222222;
 
     // Initialize default palette.
     PAL_BUFFER_BG[0] = COLOR_BLACK;