diff --git a/include/functions.h b/include/functions.h
index 273f13af..f3e2903b 100644
--- a/include/functions.h
+++ b/include/functions.h
@@ -612,7 +612,7 @@ extern void viewport_setFrustumPlanes(f32 arg0[4], f32 arg1[4], f32 arg2[4], f32
 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_func_8024DB50(f32 pos[3], f32 distance);
 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);
@@ -622,9 +622,9 @@ 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 f32 viewport_adjustAngleToRight(f32 pos[3], f32 angle);
+extern f32 viewport_transformCoordinate(f32 x, f32 y, f32 viewport_translation[3], f32 viewport_rotation[3]);
+extern bool viewport_func_8024E030(f32 pos[3], f32 *arg1);
 extern void viewport_backupState(void);
 extern void viewport_restoreState(void);
 extern void viewport_adjustPointDistance(f32 pos[3], f32 distance);
diff --git a/src/core1/code_18350.c b/src/core1/code_18350.c
index 0c73aaa8..3695831a 100644
--- a/src/core1/code_18350.c
+++ b/src/core1/code_18350.c
@@ -1044,6 +1044,7 @@ f32 ml_cos_deg(f32 angle_deg)
     return cosf(angle_deg * BAD_DTOR);
 }
 
+// brings angle in range between 0 and 360 degrees
 f32 mlNormalizeAngle(f32 angle)
 {
     if (angle < 0.0) // f64
diff --git a/src/core1/code_EAF0.c b/src/core1/code_EAF0.c
index 887b2498..2f0d5d7f 100644
--- a/src/core1/code_EAF0.c
+++ b/src/core1/code_EAF0.c
@@ -351,16 +351,17 @@ bool cube_isInFrustum2(Cube *cube) {
     return viewport_isBoundingBoxInFrustum(min, max);
 }
 
-bool viewport_func_8024DB50(f32 arg0[3], f32 arg1) {
+// viewport_distanceFromPlane ?
+bool viewport_func_8024DB50(f32 pos[3], f32 distance) {
     f32 delta[3];
     s32 i;
 
-    delta[0] = arg0[0] - sViewportPosition[0];
-    delta[1] = arg0[1] - sViewportPosition[1];
-    delta[2] = arg0[2] - sViewportPosition[2];
+    delta[0] = pos[0] - sViewportPosition[0];
+    delta[1] = pos[1] - sViewportPosition[1];
+    delta[2] = pos[2] - sViewportPosition[2];
 
     for(i = 0; i < 4; i++) {
-        if(arg1 <= ml_dotProduct_vec3f(delta, sViewportFrustumPlanes[i])){
+        if(distance <= ml_dotProduct_vec3f(delta, sViewportFrustumPlanes[i])) {
             return FALSE;
         }
     }
@@ -411,37 +412,42 @@ f32 viewport_getNear(void) {
     return sViewportNear;
 }
 
-f32 viewport_func_8024DDD8(f32 arg0[3], f32 arg1) {
-    return mlNormalizeAngle((sViewportRotation[1] + arg1) + 90.0);
+f32 viewport_adjustAngleToRight(f32 pos[3], f32 angle) {
+    return mlNormalizeAngle((sViewportRotation[1] + angle) + 90.0);
 }
 
-f32 viewport_func_8024DE1C(f32 arg0, f32 arg1, f32 arg2[3], f32 arg3[3]) {
+f32 viewport_transformCoordinate(f32 x, f32 y, f32 viewport_translation[3], f32 viewport_rotation[3]) {
     f32 fovy_rad;
-    static f32 D_8028101C;
-    static f32 D_80281020;
-    static f32 D_80281024;
+    static f32 fovy;
+    static f32 near;
+    static f32 scale;
 
-    if ((sViewportFOVy != D_8028101C) || (sViewportNear != D_80281020)) {
+    if ((sViewportFOVy != fovy) || (sViewportNear != near)) {
         fovy_rad = (sViewportFOVy * M_PI) / 360.0;
-        D_80281024 = (500.0 + sViewportNear) / (((framebuffer_height / (f32)2) / sinf(fovy_rad)) * cosf(fovy_rad));
-        D_8028101C = sViewportFOVy;
-        D_80281020 = sViewportNear;
+        scale = (500.0 + sViewportNear) / (((framebuffer_height / (f32)2) / sinf(fovy_rad)) * cosf(fovy_rad));
+        fovy = sViewportFOVy;
+        near = sViewportNear;
     }
-    arg0 = arg0 - (framebuffer_width / (f32)2);
-    arg1 = (framebuffer_height / (f32)2) - arg1;
-    arg3[0] = sViewportRotation[0];
-    arg3[1] = sViewportRotation[1];
-    arg3[2] = sViewportRotation[2];
-    arg2[0] = arg0 * D_80281024;
-    arg2[1] = arg1 * D_80281024;
-    arg2[2] = (-500.0 - sViewportNear);
-    ml_vec3f_pitch_rotate_copy(arg2, arg2, arg3[0]);
-    ml_vec3f_yaw_rotate_copy(arg2, arg2, arg3[1]);
+
+    x = x - (framebuffer_width / (f32)2);
+    y = (framebuffer_height / (f32)2) - y;
+
+    viewport_rotation[0] = sViewportRotation[0];
+    viewport_rotation[1] = sViewportRotation[1];
+    viewport_rotation[2] = sViewportRotation[2];
+
+    viewport_translation[0] = x * scale;
+    viewport_translation[1] = y * scale;
+    viewport_translation[2] = (-500.0 - sViewportNear);
+
+    ml_vec3f_pitch_rotate_copy(viewport_translation, viewport_translation, viewport_rotation[0]);
+    ml_vec3f_yaw_rotate_copy(viewport_translation, viewport_translation, viewport_rotation[1]);
     
-    arg2[0] += sViewportPosition[0];
-    arg2[1] += sViewportPosition[1];
-    arg2[2] += sViewportPosition[2];
-    return D_80281024;
+    viewport_translation[0] += sViewportPosition[0];
+    viewport_translation[1] += sViewportPosition[1];
+    viewport_translation[2] += sViewportPosition[2];
+
+    return scale;
 }
 
 f32 sViewportBackupPosition[3];
@@ -450,31 +456,32 @@ f32 sViewportBackupFrustumPlanes[4][4];
 f32 sViewportBackupLookVector[3];
 f32 sViewportBackupMatrix[4][4];
 
-bool viewport_func_8024E030(f32 arg0[3], f32 *arg1)
+// ??
+bool viewport_func_8024E030(f32 pos[3], f32 *arg1)
 {
-    f32 sp34[3];
+    f32 delta[3];
     f32 temp_f2_2;
     f32 temp_f2;
     f32 fovy_radians;
 
     fovy_radians = (sViewportFOVy * M_PI) / 360.0;
 
-    sp34[0] = arg0[0] - sViewportPosition[0];
-    sp34[1] = arg0[1] - sViewportPosition[1];
-    sp34[2] = arg0[2] - sViewportPosition[2];
+    delta[0] = pos[0] - sViewportPosition[0];
+    delta[1] = pos[1] - sViewportPosition[1];
+    delta[2] = pos[2] - sViewportPosition[2];
 
-    ml_vec3f_yaw_rotate_copy(sp34, sp34, -sViewportRotation[1]);
-    ml_vec3f_pitch_rotate_copy(sp34, sp34, -sViewportRotation[0]);
+    ml_vec3f_yaw_rotate_copy(delta, delta, -sViewportRotation[1]);
+    ml_vec3f_pitch_rotate_copy(delta, delta, -sViewportRotation[0]);
 
-    if ((-sViewportNear) <= sp34[2]) {
+    if ((-sViewportNear) <= delta[2]) {
         return FALSE;
     }
 
-    temp_f2 = gu_sqrtf((sp34[1] * sp34[1]) + (sp34[2] * sp34[2])) * sinf(fovy_radians);
+    temp_f2 = gu_sqrtf((delta[1] * delta[1]) + (delta[2] * delta[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));
+    arg1[0] = (f32) (((delta[0] / temp_f2_2) + 1) * (((f32) framebuffer_width) / 2));
+    arg1[1] = (f32) ((1 - (delta[1] / temp_f2)) * (((f32) framebuffer_height) / 2));
 
     if ((arg1[0] < (-((f32) framebuffer_width))) || ((((f32) framebuffer_width) * 2) < arg1[0])) {
         return FALSE;
@@ -483,6 +490,7 @@ bool viewport_func_8024E030(f32 arg0[3], f32 *arg1)
     if ((arg1[1] < (-((f32) framebuffer_height))) || ((((f32) framebuffer_height) * 2) < arg1[1])) {
         return FALSE;
     }
+
     return TRUE;
 }
 
diff --git a/src/core2/code_13FC0.c b/src/core2/code_13FC0.c
index 50baa41f..8087dcd5 100644
--- a/src/core2/code_13FC0.c
+++ b/src/core2/code_13FC0.c
@@ -140,7 +140,7 @@ f32 func_8029B33C(void){
     f32 sp1C[3];
 
     _player_getPosition(sp1C);
-    return viewport_func_8024DDD8(sp1C, func_8029B2F4());
+    return viewport_adjustAngleToRight(sp1C, func_8029B2F4());
 }
 
 s32 func_8029B370(void){
diff --git a/src/core2/code_39D0.c b/src/core2/code_39D0.c
index 0e4b07ff..8419e9ec 100644
--- a/src/core2/code_39D0.c
+++ b/src/core2/code_39D0.c
@@ -142,8 +142,8 @@ bool func_8028AE10(void) {
 
     _player_getPosition(sp1C);
     ideal_yaw = yaw_getIdeal();
-    sp2C = viewport_func_8024DDD8(sp1C, 90.0f);
-    sp28 = viewport_func_8024DDD8(sp1C, 270.0f);
+    sp2C = viewport_adjustAngleToRight(sp1C, 90.0f);
+    sp28 = viewport_adjustAngleToRight(sp1C, 270.0f);
     if (sp28 < sp2C) {
         return (sp2C < ideal_yaw) || (ideal_yaw < sp28);
     }
diff --git a/src/core2/fx/common3score.c b/src/core2/fx/common3score.c
index f4dfa4bb..c4333ef7 100644
--- a/src/core2/fx/common3score.c
+++ b/src/core2/fx/common3score.c
@@ -191,7 +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 = viewport_func_8024DE1C(a1->unk30, sp40, sp5C, sp68);
+        sp3C = viewport_transformCoordinate(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 5f736465..f706830b 100644
--- a/src/core2/gc/pauseMenu.c
+++ b/src/core2/gc/pauseMenu.c
@@ -1209,7 +1209,7 @@ void __gcpausemenu_drawSprite(Gfx** gdl, Mtx** mptr, Vtx** vptr, BKSprite* sprit
     func_8033837C(0);
     viewport_getPosition_vec3f(sp50);
     
-    sp34 = viewport_func_8024DE1C(x, y, sp5C, sp44);
+    sp34 = viewport_transformCoordinate(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/zoombox.c b/src/core2/gc/zoombox.c
index 825eee6a..687151e1 100644
--- a/src/core2/gc/zoombox.c
+++ b/src/core2/gc/zoombox.c
@@ -822,7 +822,7 @@ void func_803163A8(GcZoombox *this, Gfx **gfx, Mtx **mtx) {
     f32 sp38[3];
     f32 sp34;
 
-    sp34 = viewport_func_8024DE1C(this->unk170, this->unk172, sp50, sp5C);
+    sp34 = viewport_transformCoordinate(this->unk170, this->unk172, sp50, sp5C);
     if (this->unk1A4_24) {
         sp5C[1] += 180.0f;
         sp5C[0] -= 2*sp5C[0];