diff --git a/src/Graphics_NDS.c b/src/Graphics_NDS.c
index 002e3d4c2..16790b632 100644
--- a/src/Graphics_NDS.c
+++ b/src/Graphics_NDS.c
@@ -25,14 +25,14 @@ void Gfx_Create(void) {
     glAlphaFunc(7);
 
     glClearDepth(GL_MAX_DEPTH);
-    glViewport(0, 0, 255, 191);
+    Gfx_SetViewport(0, 0, 256, 192);
     
     vramSetBankA(VRAM_A_TEXTURE);
     vramSetBankB(VRAM_B_TEXTURE);
     vramSetBankC(VRAM_C_TEXTURE);
     vramSetBankD(VRAM_D_TEXTURE);
     
-    glPolyFmt(POLY_ALPHA(31) | POLY_CULL_NONE);
+    Gfx_SetFaceCulling(false);
 }
 
 cc_bool Gfx_TryRestoreContext(void) {
@@ -67,7 +67,11 @@ void Gfx_SetVSync(cc_bool vsync) {
 void Gfx_OnWindowResize(void) { 
 }
 
-void Gfx_SetViewport(int x, int y, int w, int h) { }
+void Gfx_SetViewport(int x, int y, int w, int h) {
+	int x2 = x + w - 1, y2 = y + h - 1;
+	GFX_VIEWPORT = x | (y << 8) | (x2 << 16) | (y2 << 24);
+}
+
 void Gfx_SetScissor (int x, int y, int w, int h) { }
 
 void Gfx_BeginFrame(void) {
diff --git a/src/Picking.h b/src/Picking.h
index 6aa544a58..280a29fb0 100644
--- a/src/Picking.h
+++ b/src/Picking.h
@@ -18,7 +18,7 @@ http://www.devmaster.net/articles/raytracing_series/A%20faster%20voxel%20travers
 */
 struct RayTracer {
 	IVec3 pos;    /* Coordinates of block within world */
-	Vec3 origin, dir, invDir;
+	Vec3 origin, dir;
 	Vec3 Min, Max; /* Min/max coords of block's bounding box. */
 	BlockID block;
 	IVec3 step;
@@ -28,6 +28,7 @@ struct RayTracer {
 	IVec3 translatedPos; /* Coords of the neighbouring block that is closest to the player */
 	cc_bool valid;       /* Whether the ray tracer actually intersected with a block */
 	Face closest;        /* Face of the intersected block that is closet to the player */
+	Vec3 invDir;
 };
 
 /* Marks the given ray tracer as having no result. */