3 files changed, 169 insertions, 82 deletions

diff --git a/src/main.c b/src/main.c
index 4b2b2d6..0e56897 100644
--- a/src/main.c
+++ b/src/main.c
@@ -136,11 +136,11 @@ screen_talk(Device *d, u8 b0, u8 w) {
         u8 *layer = d->dat[0xe] >> 4 & 0x1 ? ppu.fg : ppu.bg;
         u8 mode = d->dat[0xe] >> 5;
         if(!mode) {
-            putpixel(layer, x, y, d->dat[0xe] & 0x3);
+            ppu_pixel(layer, x, y, d->dat[0xe] & 0x3);
         } else if(mode-- & 0x1) {
-            puticn(layer, x, y, addr, d->dat[0xe] & 0xf, mode & 0x2, mode & 0x4);
+            ppu_1bpp(layer, x, y, addr, d->dat[0xe] & 0xf, mode & 0x2, mode & 0x4);
         } else {
-            putchr(layer, x, y, addr, d->dat[0xe] & 0xf, mode & 0x2, mode & 0x4);
+            ppu_2bpp(layer, x, y, addr, d->dat[0xe] & 0xf, mode & 0x2, mode & 0x4);
         }
     }
 }
diff --git a/src/ppu.c b/src/ppu.c
index f626604..018555f 100644
--- a/src/ppu.c
+++ b/src/ppu.c
@@ -25,7 +25,7 @@ WITH REGARD TO THIS SOFTWARE.
 // Keyboard.
 #define SPRITE_START_IDX 640
 
-static u32 unpack_icon_lut[256] = {
+static u32 lut_2bpp[256] = {
     0x00000000, 0x00000001, 0x00000010, 0x00000011, 0x00000100,
     0x00000101, 0x00000110, 0x00000111, 0x00001000, 0x00001001,
     0x00001010, 0x00001011, 0x00001100, 0x00001101, 0x00001110,
@@ -80,7 +80,7 @@ static u32 unpack_icon_lut[256] = {
     0x11111111
 };
 
-static u32 unpack_icon_lut_flipx[256] = {
+static u32 lut2bpp_flipx[256] = {
     0x00000000, 0x10000000, 0x01000000, 0x11000000, 0x00100000,
     0x10100000, 0x01100000, 0x11100000, 0x00010000, 0x10010000,
     0x01010000, 0x11010000, 0x00110000, 0x10110000, 0x01110000,
@@ -135,6 +135,14 @@ static u32 unpack_icon_lut_flipx[256] = {
     0x11111111
 };
 
+static u8 blending[5][16] = {
+    {0, 0, 0, 0, 1, 0, 1, 1, 2, 2, 0, 2, 3, 3, 3, 0},
+    {0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3},
+    {1, 2, 3, 1, 1, 2, 3, 1, 1, 2, 3, 1, 1, 2, 3, 1},
+    {2, 3, 1, 2, 2, 3, 1, 2, 2, 3, 1, 2, 2, 3, 1, 2},
+    {1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0}
+};
+
 static u32 dirty_tiles[21] = {0};
 
 void
@@ -160,7 +168,7 @@ putcolors(u8 *addr) {
 
 IWRAM_CODE
 void
-putpixel(u32 *layer, u16 x, u16 y, u8 color) {
+ppu_pixel(u32 *layer, u16 x, u16 y, u8 color) {
     if (x >= SCREEN_WIDTH || y >= SCREEN_HEIGHT) return;
     size_t tile_x = x / 8;
     size_t tile_y = y / 8;
@@ -174,106 +182,185 @@ putpixel(u32 *layer, u16 x, u16 y, u8 color) {
 
 IWRAM_CODE
 void
-puticn(u32 *layer, u16 x, u16 y, u8 *sprite, u8 color, u8 flipx, u8 flipy) {
-        u8 sprline;
-        u16 v;
-        u32 dirtyflag = (1 << (x >> 3)) | (1 << ((x + 7) >> 3));
-
-        u32 layerpos = ((y & 7) + (((x >> 3) + (y >> 3) * 32) * 8));
-        u32 *layerptr = &layer[layerpos];
-        u32 shift = (x & 7) << 2;
-        u32 *lut_expand = flipx ? unpack_icon_lut : unpack_icon_lut_flipx;
+ppu_1bpp(u32 *layer, u16 x, u16 y, u8 *sprite, u8 color, u8 flipx, u8 flipy) {
+    u8 sprline;
+    u16 v;
+    u32 dirtyflag = (1 << (x >> 3)) | (1 << ((x + 7) >> 3));
 
-        if (flipy) flipy = 7;
+    u32 layerpos = ((y & 7) + (((x >> 3) + (y >> 3) * 32) * 8));
+    u32 *layerptr = &layer[layerpos];
+    u32 shift = (x & 7) << 2;
+    u32 *lut_expand = flipx ? lut_2bpp : lut2bpp_flipx;
 
-        if (x >= SCREEN_WIDTH || y >= SCREEN_HEIGHT) return;
+    if (flipy) flipy = 7;
 
-        if (color != 0x05 && color != 0x0a && color != 0x0f) {
-                u64 mask = ~((u64)0xFFFFFFFF << shift);
+    if (x >= SCREEN_WIDTH || y >= SCREEN_HEIGHT) return;
 
-                for (v = 0; v < 8; v++, layerptr++) {
-                        if ((y + v) >= SCREEN_HEIGHT) break;
+    if (blending[4][color]) {
+        u64 mask = ~((u64)0xFFFFFFFF << shift);
 
-                        sprline = sprite[v ^ flipy];
-                        u64 data = (u64)(lut_expand[sprline] * (color & 3)) << shift;
-                        data |= (u64)(lut_expand[sprline ^ 0xFF] * (color >> 2)) << shift;
+        for (v = 0; v < 8; v++, layerptr++) {
+            if ((y + v) >= SCREEN_HEIGHT) break;
 
-                        layerptr[0] = (layerptr[0] & mask) | data;
-                        layerptr[8] = (layerptr[8] & (mask >> 32)) | (data >> 32);
+            sprline = sprite[v ^ flipy];
+            u64 data = (u64)(lut_expand[sprline] * (color & 3)) << shift;
+            data |= (u64)(lut_expand[sprline ^ 0xFF] * (color >> 2)) << shift;
 
-                        if (((y + v) & 7) == 7) layerptr += (32 - 1) * 8;
-                }
-        } else {
-                for (v = 0; v < 8; v++, layerptr++) {
-                        if ((y + v) >= SCREEN_HEIGHT) break;
+            layerptr[0] = (layerptr[0] & mask) | data;
+            layerptr[8] = (layerptr[8] & (mask >> 32)) | (data >> 32);
 
-                        sprline = sprite[v ^ flipy];
-                        u64 mask = ~((u64)(lut_expand[sprline] * 0xF) << shift);
-                        u64 data = (u64)(lut_expand[sprline] * (color & 3)) << shift;
+            if (((y + v) & 7) == 7) layerptr += (32 - 1) * 8;
+        }
+    } else {
+        for (v = 0; v < 8; v++, layerptr++) {
+            if ((y + v) >= SCREEN_HEIGHT) break;
 
-                        layerptr[0] = (layerptr[0] & mask) | data;
-                        layerptr[8] = (layerptr[8] & (mask >> 32)) | (data >> 32);
+            sprline = sprite[v ^ flipy];
+            u64 mask = ~((u64)(lut_expand[sprline] * 0xF) << shift);
+            u64 data = (u64)(lut_expand[sprline] * (color & 3)) << shift;
 
-                        if (((y + v) & 7) == 7) layerptr += (32 - 1) * 8;
-                }
-        }
+            layerptr[0] = (layerptr[0] & mask) | data;
+            layerptr[8] = (layerptr[8] & (mask >> 32)) | (data >> 32);
 
-        dirty_tiles[y >> 3] |= dirtyflag;
-        dirty_tiles[(y + 7) >> 3] |= dirtyflag;
-}
+            if (((y + v) & 7) == 7) layerptr += (32 - 1) * 8;
+        }
+    }
 
-IWRAM_CODE
-void
-putfontchar(u32 *layer, u16 tile_x, u16 tile_y, u8 ch, u8 color) {
-        u32 pos = (tile_x + tile_y * 32) * 8;
-        u32 *tile_data = &layer[pos];
-        u32 *font_data = &FONT_DATA[8 * ch];
-        for (size_t i = 0; i < 8; ++i) {
-            tile_data[i] = font_data[i] * color;
-        }
-    dirty_tiles[tile_y] |= 1 << tile_x;
+    dirty_tiles[y >> 3] |= dirtyflag;
+    dirty_tiles[(y + 7) >> 3] |= dirtyflag;
 }
 
 IWRAM_CODE
 void
-putchr(u32 *layer, u16 x, u16 y, u8 *sprite, u8 color,
+ppu_2bpp(u32 *layer, u16 x, u16 y, u8 *sprite, u8 color,
         u8 flipx, u8 flipy) {
-        u8 sprline1, sprline2;
-        u16 v;
-        u32 dirtyflag = (1 << (x >> 3)) | (1 << ((x + 7) >> 3));
+    u8 sprline1, sprline2;
+    u8 xrightedge = x < ((32 - 1) * 8);
+    u16 v, h;
+    u32 dirtyflag = (1 << (x >> 3)) | (1 << ((x + 7) >> 3));
+
+    u32 layerpos = ((y & 7) + (((x >> 3) + (y >> 3) * 32) * 8));
+    u32 *layerptr = &layer[layerpos];
+    u32 shift = (x & 7) << 2;
+
+    if (flipy) flipy = 7;
+
+    if (x >= SCREEN_WIDTH || y >= SCREEN_HEIGHT) return;
+
+    if (color == 1) {
+        u32 *lut_expand = flipx ? lut_2bpp : lut2bpp_flipx;
+        u64 mask = ~((u64)0xFFFFFFFF << shift);
+
+        for (v = 0; v < 8; v++, layerptr++) {
+            if ((y + v) >= (24 * 8)) break;
 
-        u32 layerpos = ((y & 7) + (((x >> 3) + (y >> 3) * 32) * 8));
-        u32 *layerptr = &layer[layerpos];
-        u32 shift = (x & 7) << 2;
-        u32 *lut_expand = flipx ? unpack_icon_lut : unpack_icon_lut_flipx;
+            sprline1 = sprite[v ^ flipy];
+            sprline2 = sprite[(v ^ flipy) | 8];
 
-        if (flipy) flipy = 7;
+            u32 data32 = (lut_expand[sprline1]) | (lut_expand[sprline2] << 1);
+            u64 data = ((u64) (data32 & 0x33333333)) << shift;
 
-        if (x >= SCREEN_WIDTH || y >= SCREEN_HEIGHT) return;
+            layerptr[0] = (layerptr[0] & mask) | data;
+            if (xrightedge) layerptr[8] = (layerptr[8] & (mask >> 32)) | (data >> 32);
+
+            if (((y + v) & 7) == 7) layerptr += (32 - 1) * 8;
+        }
+    } else if (blending[4][color]) {
+        u64 mask = ~((u64)0xFFFFFFFF << shift);
 
-        u64 mask = ~((u64)0xFFFFFFFF << shift);
-        u32 colconst = (color >> 2) * 0x11111111;
+        for (v = 0; v < 8; v++, layerptr++) {
+            if ((y + v) >= (24 * 8)) break;
 
-        for (v = 0; v < 8; v++, layerptr++) {
-                if ((y + v) >= SCREEN_HEIGHT) break;
+            u8 ch1 = sprite[v ^ flipy];
+            u8 ch2 = sprite[(v ^ flipy) | 8];
+            u32 data32 = 0;
 
-                sprline1 = sprite[v ^ flipy];
-                sprline2 = sprite[(v ^ flipy) | 8];
+            if (!flipx) {
+                for (h = 0; h < 8; h++) {
+                    data32 <<= 4;
 
-                u32 data32 =
-                        (lut_expand[sprline1] * (color & 3))
-                        + (lut_expand[sprline2] * ((color & 1) << 1))
-                        + colconst;
-                u64 data = ((u64) (data32 & 0x33333333)) << shift;
+                    u8 ch = (ch1 & 1) | ((ch2 & 1) << 1);
+                    data32 |= blending[ch][color];
 
-                layerptr[0] = (layerptr[0] & mask) | data;
-                layerptr[8] = (layerptr[8] & (mask >> 32)) | (data >> 32);
+                    ch1 >>= 1; ch2 >>= 1;
+                }
+            } else {
+                for (h = 0; h < 8; h++) {
+                    data32 <<= 4;
 
-                if (((y + v) & 7) == 7) layerptr += (32 - 1) * 8;
-        }
+                    u8 ch = (ch1 >> 7) | ((ch2 >> 7) << 1);
+                    data32 |= blending[ch][color];
 
-        dirty_tiles[y >> 3] |= dirtyflag;
-        dirty_tiles[(y + 7) >> 3] |= dirtyflag;
+                    ch1 <<= 1; ch2 <<= 1;
+                }
+            }
+
+            u64 data = ((u64) (data32 & 0x33333333)) << shift;
+
+            layerptr[0] = (layerptr[0] & mask) | data;
+            if (xrightedge) layerptr[8] = (layerptr[8] & (mask >> 32)) | (data >> 32);
+
+            if (((y + v) & 7) == 7) layerptr += (32 - 1) * 8;
+        }
+    } else {
+        for (v = 0; v < 8; v++, layerptr++) {
+            if ((y + v) >= (24 * 8)) break;
+
+            u8 ch1 = sprite[v ^ flipy];
+            u8 ch2 = sprite[(v ^ flipy) | 8];
+            u32 data32 = 0;
+            u32 mask32 = 0;
+
+            if (!flipx) {
+                for (h = 0; h < 8; h++) {
+                    data32 <<= 4; mask32 <<= 4;
+
+                    if ((ch1 | ch2) & 1) {
+                        u8 ch = (ch1 & 1) | ((ch2 & 1) << 1);
+                        data32 |= blending[ch][color];
+                        mask32 |= 0xF;
+                    }
+
+                    ch1 >>= 1; ch2 >>= 1;
+                }
+            } else {
+                for (h = 0; h < 8; h++) {
+                    data32 <<= 4; mask32 <<= 4;
+
+                    if ((ch1 | ch2) & 128) {
+                        u8 ch = (ch1 >> 7) | ((ch2 >> 7) << 1);
+                        data32 |= blending[ch][color];
+                        mask32 |= 0xF;
+                    }
+
+                    ch1 <<= 1; ch2 <<= 1;
+                }
+            }
+
+            u64 data = ((u64) (data32 & 0x33333333)) << shift;
+            u64 mask = ~(((u64) (mask32 & 0x33333333)) << shift);
+
+            layerptr[0] = (layerptr[0] & mask) | data;
+            if (xrightedge) layerptr[8] = (layerptr[8] & (mask >> 32)) | (data >> 32);
+
+            if (((y + v) & 7) == 7) layerptr += (32 - 1) * 8;
+        }
+    }
+
+    dirty_tiles[y >> 3] |= dirtyflag;
+    dirty_tiles[(y + 7) >> 3] |= dirtyflag;
+}
+
+IWRAM_CODE
+void
+putfontchar(u32 *layer, u16 tile_x, u16 tile_y, u8 ch, u8 color) {
+    u32 pos = (tile_x + tile_y * 32) * 8;
+    u32 *tile_data = &layer[pos];
+    u32 *font_data = &FONT_DATA[8 * ch];
+    for (size_t i = 0; i < 8; ++i) {
+        tile_data[i] = font_data[i] * color;
+    }
+    dirty_tiles[tile_y] |= 1 << tile_x;
 }
 
 IWRAM_CODE
diff --git a/src/ppu.h b/src/ppu.h
index 0356b63..b5eb250 100644
--- a/src/ppu.h
+++ b/src/ppu.h
@@ -24,7 +24,7 @@ typedef struct Ppu {
 
 int initppu(Ppu *p, u8 hor, u8 ver, u8 pad);
 void putcolors(u8 *addr);
-void putpixel(u32 *layer, u16 x, u16 y, u8 color);
-void puticn(u32 *layer, u16 x, u16 y, u8 *sprite, u8 color, u8 flipx, u8 flipy);
-void putchr(u32 *layer, u16 x, u16 y, u8 *sprite, u8 color, u8 flipx, u8 flipy);
+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);
+void ppu_2bpp(u32 *layer, u16 x, u16 y, u8 *sprite, u8 color, u8 flipx, u8 flipy);
 #endif // UXNGBA_PPU_H