diff --git a/nasu.c b/nasu.c
index 331826f..62a54d8 100644
--- a/nasu.c
+++ b/nasu.c
@@ -14,14 +14,9 @@
 #define SZ (HOR * VER * 16)
 
 typedef struct Brush {
-	int x, y;
-	int px, py;
-	int mode;
-	int size;
-	int color;
-	int down;
-	int edit;
-	int erase;
+	int x, y, px, py;
+	int mode, size, color;
+	int down, edit, erase;
 } Brush;
 
 char *modes[] = {
@@ -34,7 +29,6 @@ char *modes[] = {
 	"exes",
 	"fixe"};
 
-unsigned char chrbuf[SZ];
 int colors[] = {color1, color2, color3, color4, color0};
 int WIDTH = 8 * HOR + PAD * 2;
 int HEIGHT = 8 * VER + PAD * 2;
@@ -43,7 +37,8 @@ int GUIDES = 0;
 SDL_Window *gWindow = NULL;
 SDL_Renderer *gRenderer = NULL;
 SDL_Texture *gTexture = NULL;
-uint32_t *pixels;
+unsigned char chrbuf[SZ];
+Uint32 *pixels;
 
 /* helpers */
 
@@ -200,23 +195,30 @@ line(int ax, int ay, int bx, int by, int color)
 /* draw */
 
 void
-draw(uint32_t *dst)
+drawtile(Uint32 *dst, int x, int y, int id)
 {
-	int b, i, j, id = 0;
-	for(b = 0; b < SZ; b += 16)
-		for(i = 0; i < 8; i++)
-			for(j = 7; j >= 0; j--) {
-				int ch1 = chrbuf[b + i];
-				int ch2 = chrbuf[b + i + 8];
-				int color = ((ch1 >> j) & 0x1) + (((ch2 >> j) & 0x1) << 1);
-				int ti = id / 64;
-				int odd = (ti + (ti / HOR + 2)) % 2 == 0;
-				int px = (ti / (HOR * VER)) * (8 * HOR) + (ti % HOR) * 8 + (id % 8);
-				int py = ((ti / HOR) * 8) + ((id % 64) / 8);
-				dst[(py + PAD) * WIDTH + (px + PAD)] = colors[GUIDES && odd && color == 0 ? 4 : color];
-				id++;
-			}
-	SDL_UpdateTexture(gTexture, NULL, dst, WIDTH * sizeof(uint32_t));
+	int v, h, offset = id * 16, sz = WIDTH * HEIGHT;
+	for(v = 0; v < 8; v++)
+		for(h = 0; h < 8; h++) {
+			int px = (x * 8) + (8 - h);
+			int py = (y * 8) + v;
+			int ch1 = chrbuf[offset + v];
+			int ch2 = chrbuf[offset + v + 8];
+			int clr = ((ch1 >> h) & 0x1) + (((ch2 >> h) & 0x1) << 1);
+			int key = (py + PAD) * WIDTH + (px + PAD);
+			if(key >= 0 && key <= sz - 1)
+				dst[key] = colors[clr];
+		}
+}
+
+void
+draw(Uint32 *dst)
+{
+	int x, y;
+	for(y = 0; y < VER; ++y)
+		for(x = 0; x < HOR; ++x)
+			drawtile(dst, x, y, x + y * HOR);
+	SDL_UpdateTexture(gTexture, NULL, dst, WIDTH * sizeof(Uint32));
 	SDL_RenderClear(gRenderer);
 	SDL_RenderCopy(gRenderer, gTexture, NULL, NULL);
 	SDL_RenderPresent(gRenderer);
@@ -329,8 +331,9 @@ domouse(SDL_Event *event, Brush *b)
 		update(b);
 		break;
 	case SDL_MOUSEBUTTONDOWN:
-		if(event->button.button == SDL_BUTTON_LEFT)
+		if(event->button.button == SDL_BUTTON_LEFT) {
 			b->down = 1;
+		}
 		if(event->button.button == SDL_BUTTON_RIGHT)
 			b->erase = 1;
 		if(event->button.button == SDL_BUTTON_MIDDLE) {
@@ -344,6 +347,11 @@ domouse(SDL_Event *event, Brush *b)
 		}
 		b->px = (event->motion.x - (PAD * ZOOM)) / ZOOM;
 		b->py = (event->motion.y - (PAD * ZOOM)) / ZOOM;
+		if(b->down) {
+			putchr(b->px, b->py, b->color);
+			draw(pixels);
+		}
+		break;
 	case SDL_MOUSEMOTION:
 		if(b->down) {
 			b->x = (event->motion.x - (PAD * ZOOM)) / ZOOM;
@@ -420,7 +428,7 @@ init(void)
 		HEIGHT);
 	if(gTexture == NULL)
 		return error("Texture", SDL_GetError());
-	pixels = (uint32_t *)malloc(WIDTH * HEIGHT * sizeof(uint32_t));
+	pixels = (Uint32 *)malloc(WIDTH * HEIGHT * sizeof(Uint32));
 	if(pixels == NULL)
 		return error("Pixels", "Failed to allocate memory");
 	for(i = 0; i < HEIGHT; i++)