From 47c64e3bf342094db0b5648717a15e2e13589626 Mon Sep 17 00:00:00 2001
From: Epicalert <epicalert@protonmail.com>
Date: Tue, 13 Apr 2021 15:52:46 +0800
Subject: [PATCH] Add smoothing

Transform of each part is now smoothed over 4 frames to stop shaking.
---
 TODO.md           |  5 ++++-
 src/model.cpp     |  1 -
 src/modelpart.cpp | 27 ++++++++++++++++++++++++++-
 src/modelpart.hpp |  9 +++++++++
 4 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/TODO.md b/TODO.md
index 7565add..41ccc35 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,7 +1,6 @@
 # Before 1.0
 
 ## graphics
-- smoothing
 
 ## docs
 - getting started guide
@@ -9,3 +8,7 @@
 
 ## models
 - better default model
+
+## vision
+- eye open/closed
+- eye look direction
diff --git a/src/model.cpp b/src/model.cpp
index 11b0261..4b0e876 100644
--- a/src/model.cpp
+++ b/src/model.cpp
@@ -140,7 +140,6 @@ Model::Model(const char* path) {
 		}
 
 		// offsets
-
 		auto posOffsetArray = partsVec[i].getArray("pos_offset");
 		if (posOffsetArray) {
 			auto offsetVec = *posOffsetArray->getDoubleVector();
diff --git a/src/modelpart.cpp b/src/modelpart.cpp
index d4343fe..d5001b6 100644
--- a/src/modelpart.cpp
+++ b/src/modelpart.cpp
@@ -40,6 +40,31 @@ void ModelPart::setFollowTarget(std::string followTarget) {
        follow = bindStringToNum[followTarget];
 }
 
+void ModelPart::smoothTransform(glm::vec2 position, float rotation, float scale) {
+	histPositions[histI] = position;
+	histRotations[histI] = rotation;
+	histScales[histI] = scale;
+
+	histI++;
+	histI = histI % SMOOTHING_FRAMES;
+
+	glm::vec2 smoothedPosition(0,0);
+	float smoothedRotation = 0;
+	float smoothedScale = 0;
+
+	for(size_t i = 0; i < SMOOTHING_FRAMES; i++) {
+		smoothedPosition += histPositions[i];
+		smoothedRotation += histRotations[i];
+		smoothedScale += histScales[i];
+	}
+
+	smoothedPosition /= SMOOTHING_FRAMES;
+	smoothedRotation /= SMOOTHING_FRAMES;
+	smoothedScale /= SMOOTHING_FRAMES;
+	
+	setTransform(smoothedPosition, smoothedRotation, smoothedScale);
+}
+
 void ModelPart::setTransform(glm::vec2 position, float rotation, float scale) {
 	transMatrix = glm::ortho(-windowAspectRatio, windowAspectRatio, -1.0f, 1.0f);
 	transMatrix = glm::translate(transMatrix, glm::vec3(position.x, -position.y, 0.0f) + glm::vec3(posOffset, 0.0f));
@@ -55,7 +80,7 @@ void ModelPart::processFaceData(struct FaceData faceData) {
 	glm::vec2 followDirection = followPosition - bindPosition;
 	glm::vec2 newPosition = bindPosition + (followDirection * factor);
 
-	setTransform(newPosition, faceData.headRotation, faceData.scale);
+	smoothTransform(newPosition, faceData.headRotation, faceData.scale);
 
 	// change textures
 	selectTexture(0);	// if none are triggered, use the first one
diff --git a/src/modelpart.hpp b/src/modelpart.hpp
index 4d14edb..63db13e 100644
--- a/src/modelpart.hpp
+++ b/src/modelpart.hpp
@@ -14,6 +14,9 @@
 #define TRIGGER_NULL		0x00
 #define TRIGGER_MOUTH_OPEN	0x01
 
+// number of frames to average for smoothing
+#define SMOOTHING_FRAMES	4
+
 class ModelPart {
 	GLuint vao;
 
@@ -25,6 +28,11 @@ class ModelPart {
 	glm::mat4 transMatrix = glm::mat4(1.0f);
 
 	bool empty = true;
+
+	glm::vec2 histPositions[SMOOTHING_FRAMES];
+	float histRotations[SMOOTHING_FRAMES];
+	float histScales[SMOOTHING_FRAMES];
+	size_t histI = 0;
 	
 	public:
 		int bind = BIND_NULL;
@@ -47,6 +55,7 @@ class ModelPart {
 		void setBind(std::string bindName);
 		void setFollowTarget(std::string followTarget);
 
+		void smoothTransform(glm::vec2 position, float rotation, float scale);
 		void setTransform(glm::vec2 position, float rotation, float scale);
 
 		void processFaceData(struct FaceData faceData);