13 files changed, 842 insertions, 38 deletions

diff --git a/themes/#LeafParticleRender.cpp# b/themes/#LeafParticleRender.cpp#
new file mode 100644
index 0000000..2cb0b35
--- /dev/null
+++ b/themes/#LeafParticleRender.cpp#
@@ -0,0 +1,162 @@
+#include "LeafParticleRender.h"
+#include "Renderer2d.h"
+#include "mathlib.h"
+#include "TreeShape.h"
+#include "types.h"
+#include <math.h>
+
+const int32 verticesPerLeaf = 6; 
+const float32 leafRadius = 3.f;
+const int32 fallChanceMax = 100;
+
+inline void updateLeaf(Renderer2dVertex* vertices, Vector2 position, Vector4 color, float32 scale) {
+    float32 radius = scale * leafRadius;
+    Vector2 bottomLeft = Vector2(-radius, -radius) + position;
+    Vector2 bottomRight = Vector2(radius, -radius) + position;
+    Vector2 topLeft = Vector2(-radius, radius) + position;
+    Vector2 topRight = Vector2(radius, radius) + position;
+
+    vertices[0] = { bottomLeft, color };
+    vertices[1] = { bottomRight, color };
+    vertices[2] = { topLeft, color };
+    vertices[3] = { topLeft, color };
+    vertices[4] = { topRight, color };
+    vertices[5] = { bottomRight, color };
+}
+
+void LeafParticleRender::load(Renderer2d *renderer, TreeShapeLoadResult* lr) {
+    LeafParticleLoadData ld;
+    ld.numLeaves = 256;
+    numLeaves = ld.numLeaves;
+    numVertices = ld.numLeaves * verticesPerLeaf;
+
+    updateData = new LeafParticleUpdateData[numLeaves];
+    vertices = new Renderer2dVertex[numVertices];
+
+    for (int32 leafIdx = 0; leafIdx < numLeaves; leafIdx++) {
+        int32 randomBranch = randomIntBetween(0, lr->numBranches);
+        int32 randomVertex = randomIntBetween(0, 6); // TODO: Manually entering num vertices per branch.
+        updateData[leafIdx].vertexToFollow = &lr->updateData[randomBranch].vertices[randomVertex];
+        updateData[leafIdx].fallChance = randomIntBetween(0, fallChanceMax);
+        updateData[leafIdx].color = Vector4(randomFloatBetween(0.3, 0.9), randomFloatBetween(0.1, 0.6), 0, 1);
+        updateData[leafIdx].vertexPtr = &vertices[leafIdx * verticesPerLeaf];
+        updateData[leafIdx].resetTime = randomFloatBetween(4.f, 6.f);
+    }
+
+    useShader(renderer->shader);
+
+    glGenVertexArrays(1, &vao);
+    glBindVertexArray(vao);
+
+    glGenBuffers(1, &vbo);
+    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+    glBufferData(GL_ARRAY_BUFFER, numVertices * sizeof(Renderer2dVertex), &vertices[0], GL_DYNAMIC_DRAW);
+
+    glEnableVertexAttribArray(renderer->attributes.position);
+    glVertexAttribPointer(renderer->attributes.position, 2, GL_FLOAT, GL_FALSE, sizeof(Renderer2dVertex), (GLvoid *)0);
+
+    glEnableVertexAttribArray(renderer->attributes.color);
+    glVertexAttribPointer(renderer->attributes.color, 4, GL_FLOAT, GL_FALSE, sizeof(Renderer2dVertex), (GLvoid *)offsetof(Renderer2dVertex, color));
+
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindVertexArray(0);
+}
+
+void LeafParticleRender::update(float32 dtSeconds) {
+    elapsedTimeSeconds += dtSeconds;
+
+    // Every time the fallIntervalSeconds passes, we remove one leaf
+    // from the tree and send it barrelling towards the earth.
+    int32 fallRoll;
+    bool didGenerateFall = false;
+    if (elapsedTimeSeconds >= fallIntervalSeconds) {
+        fallRoll = randomIntBetween(0, fallChanceMax);
+        didGenerateFall = true;
+        elapsedTimeSeconds = 0;
+    }
+
+    for (int32 leafIdx = 0; leafIdx < numLeaves; leafIdx++) {
+        auto updateDataItem = &updateData[leafIdx];
+
+        if (didGenerateFall) {
+            if (updateDataItem->state == LeafParticleState::OnTree && updateDataItem->fallChance == fallRoll) {
+                updateDataItem->state = LeafParticleState::Falling;
+                updateDataItem->fallPosition = updateDataItem->vertexToFollow->position;
+                updateDataItem->fallVerticalVelocity = -randomFloatBetween(15.f, 25.f);
+                updateDataItem->fallHorizontalFrequency = randomFloatBetween(3.f, 5.f);
+            }
+        }
+
+        switch (updateDataItem->state) {
+        case (LeafParticleState::Remerging): {
+            updateDataItem->timeElapsedSeconds += dtSeconds;
+
+            if (updateDataItem->timeElapsedSeconds >= updateDataItem->resetTime) {
+                updateDataItem->timeElapsedSeconds = 0.f;
+                updateDataItem->state = LeafParticleState::OnTree;
+                updateDataItem->color.w = 1.f;
+                updateDataItem->scale = 1.f;
+            }
+            else {
+                updateDataItem->color.w = (updateDataItem->timeElapsedSeconds / updateDataItem->resetTime);
+                updateDataItem->scale = (updateDataItem->timeElapsedSeconds / updateDataItem->resetTime);
+            }
+
+            updateLeaf(updateDataItem->vertexPtr, updateDataItem->vertexToFollow->position, updateDataItem->color, updateDataItem->scale);
+            break;
+        }
+        case (LeafParticleState::OnGround): {
+            updateDataItem->timeElapsedSeconds += dtSeconds;
+
+            if (updateDataItem->timeElapsedSeconds >= updateDataItem->resetTime) {
+                updateDataItem->timeElapsedSeconds = 0.f;
+                updateDataItem->color.w = 0.f;
+                updateDataItem->state = LeafParticleState::Remerging;
+            }
+            else {
+                updateDataItem->color.w = 1.f - (updateDataItem->timeElapsedSeconds / updateDataItem->resetTime);
+                updateLeaf(updateDataItem->vertexPtr, updateDataItem->fallPosition, updateDataItem->color, updateDataItem->scale);
+            }
+            break;
+        }
+        case (LeafParticleState::Falling): {
+            updateDataItem->timeElapsedSeconds += dtSeconds;
+            const float32 xPosUpdate = cosf(updateDataItem->fallHorizontalFrequency * updateDataItem->timeElapsedSeconds);
+            updateDataItem->fallPosition.x += xPosUpdate;
+            updateDataItem->fallPosition.y += updateDataItem->fallVerticalVelocity * dtSeconds;
+            if (updateDataItem->fallPosition.y <= 50.f) { // TODO: Hardcoded ground for now
+                updateDataItem->fallPosition.y = 50.f;
+                updateDataItem->state = LeafParticleState::OnGround;
+                updateDataItem->timeElapsedSeconds = 0;
+                updateDataItem->resetTime = randomFloatBetween(2.f, 5.f); // TODO: Hardcoded reset interval
+            }
+            updateLeaf(updateDataItem->vertexPtr, updateDataItem->fallPosition, updateDataItem->color, updateDataItem->scale);
+            break;
+        }
+        case (LeafParticleState::OnTree): {
+            updateLeaf(updateDataItem->vertexPtr, updateDataItem->vertexToFollow->position, updateDataItem->color, updateDataItem->scale);
+            break;
+        }
+        }
+    }
+}
+
+void LeafParticleRender::render(Renderer2d *renderer) {
+    setShaderMat4(renderer->uniforms.model, model);
+
+    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+    glBufferSubData(GL_ARRAY_BUFFER, 0, numVertices * sizeof(Renderer2dVertex), &vertices[0]);
+
+    glBindVertexArray(vao);
+    glDrawArrays(GL_TRIANGLES, 0, numVertices);
+    glBindVertexArray(0);
+}
+
+void LeafParticleRender::unload() {
+    glDeleteVertexArrays(1, &vao);
+    glDeleteBuffers(1, &vbo);
+    delete [] vertices;
+	delete [] updateData;
+
+    elapsedTimeSeconds = 0;
+}
\ No newline at end of file
diff --git a/themes/LeafParticleRender.cpp b/themes/LeafParticleRender.cpp
index 2fc89ac..e1ed1ec 100644
--- a/themes/LeafParticleRender.cpp
+++ b/themes/LeafParticleRender.cpp
@@ -16,12 +16,12 @@ inline void updateLeaf(Renderer2dVertex* vertices, Vector2 position, Vector4 col
     Vector2 topLeft = Vector2(-radius, radius) + position;
     Vector2 topRight = Vector2(radius, radius) + position;
 
-    vertices[0] = { bottomLeft, color };
-    vertices[1] = { bottomRight, color };
-    vertices[2] = { topLeft, color };
-    vertices[3] = { topLeft, color };
-    vertices[4] = { topRight, color };
-    vertices[5] = { bottomRight, color };
+    vertices[0] = { bottomLeft, color, Mat4x4() };
+    vertices[1] = { bottomRight, color, Mat4x4() };
+    vertices[2] = { topLeft, color, Mat4x4() };
+    vertices[3] = { topLeft, color, Mat4x4() };
+    vertices[4] = { topRight, color, Mat4x4() };
+    vertices[5] = { bottomRight, color, Mat4x4() };
 }
 
 void LeafParticleRender::load(Renderer2d *renderer, TreeShapeLoadResult* lr) {
@@ -58,6 +58,11 @@ void LeafParticleRender::load(Renderer2d *renderer, TreeShapeLoadResult* lr) {
     glEnableVertexAttribArray(renderer->attributes.color);
     glVertexAttribPointer(renderer->attributes.color, 4, GL_FLOAT, GL_FALSE, sizeof(Renderer2dVertex), (GLvoid *)offsetof(Renderer2dVertex, color));
 
+	for (int32 idx = 0; idx < 4; idx++) {
+		glEnableVertexAttribArray(renderer->attributes.vMatrix + idx);
+		glVertexAttribPointer(renderer->attributes.vMatrix + idx, 4, GL_FLOAT, GL_FALSE, sizeof(Renderer2dVertex), (GLvoid *)(offsetof(Renderer2dVertex, vMatrix) + (idx * 16)));
+	}
+	
     glBindBuffer(GL_ARRAY_BUFFER, 0);
     glBindVertexArray(0);
 }
@@ -158,4 +163,4 @@ void LeafParticleRender::unload() {
     delete [] vertices;
 
     elapsedTimeSeconds = 0;
-}
\ No newline at end of file
+}
diff --git a/themes/List.h b/themes/List.h
new file mode 100644
index 0000000..00a466a
--- /dev/null
+++ b/themes/List.h
@@ -0,0 +1,222 @@
+#pragma once
+#include <cstdlib>
+#include <cstring>
+#include "Logger.h"
+
+#define FOREACH(list)												\
+	for (size_t idx = 0; idx < list.numElements; idx++) \
+		if (auto value = list.getValue(idx)) \
+		
+
+template <typename T>
+struct List {
+	T* data = nullptr;
+	size_t capacity = 0;
+	size_t numElements = 0;
+	bool growDynamically = true;
+
+	void allocate(size_t size);
+	void add(T* element);
+	void add(T& element);
+	void add(T&& element);
+	bool grow(size_t newSize);
+	void set(T* value, size_t index);
+	void remove(size_t index);
+	void clear();
+	void deallocate();
+	bool isEmpty() {
+		return data == nullptr || numElements == 0;
+	}
+	T* getValue(int index) const;
+	T& operator[](int idx) const;
+	void binarySort(int (*f)(T *first, T* second));
+	void setFromArray(T* arry, int size) {
+	    allocate(size);
+		memcpy(data, arry, size * sizeof(T));
+		numElements = size;
+	}
+	void remove(int index) {
+		if (index >= numElements) {
+			logger_error("Cannot remove element at index: %d", index);
+			return;
+		}
+
+		
+		if (index == numElements - 1) {
+			numElements--;
+			return;
+		}
+		
+		memmove(data[index], data[index + 1], sizeof(T) * (numElements - index));
+		numElements--;
+	}
+};
+
+template <typename T>
+void List<T>::allocate(size_t size) {
+	if (size == 0 || size == capacity) {
+		numElements = 0;
+		return;
+	}
+
+	if (data != nullptr) {
+		deallocate();
+	}
+
+	data = static_cast<T*>(malloc(sizeof(T) * size));
+	capacity = size;
+	numElements = 0;
+}
+
+template <typename T>
+bool List<T>::grow(size_t newSize) {
+	if (!growDynamically) {
+		return false;
+	}
+
+	if (newSize == 0) {
+		return false;
+	}
+
+	T* newData = static_cast<T*>(malloc(sizeof(T) * newSize));
+
+	if (data != nullptr) {
+		memcpy(newData, data, numElements * sizeof(T));
+		delete data;
+	}
+
+	data = newData;
+	capacity = newSize;
+	return true;
+}
+
+template <typename T>
+void List<T>::set(T* value, size_t index) {
+	if (index >= capacity && !grow(index * 2)) {
+		return;
+	}
+
+	memcpy(&data[index], value, sizeof(T));
+}
+
+template <typename T>
+void List<T>::add(T* element) {
+	if (data == nullptr) {
+		allocate(2);
+	}
+
+	if (element == nullptr) {
+		logger_error("Element not defined");
+		return;
+	}
+
+	size_t newNumElements = numElements + 1;
+	if (newNumElements > capacity) {
+		if (!grow(2 * capacity)) {
+			logger_error("Trying to add to list but unable to grow the array");
+			return;
+		}
+	}
+
+	memcpy(&data[numElements], element, sizeof(T));
+	numElements = newNumElements;
+}
+
+template <typename T>
+void List<T>::add(T& element) {
+	if (data == nullptr) {
+		allocate(2);
+	}
+
+	size_t newNumElements = numElements + 1;
+	if (newNumElements > capacity) {
+		if (!grow(2 * capacity)) {
+			logger_error("Trying to add to list but unable to grow the array");
+			return;
+		}
+	}
+
+	memcpy(&data[numElements], &element, sizeof(T));
+	numElements = newNumElements;
+}
+
+template <typename T>
+void List<T>::add(T&& element) {
+	if (data == nullptr) {
+		allocate(2);
+	}
+
+	size_t newNumElements = numElements + 1;
+	if (newNumElements > capacity) {
+		if (!grow(2 * capacity)) {
+			logger_error("Trying to add to list but unable to grow the array");
+			return;
+		}
+	}
+
+	memcpy(&data[numElements], &element, sizeof(T));
+	numElements = newNumElements;
+}
+
+template <typename T>
+void List<T>::remove(size_t idx) {
+	if (idx >= numElements) {
+		logger_error("Index is outside of the list: %d >= %d", idx, numElements);
+		return;
+	}
+
+	for (; idx < numElements - 1; idx++) {
+		data[idx] = data[idx + 1];
+	}
+
+	numElements--;
+}
+
+template <typename T>
+void List<T>::deallocate() {
+	if (data != nullptr) {
+		free(data);
+		data = nullptr;
+	}
+
+	capacity = 0;
+	numElements = 0;
+}
+
+template <typename T>
+void List<T>::clear() {
+	numElements = 0;
+}
+
+template <typename T>
+T* List<T>::getValue(int idx) const {
+	return &data[idx];
+}
+
+template <typename T>
+T& List<T>::operator[](int idx) const {
+	return data[idx];
+}
+
+template <typename T>
+void List<T>::binarySort(int (*f)(T *first, T* second)) {
+	if (data == nullptr) {
+		return;
+	}
+
+	for (size_t idx = 0; idx < numElements - 1; idx++) {
+		int minIdx = idx;
+		T firstValue = data[idx];
+
+		for (int innerIdx = idx + 1; innerIdx < numElements; innerIdx++) {\
+			T secondValue = data[innerIdx];
+			if (f(&firstValue, &secondValue) > 0) {
+				minIdx= innerIdx;
+			}
+		}
+
+		T temp = data[minIdx];
+		memmove(&data[minIdx], &data[idx], sizeof(T));
+		memmove(&data[idx], &temp, sizeof(T));
+	}
+}
diff --git a/themes/Logger.cpp b/themes/Logger.cpp
new file mode 100644
index 0000000..1068d88
--- /dev/null
+++ b/themes/Logger.cpp
@@ -0,0 +1,123 @@
+#include "Logger.h"
+#include <chrono>
+#include <cstdarg>
+#include <cstdio>
+
+namespace Logger {
+    LogLevel gLogLevel = LogLevel_Debug;
+    FILE* gFilePointer = NULL;
+
+    void initialize(LoggerOptions options) {
+        setLevel(options.level);
+        if (options.logToFile) {
+#ifdef WIN32
+            fopen_s(&gFilePointer, options.filePath, "a");
+#else
+            gFilePointer = fopen(options.filePath, "a");
+#endif
+        }
+    }
+
+    void setLevel(LogLevel level) {
+        gLogLevel = level;
+    }
+
+    LogLevel getLevel() {
+        return gLogLevel;
+    }
+
+    void printHeader(const char* levelStr, const char* fileName, int lineNumber) {
+        time_t t = time(0);
+        tm now;
+#ifdef WIN32
+        localtime_s(&now, &t);
+#else
+        now = *localtime(&t);
+#endif
+
+        printf("%s:%d [%d-%d-%d %d:%d:%d] %s: ", fileName, lineNumber, (now.tm_year + 1900), (now.tm_mon + 1), now.tm_mday, now.tm_hour, now.tm_min, now.tm_sec, levelStr);
+        if (gFilePointer != NULL) {
+            fprintf(gFilePointer, "[%d-%d-%d %d:%d:%d] %s: ", (now.tm_year + 1900), (now.tm_mon + 1), now.tm_mday, now.tm_hour, now.tm_min, now.tm_sec, levelStr);
+        }
+    }
+
+    void logInternal(const char* file, int lineNumber,LogLevel level, const char* format, va_list args) {
+        if (level < gLogLevel) {
+            return;
+        }
+
+	
+        const char* levelStr;
+        switch (level) {
+        case LogLevel_Debug:
+            levelStr = "Debug";
+            break;
+        case LogLevel_Info:
+            levelStr = "Info";
+            break;
+        case LogLevel_Warn:
+            levelStr = "Warning";
+            break;
+        case LogLevel_Error:
+            levelStr = "Error";
+            break;
+        default:
+            levelStr = "Unknown";
+            break;
+        }
+
+	if (gFilePointer != NULL) {
+	    va_list fileArgs;
+	    va_copy(fileArgs, args);
+	    vfprintf(gFilePointer, format, fileArgs);
+	    fprintf(gFilePointer, "\n");
+	}
+
+        printHeader(levelStr, file, lineNumber);
+
+        vprintf(format, args);
+        printf("\n");
+    }
+
+    void doLog(const char* file, int lineNumber,LogLevel level, const char* format, ...) {
+        va_list args;
+        va_start(args, format);
+        logInternal(file, lineNumber, level, format, args);
+        va_end(args);
+    }
+
+    void doDebug(const char* file, int lineNumber,const char* format, ...) {
+        va_list args;
+        va_start(args, format);
+        logInternal(file, lineNumber, LogLevel_Debug, format, args);
+        va_end(args);
+    }
+
+    void doInfo(const char* file, int lineNumber,const char* format, ...) {
+        va_list args;
+        va_start(args, format);
+        logInternal(file, lineNumber, LogLevel_Info, format, args);
+        va_end(args);
+    }
+
+    void doWarning(const char* file, int lineNumber,const char* format, ...) {
+        va_list args;
+        va_start(args, format);
+        logInternal(file, lineNumber, LogLevel_Warn, format, args);
+        va_end(args);
+    }
+
+    void doError(const char* file, int lineNumber,const char* format, ...) {
+        va_list args;
+        va_start(args, format);
+        logInternal(file, lineNumber, LogLevel_Error, format, args);
+        va_end(args);
+    }
+
+    void free() {
+        if (gFilePointer) {
+            fclose(gFilePointer);
+	    gFilePointer = NULL;
+        }
+    }
+}
diff --git a/themes/Logger.h b/themes/Logger.h
new file mode 100644
index 0000000..7596b6f
--- /dev/null
+++ b/themes/Logger.h
@@ -0,0 +1,43 @@
+#ifndef LOGGER_H
+#define LOGGER_H
+
+#include <cstring>
+
+enum LogLevel {
+    LogLevel_Debug = 0,
+    LogLevel_Info = 1,
+    LogLevel_Warn = 2,
+    LogLevel_Error = 3
+};
+
+struct LoggerOptions {
+    LogLevel level = LogLevel_Debug;
+    bool logToFile = false;
+    const char* filePath = "debug.log";
+};
+
+namespace Logger {
+    void initialize(LoggerOptions options);
+    void setLevel(LogLevel level);
+    LogLevel getLevel();
+    void doLog(const char* file, int lineNumber, LogLevel level, const char* format, ...);
+    void doDebug(const char* file, int lineNumber, const char* format, ...);
+    void doInfo(const char* file, int lineNumber, const char* format, ...);
+    void doWarning(const char* file, int lineNumber, const char* format, ...);
+    void doError(const char* file, int lineNumber, const char* format, ...);
+    void free();
+};
+
+#if WIN32
+#define __FILENAME__ (strrchr(__FILE__, '\\') ? strrchr(__FILE__, '\\') + 1 : __FILE__)
+#else
+#define __FILENAME__ (strrchr(__FILE__, '/') ? strrchr(__FILE__, '/') + 1 : __FILE__)
+#endif
+
+#define logger_log(level, format, ...) Logger::doLog(__FILENAME__, __LINE__, level, format, ## __VA_ARGS__)
+#define logger_debug(format, ...) Logger::doDebug(__FILENAME__, __LINE__, format, ## __VA_ARGS__)
+#define logger_info(format, ...) Logger::doInfo(__FILENAME__, __LINE__, format, ## __VA_ARGS__)
+#define logger_warning(format, ...) Logger::doWarning(__FILENAME__, __LINE__, format, ## __VA_ARGS__)
+#define logger_error(format, ...) Logger::doError(__FILENAME__, __LINE__, format, ## __VA_ARGS__)
+
+#endif
diff --git a/themes/Renderer2d.cpp b/themes/Renderer2d.cpp
index a58ad86..d81b97b 100644
--- a/themes/Renderer2d.cpp
+++ b/themes/Renderer2d.cpp
@@ -9,11 +9,12 @@
 const char* renderer2dVertexShader = 
 "attribute vec2 position; \n"
 "attribute vec4 color; \n"
+"attribute mat4 vMatrix; \n"
 "uniform mat4 projection; \n"
 "uniform mat4 model; \n"
 "varying lowp vec4 VertexColor; \n"
 "void main() { \n"
-"    vec4 fragmentPosition = projection * model * vec4(position.x, position.y, 0, 1); \n"
+"    vec4 fragmentPosition = projection * model * vMatrix * vec4(position.x, position.y, 0, 1); \n"
 "    gl_Position = fragmentPosition; \n"
 "    VertexColor = color; \n"
 "}";
@@ -44,6 +45,7 @@ void Renderer2d::load(WebglContext* inContext) {
 	useShader(shader);
 	attributes.position = getShaderAttribute(shader, "position");
 	attributes.color = getShaderAttribute(shader, "color");
+	attributes.vMatrix = getShaderAttribute(shader, "vMatrix");
 	uniforms.projection = getShaderUniform(shader, "projection");
 	uniforms.model = getShaderUniform(shader, "model");
 	projection = Mat4x4().getOrthographicMatrix(0, context->width, 0, context->height);
@@ -90,6 +92,11 @@ void Renderer2dShape::load(Renderer2dVertex* inVertices, uint32 inNumVertices, R
 	glEnableVertexAttribArray(renderer->attributes.color);
 	glVertexAttribPointer(renderer->attributes.color, 4, GL_FLOAT, GL_FALSE, sizeof(Renderer2dVertex), (GLvoid *)offsetof(Renderer2dVertex, color));
 
+	for (int32 idx = 0; idx < 4; idx++) {
+			glEnableVertexAttribArray(renderer->attributes.vMatrix + idx);
+			glVertexAttribPointer(renderer->attributes.vMatrix + idx, 4, GL_FLOAT, GL_FALSE, sizeof(Renderer2dVertex), (GLvoid *)(offsetof(Renderer2dVertex, vMatrix) + (idx * 16)));
+	}
+	
 	glBindBuffer(GL_ARRAY_BUFFER, 0);
 	glBindVertexArray(0);
 }
diff --git a/themes/Renderer2d.h b/themes/Renderer2d.h
index cbdf4d4..8630169 100644
--- a/themes/Renderer2d.h
+++ b/themes/Renderer2d.h
@@ -16,6 +16,7 @@ struct Renderer2d {
 	struct {
 		int32 position;
 		int32 color;
+		int32 vMatrix;
 	} attributes;
 
 	struct {
@@ -31,6 +32,7 @@ struct Renderer2d {
 struct Renderer2dVertex {
 	Vector2 position;
 	Vector4 color;
+	Mat4x4 vMatrix;
 };
 
 struct Renderer2dShape {
diff --git a/themes/Snowflake.cpp b/themes/Snowflake.cpp
index 54654f0..3c9afa4 100644
--- a/themes/Snowflake.cpp
+++ b/themes/Snowflake.cpp
@@ -1,26 +1,146 @@
 #include "Snowflake.h"
+#include "Renderer2d.h"
+#include "mathlib.h"
+#include "List.h"
+
+const Vector4 snowColor = Vector4(1.0, 0.98, 0.98, 1);
+
+inline void generateSnowflakeShape(List<Renderer2dVertex>* vertices, int32 numArms, float32 radius) {
+	float32 dx = ((2 * PI) / numArms) / 3.0;
+	for (int32 centerIdx = 0; centerIdx < (3 * numArms); centerIdx+=3) {
+	    float32 degreeStart = dx * centerIdx;
+		float32 degreeEnd = dx * (centerIdx + 1);
+
+		float32 cosStart = cosf(degreeStart);
+		float32 cosEnd = cosf(degreeEnd);
+
+		float32 sinStart = sinf(degreeStart);
+		float32 sinEnd = sinf(degreeEnd);
+
+		Vector2 leftEnd = Vector2(radius * cosStart, radius * sinStart);
+		Vector2 rightEnd = Vector2(radius * cosEnd, radius * sinEnd);
+		Vector2 diff = (rightEnd - leftEnd) / 2.0;
+		Vector2 leftStart = Vector2(-diff.x, -diff.y);
+		Vector2 rightStart = diff;
+
+		vertices->add({ leftStart, snowColor, Mat4x4() });
+		vertices->add({ leftEnd, snowColor, Mat4x4() });
+		vertices->add({ rightEnd, snowColor, Mat4x4() });
+		vertices->add({ rightEnd, snowColor, Mat4x4() });
+		vertices->add({ rightStart, snowColor, Mat4x4() });
+		vertices->add({ leftStart, snowColor, Mat4x4() });
+	}
+}
+
+inline void initFlake(SnowflakeParticleRenderer* renderer, SnowflakeUpdateData* ud) {
+	ud->vtxIdx = renderer->vertices.numElements;
+	generateSnowflakeShape(&renderer->vertices, 6, randomFloatBetween(8.f, 24.f);
+	ud->numVertices = renderer->vertices.numElements - ud->vtxIdx;
+}
+
+inline void spawnFlake(SnowflakeParticleRenderer* renderer, SnowflakeUpdateData* ud) {
+	ud->velocity = Vector2(randomFloatBetween(-10, 10), randomFloatBetween(-100, -85));
+	ud->position = Vector2(randomFloatBetween(0, renderer->xMax), randomFloatBetween(renderer->yMax, renderer->yMax + 256));
+}
+
+inline void findAndSpawnNextFlake(SnowflakeParticleRenderer* renderer) {
+    do {
+	    renderer->endIndex++;
+
+		if (renderer->endIndex >= renderer->numSnowflakes)
+			renderer->endIndex = 0;
+	} while (renderer->updateData[renderer->endIndex].onGround);
+
+	spawnFlake(renderer, &renderer->updateData[renderer->endIndex]);
+}
 
 void SnowflakeParticleRenderer::load(SnowflakeLoadParameters params, Renderer2d* renderer) {
-	updateData = new SnowflakeUpdateData[maxSnowflakes];
-    renderData = new SnowflakeRenderData[maxSnowflakes];
-	activeIndex = 0;
+	startIndex = 0;
+	spawnIntervalSeconds = params.spawnIntervalSeconds;
+	endIndex = params.initialSnowflakeCount;
+	numSnowflakes = params.maxSnowflakes;
+
+	updateData = new SnowflakeUpdateData[params.maxSnowflakes];
 
-	for (int32 s = 0; s < maxSnowflakes; s++) {
+	xMax = static_cast<float32>(renderer->context->width);
+    yMax = static_cast<float32>(renderer->context->height);
+	
+	// Initialize each snow flake with its shape
+	for (int32 s = 0; s < numSnowflakes; s++) {
 		auto ud = &updateData[s];
-		auto rd = &renderData[s];
+	    initFlake(this, ud);
+
+		if (s < endIndex) {
+			spawnFlake(this, ud);
+		}
+	}
+
+	useShader(renderer->shader);
+
+    glGenVertexArrays(1, &vao);
+    glBindVertexArray(vao);
+
+    glGenBuffers(1, &vbo);
+    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+    glBufferData(GL_ARRAY_BUFFER, vertices.numElements * sizeof(Renderer2dVertex), &vertices.data[0], GL_DYNAMIC_DRAW);
+
+    glEnableVertexAttribArray(renderer->attributes.position);
+    glVertexAttribPointer(renderer->attributes.position, 2, GL_FLOAT, GL_FALSE, sizeof(Renderer2dVertex), (GLvoid *)0);
+
+    glEnableVertexAttribArray(renderer->attributes.color);
+    glVertexAttribPointer(renderer->attributes.color, 4, GL_FLOAT, GL_FALSE, sizeof(Renderer2dVertex), (GLvoid *)offsetof(Renderer2dVertex, color));
 
-		ud->velocity = params->flakeV0;
+	for (int32 idx = 0; idx < 4; idx++) {
+		int32 offset = (4 * sizeof(float32)) * idx;
+		glEnableVertexAttribArray(renderer->attributes.vMatrix + idx);
+		glVertexAttribPointer(renderer->attributes.vMatrix + idx,
+							  4,
+							  GL_FLOAT,
+							  GL_FALSE,
+							  sizeof(Renderer2dVertex),
+							  (GLvoid *)(offsetof(Renderer2dVertex, vMatrix) + offset));
+		//glVertexAttribDivisor(renderer->attributes.vMatrix + idx, 1);
 	}
+
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindVertexArray(0);
 }
 
 void SnowflakeParticleRenderer::update(float32 dtSeconds) {
-	
+	timeUntilNextSpawnSeconds -= dtSeconds;
+	if (timeUntilNextSpawnSeconds < 0) {
+		timeUntilNextSpawnSeconds = spawnIntervalSeconds;
+		findAndSpawnNextFlake(this);
+	}
+
+	for (int32 s = startIndex; s < endIndex; s++) {
+		SnowflakeUpdateData* ud = &updateData[s];
+		ud->position += ud->velocity * dtSeconds;
+
+		Mat4x4 m = Mat4x4().translateByVec2(ud->position);
+		for (int32 v = ud->vtxIdx; v < (ud->vtxIdx + ud->numVertices); v++) {
+		    vertices.data[v].vMatrix = m;
+		}
+	}
 }
 
 void SnowflakeParticleRenderer::render(Renderer2d* renderer) {
+	auto startVertex = &updateData[startIndex];
+	auto endVertex = &updateData[endIndex];
+	int32 numVertices = (endVertex->vtxIdx + endVertex->numVertices) - startVertex->vtxIdx;
+	setShaderMat4(renderer->uniforms.model, model);
 
+    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+    glBufferSubData(GL_ARRAY_BUFFER, 0, numVertices * sizeof(Renderer2dVertex), &vertices.data[startVertex->vtxIdx]);
+
+    glBindVertexArray(vao);
+    glDrawArrays(GL_TRIANGLES, 0, numVertices);
+    glBindVertexArray(0);
 }
 
 void SnowflakeParticleRenderer::unload() {
-
+	glDeleteVertexArrays(1, &vao);
+    glDeleteBuffers(1, &vbo);
+	vertices.deallocate();
+	delete [] updateData;
 }
diff --git a/themes/Snowflake.h b/themes/Snowflake.h
index 09b05db..08f1c0c 100644
--- a/themes/Snowflake.h
+++ b/themes/Snowflake.h
@@ -1,36 +1,50 @@
 #include "types.h"
 #include "mathlib.h"
+#include "List.h"
 
 struct Renderer2d;
-struct SnowflakeUpdateData;
-struct SnowflakeRenderData;
+struct Renderer2dVertex;
 
 struct SnowflakeLoadParameters {
-	int32 maxSnowflakes = 10000;
+	int32 maxSnowflakes = 1000;
+	int32 initialSnowflakeCount = 100;
 	float32 rateOfSnowfall = 0.1f;
-    Vector3 flakeV0 = { 0, 1, 0 };
+    Vector2 flakeV0 = { 0, 1 };
 	float32 flakeSize = 5.f;
 	float32 flakeSizeDeviation = 1.f;
 	Vector4 snowColor = { 0.8, 0.8, 0.8, 1.0 };
+	float32 spawnIntervalSeconds = 0.3;
+};
+
+struct SnowflakeUpdateData {
+	Vector2 v0;
+	Vector2 velocity;
+	Vector2 position;
+	float32 rotation;
+	bool onGround = false;
+
+	int32 vtxIdx = 0;
+	int32 numVertices = 0;
 };
 
 struct SnowflakeParticleRenderer {
-	int32 activeIndex = 0;
+	float32 xMax = 0;
+	float32 yMax = 0;
+	float32 spawnIntervalSeconds = 0.3;
+	int32 startIndex = 0;
+	int32 endIndex = 0;
+	int32 numSnowflakes = 0;
     Vector3 windSpeed = { 0, 0, 0 };
 	SnowflakeUpdateData* updateData;
-	SnowflakeRenderData* renderData;
+	float32 timeUntilNextSpawnSeconds = 0;;
+
+	uint32 vao;
+	uint32 vbo;
+	Mat4x4 model;
+	List<Renderer2dVertex> vertices;
 	
-	void load(SnowflakeLoadParameters params, Renderer2d* renderer);o
+	void load(SnowflakeLoadParameters params, Renderer2d* renderer);
 	void update(float32 dtSeconds);
 	void render(Renderer2d* renderer);
 	void unload();
 };
-
-struct SnowflakeUpdateData {
-	Vector3 velocity;
-	Vector3 position;
-};
-
-struct SnowflakeRenderData {
-	
-};
diff --git a/themes/TreeShape.cpp b/themes/TreeShape.cpp
index 797ceca..08170ea 100644
--- a/themes/TreeShape.cpp
+++ b/themes/TreeShape.cpp
@@ -59,6 +59,12 @@ TreeShapeLoadResult TreeShape::load(Renderer2d* renderer) {
     glEnableVertexAttribArray(renderer->attributes.color);
     glVertexAttribPointer(renderer->attributes.color, 4, GL_FLOAT, GL_FALSE, sizeof(Renderer2dVertex), (GLvoid *)offsetof(Renderer2dVertex, color));
 
+	for (int32 idx = 0; idx < 4; idx++) {
+		glEnableVertexAttribArray(renderer->attributes.vMatrix + idx);
+		glVertexAttribPointer(renderer->attributes.vMatrix + idx, 4, GL_FLOAT, GL_FALSE, sizeof(Renderer2dVertex), (GLvoid *)(offsetof(Renderer2dVertex, vMatrix) + (idx * 16)));
+		glVertexAttribDivisor(renderer->attributes.vMatrix + idx, 1);
+	}
+
     glBindBuffer(GL_ARRAY_BUFFER, 0);
     glBindVertexArray(0);
 
diff --git a/themes/dist/output.js b/themes/dist/output.js
index 9a83997..9eb0f70 100644
--- a/themes/dist/output.js
+++ b/themes/dist/output.js
@@ -1835,6 +1835,82 @@ var ASM_CONSTS = {
       return demangleAll(js);
     }
 
+  function _tzset_impl() {
+      var currentYear = new Date().getFullYear();
+      var winter = new Date(currentYear, 0, 1);
+      var summer = new Date(currentYear, 6, 1);
+      var winterOffset = winter.getTimezoneOffset();
+      var summerOffset = summer.getTimezoneOffset();
+  
+      // Local standard timezone offset. Local standard time is not adjusted for daylight savings.
+      // This code uses the fact that getTimezoneOffset returns a greater value during Standard Time versus Daylight Saving Time (DST).
+      // Thus it determines the expected output during Standard Time, and it compares whether the output of the given date the same (Standard) or less (DST).
+      var stdTimezoneOffset = Math.max(winterOffset, summerOffset);
+  
+      // timezone is specified as seconds west of UTC ("The external variable
+      // `timezone` shall be set to the difference, in seconds, between
+      // Coordinated Universal Time (UTC) and local standard time."), the same
+      // as returned by stdTimezoneOffset.
+      // See http://pubs.opengroup.org/onlinepubs/009695399/functions/tzset.html
+      HEAP32[((__get_timezone())>>2)] = stdTimezoneOffset * 60;
+  
+      HEAP32[((__get_daylight())>>2)] = Number(winterOffset != summerOffset);
+  
+      function extractZone(date) {
+        var match = date.toTimeString().match(/\(([A-Za-z ]+)\)$/);
+        return match ? match[1] : "GMT";
+      };
+      var winterName = extractZone(winter);
+      var summerName = extractZone(summer);
+      var winterNamePtr = allocateUTF8(winterName);
+      var summerNamePtr = allocateUTF8(summerName);
+      if (summerOffset < winterOffset) {
+        // Northern hemisphere
+        HEAP32[((__get_tzname())>>2)] = winterNamePtr;
+        HEAP32[(((__get_tzname())+(4))>>2)] = summerNamePtr;
+      } else {
+        HEAP32[((__get_tzname())>>2)] = summerNamePtr;
+        HEAP32[(((__get_tzname())+(4))>>2)] = winterNamePtr;
+      }
+    }
+  function _tzset() {
+      // TODO: Use (malleable) environment variables instead of system settings.
+      if (_tzset.called) return;
+      _tzset.called = true;
+      _tzset_impl();
+    }
+  function _localtime_r(time, tmPtr) {
+      _tzset();
+      var date = new Date(HEAP32[((time)>>2)]*1000);
+      HEAP32[((tmPtr)>>2)] = date.getSeconds();
+      HEAP32[(((tmPtr)+(4))>>2)] = date.getMinutes();
+      HEAP32[(((tmPtr)+(8))>>2)] = date.getHours();
+      HEAP32[(((tmPtr)+(12))>>2)] = date.getDate();
+      HEAP32[(((tmPtr)+(16))>>2)] = date.getMonth();
+      HEAP32[(((tmPtr)+(20))>>2)] = date.getFullYear()-1900;
+      HEAP32[(((tmPtr)+(24))>>2)] = date.getDay();
+  
+      var start = new Date(date.getFullYear(), 0, 1);
+      var yday = ((date.getTime() - start.getTime()) / (1000 * 60 * 60 * 24))|0;
+      HEAP32[(((tmPtr)+(28))>>2)] = yday;
+      HEAP32[(((tmPtr)+(36))>>2)] = -(date.getTimezoneOffset() * 60);
+  
+      // Attention: DST is in December in South, and some regions don't have DST at all.
+      var summerOffset = new Date(date.getFullYear(), 6, 1).getTimezoneOffset();
+      var winterOffset = start.getTimezoneOffset();
+      var dst = (summerOffset != winterOffset && date.getTimezoneOffset() == Math.min(winterOffset, summerOffset))|0;
+      HEAP32[(((tmPtr)+(32))>>2)] = dst;
+  
+      var zonePtr = HEAP32[(((__get_tzname())+(dst ? 4 : 0))>>2)];
+      HEAP32[(((tmPtr)+(40))>>2)] = zonePtr;
+  
+      return tmPtr;
+    }
+  function ___localtime_r(a0,a1
+  ) {
+  return _localtime_r(a0,a1);
+  }
+
   function _abort() {
       abort('native code called abort()');
     }
@@ -3017,6 +3093,10 @@ var ASM_CONSTS = {
       GLctx.currentProgram = program;
     }
 
+  function _glVertexAttribDivisor(index, divisor) {
+      GLctx['vertexAttribDivisor'](index, divisor);
+    }
+
   function _glVertexAttribPointer(index, size, type, normalized, stride, ptr) {
       var cb = GL.currentContext.clientBuffers[index];
       if (!GLctx.currentArrayBufferBinding) {
@@ -3083,6 +3163,7 @@ function intArrayToString(array) {
 
 
 var asmLibraryArg = {
+  "__localtime_r": ___localtime_r,
   "abort": _abort,
   "emscripten_get_element_css_size": _emscripten_get_element_css_size,
   "emscripten_memcpy_big": _emscripten_memcpy_big,
@@ -3130,6 +3211,7 @@ var asmLibraryArg = {
   "glShaderSource": _glShaderSource,
   "glUniformMatrix4fv": _glUniformMatrix4fv,
   "glUseProgram": _glUseProgram,
+  "glVertexAttribDivisor": _glVertexAttribDivisor,
   "glVertexAttribPointer": _glVertexAttribPointer,
   "setTempRet0": _setTempRet0,
   "time": _time
@@ -3142,12 +3224,27 @@ var ___wasm_call_ctors = Module["___wasm_call_ctors"] = createExportWrapper("__w
 var _main = Module["_main"] = createExportWrapper("main");
 
 /** @type {function(...*):?} */
+var _free = Module["_free"] = createExportWrapper("free");
+
+/** @type {function(...*):?} */
+var _malloc = Module["_malloc"] = createExportWrapper("malloc");
+
+/** @type {function(...*):?} */
 var ___errno_location = Module["___errno_location"] = createExportWrapper("__errno_location");
 
 /** @type {function(...*):?} */
 var _fflush = Module["_fflush"] = createExportWrapper("fflush");
 
 /** @type {function(...*):?} */
+var __get_tzname = Module["__get_tzname"] = createExportWrapper("_get_tzname");
+
+/** @type {function(...*):?} */
+var __get_daylight = Module["__get_daylight"] = createExportWrapper("_get_daylight");
+
+/** @type {function(...*):?} */
+var __get_timezone = Module["__get_timezone"] = createExportWrapper("_get_timezone");
+
+/** @type {function(...*):?} */
 var stackSave = Module["stackSave"] = createExportWrapper("stackSave");
 
 /** @type {function(...*):?} */
@@ -3172,12 +3269,6 @@ var _emscripten_stack_get_end = Module["_emscripten_stack_get_end"] = function()
 };
 
 /** @type {function(...*):?} */
-var _malloc = Module["_malloc"] = createExportWrapper("malloc");
-
-/** @type {function(...*):?} */
-var _free = Module["_free"] = createExportWrapper("free");
-
-/** @type {function(...*):?} */
 var dynCall_jiji = Module["dynCall_jiji"] = createExportWrapper("dynCall_jiji");
 
 
diff --git a/themes/dist/output.wasm b/themes/dist/output.wasm
index 495ea67..427f834 100755
--- a/themes/dist/output.wasm
+++ b/themes/dist/output.wasm
diff --git a/themes/main.cpp b/themes/main.cpp
index 8ca7fc4..8f908a3 100644
--- a/themes/main.cpp
+++ b/themes/main.cpp
@@ -5,6 +5,7 @@
 #include "types.h"
 #include "TreeShape.h"
 #include "LeafParticleRender.h"
+#include "Snowflake.h"
 
 enum Theme {
 	Default = 0,
@@ -23,6 +24,8 @@ struct AutumnTheme {
 };
 
 struct WinterTheme {
+	SnowflakeParticleRenderer spr;
+	
 	void load(Renderer2d* renderer);
 	void update(float32 dtSeconds);
 	void render(Renderer2d* renderer);
@@ -167,13 +170,19 @@ void AutumnTheme::unload()  {
 // -- Winter theme
 void WinterTheme::load(Renderer2d* renderer) {
     renderer->clearColor = Vector4(200, 229, 239, 255).toNormalizedColor();
+	SnowflakeLoadParameters lp;
+	lp.spawnIntervalSeconds = 0.05;
+	spr.load(lp, renderer);
 }
 
 void WinterTheme::update(float32 dtSeconds) {
+	spr.update(dtSeconds);
 }
 
 void WinterTheme::render(Renderer2d* renderer) {
+	spr.render(renderer);
 }
 
 void WinterTheme::unload()  {
+	spr.unload();
 }