diff --git a/include/functions.h b/include/functions.h
index beb24655..273f13af 100644
--- a/include/functions.h
+++ b/include/functions.h
@@ -250,8 +250,6 @@ void particleEmitter_setParticleVelocityRange(ParticleEmitter *, f32, f32, f32,
 void func_802EFF50(ParticleEmitter *, f32);
 void particleEmitter_setRGB(ParticleEmitter *this, s32 arg1[3]);
 void particleEmitter_setSpawnInterval(ParticleEmitter *, f32);
-int  viewport_isPointOutsideFrustum_3f(f32, f32, f32);
-void viewport_adjustPointDistance(f32 [3], f32);
 OSContPad *func_8024F3F4(void);
 OSMesgQueue *pfsManager_getFrameReplyQ(void);
 
@@ -582,4 +580,53 @@ extern void miscFlag_set(enum misc_flag_e arg0);
 extern void miscFlag_clear(enum misc_flag_e arg0);
 extern void miscFlag_toggle(enum misc_flag_e arg0);
 
+extern void viewport_moveAlongZAxis(f32 offset);
+extern f32 viewport_getDistance(f32 arg0[3]);
+extern void viewport_getLookVector(f32 arg0[3]);
+extern void viewport_getPosition_vec3f(f32 arg0[3]);
+extern void viewport_getPosition_vec3w(s32 dst[3]);
+extern void viewport_getPosition_vec3s(s16 dst[3]);
+extern void viewport_getRotation_vec3f(f32 arg0[3]);
+extern f32 viewport_getYaw(void);
+extern void viewport_getRotation_f3(f32 *pitch, f32 *yaw, f32 *roll);
+extern void viewport_setRenderViewportAndOrthoMatrix(Gfx **gfx, Mtx **mtx);
+extern void viewport_setRenderViewportAndPerspectiveMatrix(Gfx **gfx, Mtx **mtx);
+extern void viewport_setRenderPerspectiveMatrix(Gfx **gfx, Mtx **mtx, f32 near, f32 far);
+extern void viewport_debug(void);
+extern void viewport_debug2(f32 arg0);
+extern f32 viewport_debug3(void);
+extern void viewport_pushFramebufferExtendsToVpStack(void);
+extern void viewport_reset(void);
+extern void viewport_debug4(int arg0);
+extern void viewport_setPosition_vec3f(f32 src[3]);
+extern void viewport_setPosition_vec3w(s32 src[3]);
+extern void viewport_setPosition_f3(f32 x, f32 y, f32 z);
+extern void viewport_setRotation_vec3f(f32 src[3]);
+extern void viewport_setRotation_f3(f32 pitch, f32 yaw, f32 roll);
+extern void viewport_setNearAndFar(f32 near, f32 far);
+extern void viewport_pushVpScaleAndTranslation(s32 scale_x, s32 scale_y, s32 translation_x, s32 translation_y);
+extern void viewport_unused_pushVpScaleAndTranslation(f32 scale_x, f32 scale_y, f32 translation_x, f32 translation_y);
+extern void viewport_update(void);
+extern void viewport_getFrustumPlanes(f32 arg0[4], f32 arg1[4], f32 arg2[4], f32 arg3[4]);
+extern void viewport_setFrustumPlanes(f32 arg0[4], f32 arg1[4], f32 arg2[4], f32 arg3[4]);
+extern bool viewport_isBoundingBoxInFrustum(f32 min[3], f32 max[3]);
+extern bool cube_isInFrustum(Cube *cube);
+extern bool cube_isInFrustum2(Cube *cube);
+extern bool viewport_func_8024DB50(f32 arg0[3], f32 arg1);
+extern bool viewport_isPointOutsideFrustum_3f(f32 x, f32 y, f32 z);
+extern bool viewport_isPointOutsideFrustum_vec3f(f32 arg0[3]);
+extern bool viewport_isPointPlane_3f(f32 arg0, f32 arg1, f32 arg2);
+extern Mtx *viewport_getMatrix(void);
+extern Mtx *viewport_getDefaultMatrix(void);
+extern f32 viewport_getFOVy(void);
+extern void viewport_setFOVy(f32 fovy);
+extern f32 viewport_getAspectRatio(void);
+extern f32 viewport_getNear(void);
+extern f32 viewport_func_8024DDD8(f32 arg0[3], f32 arg1);
+extern f32 viewport_func_8024DE1C(f32 arg0, f32 arg1, f32 arg2[3], f32 arg3[3]);
+extern bool viewport_func_8024E030(f32 arg0[3], f32 *arg1);
+extern void viewport_backupState(void);
+extern void viewport_restoreState(void);
+extern void viewport_adjustPointDistance(f32 pos[3], f32 distance);
+
 #endif
diff --git a/src/CC/code_1F70.c b/src/CC/code_1F70.c
index f9bacd11..f0292e54 100644
--- a/src/CC/code_1F70.c
+++ b/src/CC/code_1F70.c
@@ -18,7 +18,6 @@ extern int func_80340020(s32, f32[3], s32, f32, s32, BKVertexList *, f32[3], f32
 extern void boneTransformList_getBoneScale(s32, s32, f32[3]);
 extern void boneTransformList_setBoneScale(s32, s32, f32[3]);
 extern void func_8033A9A8(s32, s32, f32[3]);
-extern void viewport_getPosition_vec3f(f32[3]);
 extern void ml_vec3f_normalize(f32[3]);
 extern void func_8033A45C(s32, s32);
 extern void modelRender_setBoneTransformList(s32);
diff --git a/src/FP/ch/xmastreeeggtoll.c b/src/FP/ch/xmastreeeggtoll.c
index 1ce1a850..634261c9 100644
--- a/src/FP/ch/xmastreeeggtoll.c
+++ b/src/FP/ch/xmastreeeggtoll.c
@@ -2,8 +2,6 @@
 #include "functions.h"
 #include "variables.h"
 
-extern s32 func_8024DB50(f32[3], f32);
-
 void func_80390EB0(Actor *this);
 
 /* .data */
@@ -72,7 +70,7 @@ void func_80390EB0(Actor *this){
         marker_setCollisionScripts(this->marker, func_80390E78, NULL, NULL);
     }
 
-    if(func_8024DB50(this->position, 150.0f) || func_80329530(this, 1200))
+    if(viewport_func_8024DB50(this->position, 150.0f) || func_80329530(this, 1200))
     {
         if( !(globalTimer_getTime() & 3) && randf() < 0.2){
             func_80390C70(this->position);
diff --git a/src/GV/code_3BB0.c b/src/GV/code_3BB0.c
index 3f319c31..5dfcdcd2 100644
--- a/src/GV/code_3BB0.c
+++ b/src/GV/code_3BB0.c
@@ -2,8 +2,6 @@
 #include "functions.h"
 #include "variables.h"
 
-extern int func_8024DB50(f32[3], f32);
-
 void GV_func_8038A084(Actor *this);
 
 /* .data */
@@ -54,7 +52,7 @@ void GV_func_8038A084(Actor *this){
     }
 
     if(this->unkF4_8 == 6
-        && func_8024DB50(this->position, 50.0f)
+        && viewport_func_8024DB50(this->position, 50.0f)
         && !this->unk38_31
         && randf() < 0.2
     ){
diff --git a/src/core1/code_18350.c b/src/core1/code_18350.c
index e6598483..0c73aaa8 100644
--- a/src/core1/code_18350.c
+++ b/src/core1/code_18350.c
@@ -34,8 +34,6 @@ f32 ml_acosValTbl[90] = { //D_80276CBC
     0.0871559978, 0.0697569996, 0.0523359999, 0.0348990001, 0.0174519997
 };
 
-f32 viewport_getYaw(void);
-
 // .h
 void func_80257918(f32 arg0[3], f32 arg1[3], f32 arg2[3], f32 arg3[3]);
 void ml_vec3f_roll_rotate_copy(f32 arg0[3], f32 arg1[3], f32);
@@ -437,6 +435,7 @@ void func_80256D0C(f32 val1, f32 val2, f32 x, f32 y, f32 z, f32 *dstX, f32 *dstY
     *dstZ = tmp * cosf(val2) - sinf(val2) * x;
 }
 
+// rotates direction vector (x, y, z)
 void func_80256E24(f32 dst[3], f32 theta, f32 phi, f32 x, f32 y, f32 z)
 {
     f32 tmp;
diff --git a/src/core1/code_3A70.c b/src/core1/code_3A70.c
index bee10f29..0ce280b8 100644
--- a/src/core1/code_3A70.c
+++ b/src/core1/code_3A70.c
@@ -4,7 +4,6 @@
 
 extern f32 ml_cos_deg(f32);
 extern f32 ml_sin_deg(f32);
-extern void viewport_getPosition_vec3w(s32[3]);
 
 Gfx D_80275880[] = {
     gsSPClearGeometryMode(G_CULL_BOTH | G_FOG | G_LIGHTING | G_TEXTURE_GEN | G_TEXTURE_GEN_LINEAR | G_LOD | G_SHADING_SMOOTH | G_CLIPPING | 0x0060CD00),
diff --git a/src/core1/code_EAF0.c b/src/core1/code_EAF0.c
index 56385859..887b2498 100644
--- a/src/core1/code_EAF0.c
+++ b/src/core1/code_EAF0.c
@@ -2,9 +2,7 @@
 #include "functions.h"
 #include "variables.h"
 
-extern void guPerspective(Mtx *, u16*, f32, f32, f32, f32, f32);
 extern f32 ml_dotProduct_vec3f(f32[3], f32[3]);
-void func_80256E24(f32 [3], f32, f32, f32, f32, f32);
 
 #define VIEWPORT_FOVY_DEFAULT (40.0f)
 #define VIEWPORT_STACK_SIZE (8)
@@ -24,20 +22,14 @@ f32 sViewportMatrix[4][4];
 Mtx sViewportDefaultMatrix;
 s32 sViewportStackIndex;
 
-void viewport_setRenderPerspectiveMatrix(Gfx **, Mtx **, f32, f32);
-void viewport_debug4(int);
-void viewport_setPosition_f3(f32, f32, f32);
-void viewport_setRotation_f3(f32, f32, f32);
-void viewport_setNearAndFar(f32, f32);
-void viewport_pushVpScaleAndTranslation(s32 arg0, s32 arg1, s32 arg2, s32 arg3);
-void viewport_setFOVy(f32);
+void viewport_moveAlongZAxis(f32 offset) {
+    f32 delta_position[3];
 
-void func_8024C510(f32 arg0){
-    f32 sp24[3];
-    func_80256E24(sp24, sViewportRotation[0], sViewportRotation[1], 0.0f, 0.0f, arg0);
-    sViewportPosition[0] += sp24[0];
-    sViewportPosition[1] += sp24[1];
-    sViewportPosition[2] += sp24[2];
+    func_80256E24(delta_position, sViewportRotation[0], sViewportRotation[1], 0.0f, 0.0f, offset);
+
+    sViewportPosition[0] += delta_position[0];
+    sViewportPosition[1] += delta_position[1];
+    sViewportPosition[2] += delta_position[2];
 }
 
 f32 viewport_getDistance(f32 arg0[3]) {
@@ -53,15 +45,15 @@ void viewport_getPosition_vec3f(f32 arg0[3]) {
 }
 
 void viewport_getPosition_vec3w(s32 dst[3]) {
-    dst[0] = ((f32)(s32)(sViewportPosition[0]*500.0))/500.0;
-    dst[1] = ((f32)(s32)(sViewportPosition[1]*500.0))/500.0;
-    dst[2] = ((f32)(s32)(sViewportPosition[2]*500.0))/500.0;
+    dst[0] = ((f32)(s32)(sViewportPosition[0] * 500.0)) / 500.0;
+    dst[1] = ((f32)(s32)(sViewportPosition[1] * 500.0)) / 500.0;
+    dst[2] = ((f32)(s32)(sViewportPosition[2] * 500.0)) / 500.0;
 }
 
 void viewport_getPosition_vec3s(s16 dst[3]) {
-    dst[0] = ((f32)(s32)(sViewportPosition[0]*500.0))/500.0;
-    dst[1] = ((f32)(s32)(sViewportPosition[1]*500.0))/500.0;
-    dst[2] = ((f32)(s32)(sViewportPosition[2]*500.0))/500.0;
+    dst[0] = ((f32)(s32)(sViewportPosition[0] * 500.0)) / 500.0;
+    dst[1] = ((f32)(s32)(sViewportPosition[1] * 500.0)) / 500.0;
+    dst[2] = ((f32)(s32)(sViewportPosition[2] * 500.0)) / 500.0;
 }
 
 void viewport_getRotation_vec3f(f32 arg0[3]) {
@@ -94,18 +86,18 @@ void viewport_setRenderViewportAndPerspectiveMatrix(Gfx **gfx, Mtx **mtx) {
 }
 
 void viewport_setRenderPerspectiveMatrix(Gfx **gfx, Mtx **mtx, f32 near, f32 far) {
-    u16 sp5e;
+    u16 perspNorm;
 
     near = MAX(sViewportNear, near);
     far = MIN(sViewportFar, far);
 
-    if(*(u32*)OS_PHYSICAL_TO_K1(0x1D8) + 0x53D4FFF0){
+    if(*(u32*)OS_PHYSICAL_TO_K1(0x1D8) + 0x53D4FFF0) { // what's this?
         near = 750.0f; 
         far = 1250.0f;
     }
     
-    guPerspective(*mtx, &sp5e, sViewportFOVy, sViewportAspect, near, far, 0.5f);
-    gSPPerspNormalize((*gfx)++, sp5e);
+    guPerspective(*mtx, &perspNorm, sViewportFOVy, sViewportAspect, near, far, 0.5f);
+    gSPPerspNormalize((*gfx)++, perspNorm);
     gSPMatrix((*gfx)++, OS_PHYSICAL_TO_K0((*mtx)++), G_MTX_NOPUSH | G_MTX_LOAD | G_MTX_PROJECTION);
 
     guRotate(*mtx, -sViewportRotation[2], 0.0f, 0.0f, -1.0f);
@@ -128,8 +120,8 @@ void viewport_setRenderPerspectiveMatrixDefaultNearAndFar(Gfx **gfx, Mtx **mtx)
 void viewport_debug(void) {}
 
 void viewport_debug2(f32 arg0) {
-    if(90.0f < arg0) arg0 = 90.0f;
-    if(arg0 < 5.0f) arg0 = 10.0f;
+    if (90.0f < arg0) arg0 = 90.0f;
+    if (arg0 < 5.0f) arg0 = 10.0f;
     sViewportUnused1 = arg0;
 }
 
@@ -359,18 +351,20 @@ bool cube_isInFrustum2(Cube *cube) {
     return viewport_isBoundingBoxInFrustum(min, max);
 }
 
-bool func_8024DB50(f32 arg0[3], f32 arg1) {
+bool viewport_func_8024DB50(f32 arg0[3], f32 arg1) {
     f32 delta[3];
     s32 i;
 
     delta[0] = arg0[0] - sViewportPosition[0];
     delta[1] = arg0[1] - sViewportPosition[1];
     delta[2] = arg0[2] - sViewportPosition[2];
-    for(i = 0; i < 4; i++){
+
+    for(i = 0; i < 4; i++) {
         if(arg1 <= ml_dotProduct_vec3f(delta, sViewportFrustumPlanes[i])){
             return FALSE;
         }
     }
+
     return TRUE;
 }
 
@@ -389,7 +383,7 @@ bool viewport_isPointOutsideFrustum_vec3f(f32 arg0[3]) {
 }
 
 // need to figure out, what plane 2 is (neg/pos x/y ?)
-bool viewport_isPointPlane2_3f(f32 arg0, f32 arg1, f32 arg2) {
+bool viewport_isPointPlane_3f(f32 arg0, f32 arg1, f32 arg2) {
     return ((sViewportFrustumPlanes[2][0]*arg0 + sViewportFrustumPlanes[2][1]*arg1 + sViewportFrustumPlanes[2][2]*arg2 + sViewportFrustumPlanes[2][3]) <= 0.0f);
 }
 
@@ -417,11 +411,11 @@ f32 viewport_getNear(void) {
     return sViewportNear;
 }
 
-f32 func_8024DDD8(s32 arg0, f32 arg1) {
+f32 viewport_func_8024DDD8(f32 arg0[3], f32 arg1) {
     return mlNormalizeAngle((sViewportRotation[1] + arg1) + 90.0);
 }
 
-f32 func_8024DE1C(f32 arg0, f32 arg1, f32 arg2[3], f32 arg3[3]) {
+f32 viewport_func_8024DE1C(f32 arg0, f32 arg1, f32 arg2[3], f32 arg3[3]) {
     f32 fovy_rad;
     static f32 D_8028101C;
     static f32 D_80281020;
@@ -456,7 +450,7 @@ f32 sViewportBackupFrustumPlanes[4][4];
 f32 sViewportBackupLookVector[3];
 f32 sViewportBackupMatrix[4][4];
 
-bool func_8024E030(f32 arg0[3], f32 *arg1)
+bool viewport_func_8024E030(f32 arg0[3], f32 *arg1)
 {
     f32 sp34[3];
     f32 temp_f2_2;
@@ -473,20 +467,23 @@ bool func_8024E030(f32 arg0[3], f32 *arg1)
     ml_vec3f_pitch_rotate_copy(sp34, sp34, -sViewportRotation[0]);
 
     if ((-sViewportNear) <= sp34[2]) {
-        return 0;
+        return FALSE;
     }
 
     temp_f2 = gu_sqrtf((sp34[1] * sp34[1]) + (sp34[2] * sp34[2])) * sinf(fovy_radians);
     temp_f2_2 = (((f32) framebuffer_width) / ((f32) framebuffer_height)) * temp_f2;
+
     arg1[0] = (f32) (((sp34[0] / temp_f2_2) + 1) * (((f32) framebuffer_width) / 2));
     arg1[1] = (f32) ((1 - (sp34[1] / temp_f2)) * (((f32) framebuffer_height) / 2));
+
     if ((arg1[0] < (-((f32) framebuffer_width))) || ((((f32) framebuffer_width) * 2) < arg1[0])) {
-        return 0;
+        return FALSE;
     }
+
     if ((arg1[1] < (-((f32) framebuffer_height))) || ((((f32) framebuffer_height) * 2) < arg1[1])) {
-        return 0;
+        return FALSE;
     }
-    return 1;
+    return TRUE;
 }
 
 void viewport_backupState(void) {
diff --git a/src/core2/ba/marker.c b/src/core2/ba/marker.c
index eb6baa5d..7ccac94c 100644
--- a/src/core2/ba/marker.c
+++ b/src/core2/ba/marker.c
@@ -7,7 +7,6 @@
 #include "SnS.h"
 
 extern void func_803012F8(void);
-extern f32 func_8024DDD8(f32[3], f32);
 extern f32 ml_distanceSquared_vec3f(f32 arg0[3], f32 arg1[3]);
 extern void __baMarker_8028BA00(s32);
 extern void func_802C418C(void);
diff --git a/src/core2/ch/bottlesbonuscursor.c b/src/core2/ch/bottlesbonuscursor.c
index 98aac683..f6f809fd 100644
--- a/src/core2/ch/bottlesbonuscursor.c
+++ b/src/core2/ch/bottlesbonuscursor.c
@@ -86,7 +86,7 @@ void chBottlesBonusCursor_func_802DF460(s32 indx, ActorMarker *caller, f32 arg2[
     sp1C[0] = arg2[0] * 100.0f;
     sp1C[1] = arg2[1] * 100.0f;
     sp1C[2] = arg2[2] * 100.0f;
-    if (func_8024E030(sp1C, D_8037E068[indx]) == 0) {
+    if (viewport_func_8024E030(sp1C, D_8037E068[indx]) == 0) {
         D_8037E068[indx][0] = D_8037E068[indx][1] = 0.0f;
     }
 }
@@ -149,7 +149,7 @@ void chBottlesBonusCursor_draw(Gfx **gfx, Mtx **mtx, Vtx **vtx) {
     modelRender_postDraw((GenFunction_1)actor_postdrawMethod, (s32)chBottlesBonusCursorMarker);
     modelRender_setDepthMode(MODEL_RENDER_DEPTH_FULL);
     actor_setOpacity(this, 0xB9);
-    func_8024E030(this->position, D_8037E5C0.unk18);
+    viewport_func_8024E030(this->position, D_8037E5C0.unk18);
     sp3C = (this->scale * 650.0f);
     func_80253208(gfx, 
         (s32)(D_8037E5C0.unk18[0]  - sp3C/2), (s32)(D_8037E5C0.unk18[1] - sp3C/2),
@@ -157,7 +157,7 @@ void chBottlesBonusCursor_draw(Gfx **gfx, Mtx **mtx, Vtx **vtx) {
         D_803A5D00[getActiveFramebuffer()]
     );
     modelRender_draw(gfx, mtx, this->position, rotation, this->scale, NULL, marker_loadModelBin(chBottlesBonusCursorMarker));
-    func_8024E030(this->position, D_8037E5C0.unk10);
+    viewport_func_8024E030(this->position, D_8037E5C0.unk10);
     if (this->state == 1) {
         D_8037E5C0.unk10[0] -= 24.0f;
         D_8037E5C0.unk10[1] -= 8.0f;
diff --git a/src/core2/ch/firefx.c b/src/core2/ch/firefx.c
index fd3cfbcb..6f3397bc 100644
--- a/src/core2/ch/firefx.c
+++ b/src/core2/ch/firefx.c
@@ -2,8 +2,6 @@
 #include "functions.h"
 #include "variables.h"
 
-extern int  func_8024DB50(f32 arg0[3], f32 arg1);
-
 void chfirefx_update(Actor *this);
 
 /* .data */
@@ -75,7 +73,7 @@ void chfirefx_update(Actor *this){
         }
     }//L80359934
     if(subaddie_playerIsWithinSphere(this, 2000)){
-        if( func_8024DB50(this->position, 50.0f) && this->unk38_31 ){
+        if( viewport_func_8024DB50(this->position, 50.0f) && this->unk38_31 ){
             if(!(globalTimer_getTime() & 3) && randf() < 0.1){
                 __chfirefx_spawnSmoke(this->position, this->scale);
             } //L803599AC
diff --git a/src/core2/code_13FC0.c b/src/core2/code_13FC0.c
index 6855a490..50baa41f 100644
--- a/src/core2/code_13FC0.c
+++ b/src/core2/code_13FC0.c
@@ -2,7 +2,6 @@
 #include "functions.h"
 #include "variables.h"
 
-f32 func_8024DDD8(f32[3], f32);
 extern void func_8024E71C(s32, f32*);
 extern f32 ml_acosf(f32);
 extern f32 player_getYaw(void);
@@ -141,7 +140,7 @@ f32 func_8029B33C(void){
     f32 sp1C[3];
 
     _player_getPosition(sp1C);
-    return func_8024DDD8(sp1C, func_8029B2F4());
+    return viewport_func_8024DDD8(sp1C, func_8029B2F4());
 }
 
 s32 func_8029B370(void){
diff --git a/src/core2/code_14420.c b/src/core2/code_14420.c
index fb4e179c..de328f49 100644
--- a/src/core2/code_14420.c
+++ b/src/core2/code_14420.c
@@ -6,7 +6,6 @@
 #include "core2/ba/anim.h"
 #include "core2/ba/physics.h"
 
-f32 func_8024DDD8(f32[3], f32);
 extern void func_8024E71C(s32, f32*);
 extern f32 ml_acosf(f32);
 extern f32 player_getYaw(void);
diff --git a/src/core2/code_39D0.c b/src/core2/code_39D0.c
index 2c3ca98b..0e4b07ff 100644
--- a/src/core2/code_39D0.c
+++ b/src/core2/code_39D0.c
@@ -6,8 +6,6 @@
 #include "core2/statetimer.h"
 #include "core2/ba/physics.h"
 
-
-extern f32 func_8024DDD8(f32[3], f32);
 extern int func_80259254(f32 vec[3], f32 x, f32 z, f32 val);
 extern f32 player_getYaw(void);
 
@@ -144,8 +142,8 @@ bool func_8028AE10(void) {
 
     _player_getPosition(sp1C);
     ideal_yaw = yaw_getIdeal();
-    sp2C = func_8024DDD8(sp1C, 90.0f);
-    sp28 = func_8024DDD8(sp1C, 270.0f);
+    sp2C = viewport_func_8024DDD8(sp1C, 90.0f);
+    sp28 = viewport_func_8024DDD8(sp1C, 270.0f);
     if (sp28 < sp2C) {
         return (sp2C < ideal_yaw) || (ideal_yaw < sp28);
     }
diff --git a/src/core2/code_55180.c b/src/core2/code_55180.c
index eeaac631..aa3cafb8 100644
--- a/src/core2/code_55180.c
+++ b/src/core2/code_55180.c
@@ -3,9 +3,6 @@
 #include "variables.h"
 #include "core2/particle.h"
 
-
-extern bool func_8024DB50(f32[3], f32);
-
 void func_802DC208(Actor *this);
 
 /* .data */
@@ -57,7 +54,7 @@ void func_802DC208(Actor *this) {
         actor_collisionOff(this);
         this->marker->propPtr->unk8_3 = TRUE;
     }
-    if( func_8024DB50(this->position, 50.0f) 
+    if( viewport_func_8024DB50(this->position, 50.0f) 
         && func_802DC188() 
         && !(globalTimer_getTime() & 0x1F) 
         && randf() < 0.1
diff --git a/src/core2/code_5C870.c b/src/core2/code_5C870.c
index 1f742b65..2065c242 100644
--- a/src/core2/code_5C870.c
+++ b/src/core2/code_5C870.c
@@ -4,10 +4,6 @@
 
 #include "gc/gctransition.h"
 
-extern void func_8024C510(f32);
-extern void viewport_setPosition_f3(f32, f32, f32);
-extern void viewport_setRotation_f3(f32, f32, f32);
-extern void viewport_setNearAndFar(f32, f32);
 extern void func_802F5374(void);
 extern void func_802FA0F8(void);
 extern void timedFuncQueue_update(void);
@@ -66,7 +62,7 @@ struct{
 void func_802E3800(void){
     viewport_setPosition_f3(0.0f, 0.0f, 0.0f);
     viewport_setRotation_f3(-30.0f, 30.0f, 0.0f);
-    func_8024C510(3000.0f);
+    viewport_moveAlongZAxis(3000.0f);
     viewport_update();
 }
 
diff --git a/src/core2/code_70F20.c b/src/core2/code_70F20.c
index 3a5e952b..21572a3f 100644
--- a/src/core2/code_70F20.c
+++ b/src/core2/code_70F20.c
@@ -2,8 +2,6 @@
 #include "functions.h"
 #include "variables.h"
 
-extern s32 viewport_isPointPlane2_3f(f32,f32, f32);
-
 /* .code */
 void func_802F7EB0(struct3s *this){
     f32 plyrPos[3]; //sp74
@@ -37,7 +35,7 @@ void func_802F7EB0(struct3s *this){
     sp4C[1] = plyrPos[1] + sp4C[1];
     sp4C[2] = plyrPos[2] + sp4C[2];
     if(tmpf < 550.0)
-        for(i = 0; (i < 0xa) && viewport_isPointPlane2_3f(sp4C[0],sp4C[1]- 10.0f, sp4C[2]); i++){
+        for(i = 0; (i < 0xa) && viewport_isPointPlane_3f(sp4C[0],sp4C[1]- 10.0f, sp4C[2]); i++){
             sp4C[1] += 100.0f;
         }
 
diff --git a/src/core2/code_71820.c b/src/core2/code_71820.c
index 88097365..0e16d9d4 100644
--- a/src/core2/code_71820.c
+++ b/src/core2/code_71820.c
@@ -2,7 +2,6 @@
 #include "functions.h"
 #include "variables.h"
 
-extern int viewport_isPointPlane2_3f(f32, f32, f32);
 #define _SQ3(x, y, z)  (((x) * (x)) + ((y) * (y)) + ((z) * (z)))
 #define _SQ3v1(v)      (v[0] * v[0] + v[1] * v[1] + v[2] * v[2])
 
@@ -39,7 +38,7 @@ void func_802F87B0(struct6s *this){
     sp4C[1] += plyrPos[1];
     sp4C[2] += plyrPos[2];
     if(f20 < 600.0){
-        for(i = 0; i <10 && viewport_isPointPlane2_3f(sp4C[0], sp4C[1] - 10.0f, sp4C[2]); i++){
+        for(i = 0; i <10 && viewport_isPointPlane_3f(sp4C[0], sp4C[1] - 10.0f, sp4C[2]); i++){
             sp4C[1] += 100.0f;
         }
     }
diff --git a/src/core2/code_72060.c b/src/core2/code_72060.c
index 2465965b..ebf0fc8d 100644
--- a/src/core2/code_72060.c
+++ b/src/core2/code_72060.c
@@ -7,15 +7,12 @@ typedef struct {
     f32 unkC[3];
 }Struct_core2_72060_0;
 
-extern f32  viewport_getYaw();
-extern int  viewport_isPointPlane2_3f(f32, f32, f32);
 extern void func_80251B5C(f32, f32, f32);
 extern void mlMtx_rotate_pitch_deg(f32);
 extern void mlMtx_rotate_yaw_deg(f32);
 extern void func_80252A38(f32, f32, f32);
 extern void mlMtxApply(Mtx *);
 extern f32 vtxList_getGlobalNorm(BKVertexList *);
-extern bool func_8024DB50(f32[3], f32);
 
 struct4Cs *D_80369280 = NULL;
 
@@ -171,7 +168,7 @@ void func_802F919C(void) {
                 sp4C[1] += D_80381040[1];
                 sp4C[2] += D_80381040[2];
                 if (sp58 < 650.0) {
-                    for(sp44 = 0; sp44 < 5 && viewport_isPointPlane2_3f(sp4C[0], sp4C[1] - 10.0f, sp4C[2]) ; sp44++){
+                    for(sp44 = 0; sp44 < 5 && viewport_isPointPlane_3f(sp4C[0], sp4C[1] - 10.0f, sp4C[2]) ; sp44++){
                         sp4C[1] += 200.0f;
                     }
                 }
@@ -231,7 +228,7 @@ bool func_802F989C(Gfx **gfx, Mtx **mtx, f32 arg2[3]) {
     if( ((-17000.0f < D_80381070[0]) &&(D_80381070[0] < 17000.0f)) 
         && (arg2[1] > -200.0f)
         && ((-17000.0f < D_80381070[2]) && (D_80381070[2] < 17000.0f))
-        && func_8024DB50(arg2, D_8038108C)
+        && viewport_func_8024DB50(arg2, D_8038108C)
     ) {
         func_80251B5C(D_80381070[0], D_80381070[1], D_80381070[2]);
         mlMtxApply(*mtx);
diff --git a/src/core2/code_AD5B0.c b/src/core2/code_AD5B0.c
index e3949b2e..999fb59f 100644
--- a/src/core2/code_AD5B0.c
+++ b/src/core2/code_AD5B0.c
@@ -19,7 +19,6 @@ u32 D_803835E0;
 /* public */
 void func_80335110(s32);
 void func_80335128(s32);
-void viewport_setNearAndFar(f32, f32);
 void func_80335140(enum map_e);
 void func_8033520C(s32);
 
diff --git a/src/core2/code_AEDA0.c b/src/core2/code_AEDA0.c
index 6d04bc4b..a298cc57 100644
--- a/src/core2/code_AEDA0.c
+++ b/src/core2/code_AEDA0.c
@@ -2,7 +2,6 @@
 #include "functions.h"
 #include "variables.h"
 
-Mtx *viewport_getDefaultMatrix(void);
 void mlMtxSet(Mtx *);
 void func_80252330(f32, f32, f32);
 void mlMtxApply(Mtx *);
diff --git a/src/core2/code_BD100.c b/src/core2/code_BD100.c
index 4b8b177a..1f07fc4e 100644
--- a/src/core2/code_BD100.c
+++ b/src/core2/code_BD100.c
@@ -7,7 +7,6 @@ extern void func_80252330(f32, f32, f32);
 extern void mlMtxRotatePYR(f32, f32, f32);
 extern void mlMtxApply(Mtx *);
 extern void func_80349AD0(void);
-extern void viewport_getLookVector(f32[3]);
 
 
 
diff --git a/src/core2/code_C97F0.c b/src/core2/code_C97F0.c
index e3ece91a..f1c379f1 100644
--- a/src/core2/code_C97F0.c
+++ b/src/core2/code_C97F0.c
@@ -3,7 +3,6 @@
 #include "variables.h"
 
 extern bool func_8028F170(f32, f32);
-extern void viewport_getPosition_vec3f(f32[3]);
 
 typedef struct {
     f32 unk0;
diff --git a/src/core2/code_DB010.c b/src/core2/code_DB010.c
index 18d2ce2c..55456c4b 100644
--- a/src/core2/code_DB010.c
+++ b/src/core2/code_DB010.c
@@ -2,7 +2,6 @@
 #include "functions.h"
 #include "variables.h"
 
-extern int func_8024DB50(f32[3], f32 );
 extern void func_802EFF5C(ParticleEmitter *, f32, f32, f32);
 extern void func_802EFF7C(ParticleEmitter *, f32, f32, f32);
 extern void func_802EFF9C(ParticleEmitter *, f32);
@@ -487,17 +486,17 @@ void func_80362E94(Actor *this){
 
     switch(this->unkF4_8){
         case 0x3: //L80362ED8
-            if(func_8024DB50(this->position, 50.0f) && randf() < 0.2){
+            if(viewport_func_8024DB50(this->position, 50.0f) && randf() < 0.2){
                 func_80362084(this->position);
             }
             break;
         case 0xa: //L80362F24
-            if(func_8024DB50(this->position, 50.0f) && randf() < 0.1){
+            if(viewport_func_8024DB50(this->position, 50.0f) && randf() < 0.1){
                 func_8036247C(this->position);
             }
             break;
         case 0xc: //L80362F70
-            if(func_8024DB50(this->position, 50.0f)){
+            if(viewport_func_8024DB50(this->position, 50.0f)){
                 if(randf() < 0.4)
                     func_80362680(this->position);
                 if(randf() < 0.8)
@@ -505,27 +504,27 @@ void func_80362E94(Actor *this){
             }
             break;
         case 0x10://L80362FE8
-            if(func_8024DB50(this->position, 50.0f) && randf() < 0.1){
+            if(viewport_func_8024DB50(this->position, 50.0f) && randf() < 0.1){
                 func_80362A48(this->position);
             }
             break;
         case 0x11://L80363034
-            if(func_8024DB50(this->position, 50.0f) && randf() < 0.06){
+            if(viewport_func_8024DB50(this->position, 50.0f) && randf() < 0.06){
                 func_80362ADC(this->position);
             }
             break;
         case 0x12://L80363080
-            if(func_8024DB50(this->position, 50.0f) && randf() < 0.06){
+            if(viewport_func_8024DB50(this->position, 50.0f) && randf() < 0.06){
                 func_80362C04(this->position);
             }
             break;
         case 0x13://L803630CC
-            if(func_8024DB50(this->position, 50.0f) && randf() < 0.4){
+            if(viewport_func_8024DB50(this->position, 50.0f) && randf() < 0.4){
                 func_80362B70(this->position);
             }
             break;
         case 0x14://L80363118
-            if(func_8024DB50(this->position, 300.0f)){
+            if(viewport_func_8024DB50(this->position, 300.0f)){
                 if(randf() < 0.01)
                     func_80362C98(this->position);
                 func_80362D2C(this->position);
diff --git a/src/core2/fx/common3score.c b/src/core2/fx/common3score.c
index 09918d5f..f4dfa4bb 100644
--- a/src/core2/fx/common3score.c
+++ b/src/core2/fx/common3score.c
@@ -2,7 +2,6 @@
 #include "functions.h"
 #include "variables.h"
 
-extern f32 func_8024DE1C(f32, f32, f32[3], f32[3]);
 extern f32 vtxList_getGlobalNorm(BKVertexList *);
 extern void func_80253208(Gfx **gdl, s32 x, s32 y, s32 w, s32 h, void *color_buffer);
 
@@ -192,7 +191,7 @@ void fxcommon3score_draw(enum item_e item_id, void *arg1, Gfx **gfx, Mtx **mtx,
         a1->value_string[0] = '\0';
         strIToA(a1->value_string, itemPrint_getValue(item_id));
         print_bold_spaced(a1->unk30 + a1->unk40, sp40 + a1->unk44, a1->value_string);
-        sp3C = func_8024DE1C(a1->unk30, sp40, sp5C, sp68);
+        sp3C = viewport_func_8024DE1C(a1->unk30, sp40, sp5C, sp68);
 
         sp44[0] = 0.0f;
         sp44[1] = a1->unk38;
diff --git a/src/core2/gc/pauseMenu.c b/src/core2/gc/pauseMenu.c
index 83875979..5f736465 100644
--- a/src/core2/gc/pauseMenu.c
+++ b/src/core2/gc/pauseMenu.c
@@ -25,7 +25,6 @@ typedef struct struct_1A_s{
 extern void func_802C5994(void);
 extern void func_802E412C(s32, s32);
 void volatileFlag_set(s32, s32);
-f32 func_8024DE1C(f32, f32, f32 *, f32 *);
 void mlMtxApply(Mtx*);
 void func_80310D2C(void);
 
@@ -1210,7 +1209,7 @@ void __gcpausemenu_drawSprite(Gfx** gdl, Mtx** mptr, Vtx** vptr, BKSprite* sprit
     func_8033837C(0);
     viewport_getPosition_vec3f(sp50);
     
-    sp34 = func_8024DE1C(x, y, sp5C, sp44);
+    sp34 = viewport_func_8024DE1C(x, y, sp5C, sp44);
     mlMtxIdent(); //matrix_stack_identity
     sp38[0] = sp5C[0] - sp50[0];
     sp38[1] = sp5C[1] - sp50[1];
diff --git a/src/core2/gc/sky.c b/src/core2/gc/sky.c
index 03877d5f..299a92a3 100644
--- a/src/core2/gc/sky.c
+++ b/src/core2/gc/sky.c
@@ -2,8 +2,6 @@
 #include "functions.h"
 #include "variables.h"
 
-extern void viewport_setNearAndFar(f32, f32);
-
 typedef struct {
     s16 model_id;
     // u8 pad2[0x2];
diff --git a/src/core2/gc/transition.c b/src/core2/gc/transition.c
index 5efdc98e..28c06074 100644
--- a/src/core2/gc/transition.c
+++ b/src/core2/gc/transition.c
@@ -7,7 +7,6 @@
 void animctrl_setAnimTimer(AnimCtrl*, f32);
 void func_8025AC20(s32, s32, s32, f32, char*, s32);
 f32 func_80257618(void);
-void viewport_setNearAndFar(f32, f32);
 
 typedef enum {
     TRANSITION_ID_1_BLACK_IN = 1,
diff --git a/src/core2/gc/zoombox.c b/src/core2/gc/zoombox.c
index 7ed1314c..825eee6a 100644
--- a/src/core2/gc/zoombox.c
+++ b/src/core2/gc/zoombox.c
@@ -3,7 +3,6 @@
 #include "variables.h"
 #include "zoombox.h"
 
-extern f32 func_8024DE1C(f32, f32, f32[3], f32[3]);
 void func_80252330(f32, f32, f32);
 extern f32 func_8033DDB8(void);
 extern void func_8024E60C(s32, void *);
@@ -823,7 +822,7 @@ void func_803163A8(GcZoombox *this, Gfx **gfx, Mtx **mtx) {
     f32 sp38[3];
     f32 sp34;
 
-    sp34 = func_8024DE1C(this->unk170, this->unk172, sp50, sp5C);
+    sp34 = viewport_func_8024DE1C(this->unk170, this->unk172, sp50, sp5C);
     if (this->unk1A4_24) {
         sp5C[1] += 180.0f;
         sp5C[0] -= 2*sp5C[0];
diff --git a/src/core2/modelRender.c b/src/core2/modelRender.c
index 71ba1eed..a793c627 100644
--- a/src/core2/modelRender.c
+++ b/src/core2/modelRender.c
@@ -10,13 +10,7 @@ extern bool func_802ED420(BKModelUnk20List *arg0, u8 *arg1, u32 arg2);
 extern void func_802ED52C(BKModelUnk20List *, f32[3], f32);
 extern void func_80252AF0(f32[3], f32[3], f32[3], f32, f32[3]);
 extern void mlMtxRotatePYR(f32, f32, f32);
-extern void viewport_getPosition_vec3f(f32[3]);
-extern void viewport_getRotation_vec3f(f32[3]);
-extern void viewport_setPosition_vec3f(f32[3]);
-extern void viewport_setRotation_vec3f(f32[3]);
-extern void viewport_update(void);
 extern void func_8033BD4C(BKModelBin *);
-extern s32 func_8024DB50(f32[3], f32);
 extern void mlMtx_push_translation(f32, f32, f32);
 extern void mlMtxScale(f32);
 extern void mlMtxApply(Mtx* mtx);
@@ -959,7 +953,7 @@ void func_80338EB8(Gfx ** gfx, Mtx ** mtx, void *arg2){
         sp34[1] = (f32)cmd->unk8[1] * modelRenderScale;
         sp34[2] = (f32)cmd->unk8[2] * modelRenderScale;
         sp30 = (f32)cmd->unkE*modelRenderScale;
-        if(func_8024DB50(sp34, sp30) && cmd->unk10){
+        if(viewport_func_8024DB50(sp34, sp30) && cmd->unk10){
             func_80339124(gfx, mtx, (BKGeoList*)((s32)cmd + cmd->unk10));
         }
     }
@@ -981,7 +975,7 @@ void func_80338EB8(Gfx ** gfx, Mtx ** mtx, void *arg2){
         sp34[0] += modelRenderCameraPosition[0];
         sp34[1] += modelRenderCameraPosition[1];
         sp34[2] += modelRenderCameraPosition[2];
-        if(func_8024DB50(sp34, sp30) && cmd->unk10){
+        if(viewport_func_8024DB50(sp34, sp30) && cmd->unk10){
             func_80339124(gfx, mtx, (BKGeoList*)((s32)cmd + cmd->unk10));
         }
 
@@ -1102,7 +1096,7 @@ BKModelBin *modelRender_draw(Gfx **gfx, Mtx **mtx, f32 position[3], f32 rotation
         return 0;
     }
 
-    D_80370990 = (D_80383704) ? func_8024DB50(object_position, spD0*scale) : 1;
+    D_80370990 = (D_80383704) ? viewport_func_8024DB50(object_position, spD0*scale) : 1;
     if(D_80370990 == 0){
         modelRender_reset();
         return 0;
diff --git a/src/core2/nc/dynamicCamera.c b/src/core2/nc/dynamicCamera.c
index cf1446c5..d3397b45 100644
--- a/src/core2/nc/dynamicCamera.c
+++ b/src/core2/nc/dynamicCamera.c
@@ -5,7 +5,6 @@
 extern bool func_80245314(f32[3], f32[3], f32, f32, u32);
 extern int func_80244D94(f32[3], f32[3], f32[3], u32, f32);
 extern int func_8024575C(f32[3], f32[3], f32, f32[3], s32, u32);
-extern void func_8024C510(f32);
 extern f32 func_80258708(f32[3], f32[3]);
 extern f32 func_80259198(f32, f32);
 extern f32 func_8028E82C(void);
@@ -962,7 +961,7 @@ void func_802BE794(void){
         sp20[1] = mlNormalizeAngle(sp20[1] + 180.0f);
         viewport_setPosition_vec3f(sp2C);
         viewport_setRotation_vec3f(sp20);
-        func_8024C510(300.0f);
+        viewport_moveAlongZAxis(300.0f);
         func_802BE720();
     }//L802BE828
 }
diff --git a/src/core2/particle.c b/src/core2/particle.c
index 4562cfe3..fd78aaa6 100644
--- a/src/core2/particle.c
+++ b/src/core2/particle.c
@@ -3,7 +3,6 @@
 #include "variables.h"
 #include "core2/particle.h"
 
-extern int func_8024DB50(f32 (*)[3], f32);
 extern s32 spriteGetFrameCount(BKSprite *);
 extern void func_80344720(s32 SpriteGfx, s32 frame, s32, f32[3], f32[3], f32[3], Gfx **, Mtx **);
 extern void func_80344424(s32 SpriteGfx, s32 frame, s32, f32[3], f32[3], f32, Gfx **, Mtx **);
@@ -645,7 +644,7 @@ void particleEmitter_update(ParticleEmitter *this){
                 }//L802F0254
 
                 if( 0.0f != this->unkFC 
-                    && !func_8024DB50(&particle->position, this->unkFC)
+                    && !viewport_func_8024DB50(&particle->position, this->unkFC)
                 ){
                     memcpy(particle, --this->pList_end_128, sizeof(Particle));
                 }
diff --git a/src/fight/chbossjinjo.c b/src/fight/chbossjinjo.c
index 49d00a68..b8f0a32a 100644
--- a/src/fight/chbossjinjo.c
+++ b/src/fight/chbossjinjo.c
@@ -4,8 +4,6 @@
 #include "fight.h"
 #include "core2/particle.h"
 
-
-extern void viewport_getPosition_vec3f(f32 (*)[3]);
 extern void subaddie_set_state_with_direction(Actor *, s32, f32, s32);
 extern void func_80386654(f32 arg0, f32 (*arg1)[4], f32 (*arg2)[4]);
 extern void func_80324CFC(f32, enum comusic_e, s32);