Interpolation: Camera interpolation skip for cutscenes

2 files changed, 142 insertions, 0 deletions

diff --git a/src/engine/camera_interp_skip.c b/src/engine/camera_interp_skip.c
new file mode 100644
index 00000000..2a458a5a
--- /dev/null
+++ b/src/engine/camera_interp_skip.c
@@ -0,0 +1,108 @@
+#include "global.h"
+
+#define SQXYZ(vec) ((vec.x) * (vec.x) + (vec.y) * (vec.y) + (vec.z) * (vec.z))
+
+void Math_Vec3f_Diff(Vec3f* l, Vec3f* r, Vec3f* dest) {
+    dest->x = l->x - r->x;
+    dest->y = l->y - r->y;
+    dest->z = l->z - r->z;
+}
+
+void Math_Vec3f_Sum(Vec3f* l, Vec3f* r, Vec3f* dest) {
+    dest->x = l->x + r->x;
+    dest->y = l->y + r->y;
+    dest->z = l->z + r->z;
+}
+
+f32 Math_Vec3f_DistXYZ(Vec3f* a, Vec3f* b) {
+    Vec3f diff;
+    Math_Vec3f_Diff(b, a, &diff);
+    return sqrtf(SQXYZ(diff));
+}
+
+bool should_interpolate_perspective(Vec3f* eye, Vec3f* at) {
+    static Vec3f prev_eye = { 0, 0, 0 };
+    static Vec3f prev_at = { 0, 0, 0 };
+    static Vec3f eye_velocity = { 0, 0, 0 };
+    static Vec3f at_velocity = { 0, 0, 0 };
+
+    Vec3f predicted_eye;
+    Vec3f predicted_at;
+    // Predict the new eye and at positions based on the previous velocity and positions.
+    Math_Vec3f_Sum(&prev_eye, &eye_velocity, &predicted_eye);
+    Math_Vec3f_Sum(&prev_at, &at_velocity, &predicted_at);
+
+    // Calculate the current velocities from the previous and current positions.
+    Math_Vec3f_Diff(eye, &prev_eye, &eye_velocity);
+    Math_Vec3f_Diff(at, &prev_at, &at_velocity);
+
+    // Compare the predicted positions to the real positions.
+    float eye_dist = Math_Vec3f_DistXYZ(&predicted_eye, eye);
+    float at_dist = Math_Vec3f_DistXYZ(&predicted_at, at);
+
+    // Compare the velocities of the eye and at positions.
+    float velocity_diff = Math_Vec3f_DistXYZ(&eye_velocity, &at_velocity);
+
+    // Update the tracking for the previous positions with the new ones.
+    prev_eye = *eye;
+    prev_at = *at;
+
+    // These numbers are all picked via testing.
+
+    // If the velocity of both positions was the same, then they're moving together and should interpolate.
+    if (velocity_diff <= 3.0f && eye_dist <= 100.0f && at_dist <= 100.0f) {
+        return true;
+    }
+
+    // If the focus or position are basically the same across frames and the eye didn't move too far then it should
+    // probably be interpolated.
+    if (at_dist <= 20.0f && eye_dist <= 300.0f) {
+        return true;
+    }
+    if (eye_dist <= 20.0f && at_dist <= 300.0f) {
+        return true;
+    }
+
+    // Force camera interpolation during the all-range transition
+    if (gPlayer[0].state == PLAYERSTATE_START_360) {
+        return true;
+    }
+
+    // Force camera interpolation during camera shake
+    if (gCameraShake > 0 || gCameraShake > 0) {
+        return true;
+    }
+
+    switch (gCurrentLevel) {
+        // For Robot destroy cutscenes
+        case LEVEL_SECTOR_Y:
+            if (velocity_diff > 100.0f || at_dist > 500.0f || eye_dist > 500.0f) {
+                eye_velocity.x = 0.0f;
+                eye_velocity.y = 0.0f;
+                eye_velocity.z = 0.0f;
+                at_velocity.x = 0.0f;
+                at_velocity.y = 0.0f;
+                at_velocity.z = 0.0f;
+
+                printf("velocity_diff: %f\n at_dist: %f\n eye_dist: %f\n", velocity_diff, at_dist, eye_dist);
+                return false;
+            }
+            break;
+
+        default:
+            if (velocity_diff > 200.0f || at_dist > 150.0f || eye_dist > 300.0f) {
+                eye_velocity.x = 0.0f;
+                eye_velocity.y = 0.0f;
+                eye_velocity.z = 0.0f;
+                at_velocity.x = 0.0f;
+                at_velocity.y = 0.0f;
+                at_velocity.z = 0.0f;
+
+                printf("velocity_diff: %f\n at_dist: %f\n eye_dist: %f\n", velocity_diff, at_dist, eye_dist);
+                return false;
+            }
+            break;
+    }
+
+    return true;
+}
\ No newline at end of file
diff --git a/src/engine/fox_display.c b/src/engine/fox_display.c
index bcf769a9..fae15d6f 100644
--- a/src/engine/fox_display.c
+++ b/src/engine/fox_display.c
@@ -1,5 +1,6 @@
 #include "global.h"
 #include "mods/hit64.c"
+#include "camera_interp_skip.c"
 #include "assets/ast_arwing.h"
 #include "assets/ast_allies.h"
 #include "assets/ast_landmaster.h"
@@ -1877,6 +1878,31 @@ void Display_Update(void) {
         gPlayCamAt.y = camPlayer->cam.at.y;
         gPlayCamAt.z = camPlayer->cam.at.z;
     }
+
+    static PlayState prevPlayState = 0;
+    static int camSkipTimes = 0;
+
+    bool bigJump = !should_interpolate_perspective(&gPlayCamEye, &gPlayCamAt);
+
+    // @port: Force interpolation camera skip if we're transitioning to or from a pause state.
+    if (((prevPlayState == PLAY_PAUSE) && (gPlayState == PLAY_UPDATE)) ||
+        ((prevPlayState == PLAY_UPDATE) && (gPlayState == PLAY_PAUSE))) {
+        bigJump = true;
+    }
+
+    if (bigJump) {
+        // @port Skip interpolation
+        FrameInterpolation_ShouldInterpolateFrame(false);
+        printf("CAMERA 1 SKIPED: %d\n", camSkipTimes++);
+        gCamera1Skipped = true;
+    } else {
+        FrameInterpolation_RecordOpenChild("GamePlayCam", 0);
+        FrameInterpolation_RecordMarker(__FILE__, __LINE__);
+        gCamera1Skipped = false;
+    }
+
+    prevPlayState = gPlayState;
+
     camPlayer->camYaw = -Math_Atan2F(gPlayCamEye.x - gPlayCamAt.x, gPlayCamEye.z - gPlayCamAt.z);
     camPlayer->camPitch = -Math_Atan2F(gPlayCamEye.y - gPlayCamAt.y,
                                        sqrtf(SQ(gPlayCamEye.z - gPlayCamAt.z) + SQ(gPlayCamEye.x - gPlayCamAt.x)));
@@ -2051,6 +2077,14 @@ void Display_Update(void) {
         HUD_Draw();
         HUD_EdgeArrows_Update();
     }
+
+    if (bigJump) {
+        // @port Re-enable Interpolation if it was skipped
+        FrameInterpolation_ShouldInterpolateFrame(true);
+    } else {
+        FrameInterpolation_RecordCloseChild();
+    }
+
     Matrix_Pop(&gGfxMatrix);
     Display_DrawHelpAlert();
     sPlayersVisible[gPlayerNum] = false;