@@ -38,7 +38,7 @@ static Uint8 font[][8] = {

 	{0x00, 0x7c, 0x82, 0x80, 0xf0, 0x80, 0x80, 0x80}};

 void

-ppu_set_size(Ppu *p, Uint16 width, Uint16 height)

+ppu_resize(Ppu *p, Uint16 width, Uint16 height)

 {

 	Uint8 *pixels;

 	if(!(pixels = realloc(p->pixels, width * height / 2)))

@@ -49,11 +49,19 @@ ppu_set_size(Ppu *p, Uint16 width, Uint16 height)

 	p->height = height;

 }

+void

+ppu_clear(Ppu *p, Uint8 mask)

+{

+	Uint32 i, size = p->width * p->height / 2;

+	for(i = 0; i < size; ++i)

+		p->pixels[i] &= mask;

+}

+

 Uint8

 ppu_read(Ppu *p, Uint16 x, Uint16 y)

 {

 	if(x < p->width && y < p->height) {

-		Uint32 row = (x + y * p->width) / 0x2;

+		Uint32 row = (x + y * p->width) / 2;

 		Uint8 shift = !(x & 0x1) << 2;

 		Uint8 pix = p->pixels[row] >> shift;

 		if(pix & 0x0c)

@@ -67,7 +75,7 @@ void

 ppu_write(Ppu *p, Uint8 layer, Uint16 x, Uint16 y, Uint8 color)

 {

 	if(x < p->width && y < p->height) {

-		Uint32 row = (x + y * p->width) / 0x2;

+		Uint32 row = (x + y * p->width) / 2;

 		Uint8 shift = (!(x & 0x1) << 2) + (layer << 1);

 		Uint8 pix = p->pixels[row];

 		Uint8 mask = ~(0x3 << shift);

@@ -14,6 +14,10 @@ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 WITH REGARD TO THIS SOFTWARE.

 */

+#define CLEAR_BG 0xcc

+#define CLEAR_FG 0x33

+#define CLEAR_BOTH 0x00

+

 typedef unsigned char Uint8;

 typedef unsigned short Uint16;

 typedef unsigned int Uint32;

@@ -23,10 +27,10 @@ typedef struct Ppu {

 	Uint16 width, height;

 } Ppu;

-void ppu_set_size(Ppu *p, Uint16 width, Uint16 height);

+void ppu_resize(Ppu *p, Uint16 width, Uint16 height);

+void ppu_clear(Ppu *p, Uint8 layer);

 Uint8 ppu_read(Ppu *p, Uint16 x, Uint16 y);

 void ppu_write(Ppu *p, Uint8 layer, Uint16 x, Uint16 y, Uint8 color);

-void ppu_frame(Ppu *p);

 void ppu_1bpp(Ppu *p, Uint8 layer, Uint16 x, Uint16 y, Uint8 *sprite, Uint8 color, Uint8 flipx, Uint8 flipy);

 void ppu_2bpp(Ppu *p, Uint8 layer, Uint16 x, Uint16 y, Uint8 *sprite, Uint8 color, Uint8 flipx, Uint8 flipy);

 void ppu_debug(Ppu *p, Uint8 *stack, Uint8 wptr, Uint8 rptr, Uint8 *memory);

@@ -127,7 +127,7 @@ set_zoom(Uint8 scale)

 static int

 set_size(Uint16 width, Uint16 height, int is_resize)

 {

-	ppu_set_size(&ppu, width, height);

+	ppu_resize(&ppu, width, height);

 	gRect.x = PAD;

 	gRect.y = PAD;

 	gRect.w = ppu.width;

@@ -487,7 +487,7 @@ doctrl(Uxn *u, SDL_Event *event, int z)

 	case SDLK_LEFT: flag = 0x40; break;

 	case SDLK_RIGHT: flag = 0x80; break;

 	case SDLK_F1: if(z) set_zoom(zoom > 2 ? 1 : zoom + 1); break;

-	case SDLK_F2: if(z) devsystem->dat[0xe] = !devsystem->dat[0xe]; break;

+	case SDLK_F2: if(z) devsystem->dat[0xe] = !devsystem->dat[0xe]; ppu_clear(&ppu, CLEAR_FG); break;

 	case SDLK_F3: if(z) capture_screen(); break;

 	case SDLK_AC_BACK:

 	case SDLK_F4: if(z) restart(u); break;