diff --git a/src/k3.h b/src/k3.h
index 9e4cfb3..381a835 100644
--- a/src/k3.h
+++ b/src/k3.h
@@ -6,8 +6,13 @@
 #include<cglm/mat4.h>
 #include<cglm/quat.h>
 
+#ifdef k3_MULTITHREAD
+#include<pthread.h>
+#endif
+
 void k3Init();
 void k3Resize(uint16_t width, uint16_t height);
+void k3Update();
 
 enum k3TexType {
 	k3_DIFFUSE, k3_NORMAL, k3_DISPLACEMENT, k3_EMISSION, k3_ROUGHNESS, k3_ALPHA,
diff --git a/src/k3batch.c b/src/k3batch.c
index c2fa228..f3cdd5d 100644
--- a/src/k3batch.c
+++ b/src/k3batch.c
@@ -12,6 +12,8 @@ struct S {
 };
 
 static struct k3Tex *activeTex;
+static float activeBorderRadius;
+
 static size_t SCount, SCapacity;
 static struct S *S;
 
@@ -25,21 +27,33 @@ void k3BatchInit() {
 			"in vec2 a_pos;\n"
 			"in vec2 a_uv;\n"
 			"in vec4 a_color;\n"
+			"in vec2 a_size;\n"
 			"out vec2 v_uv;\n"
 			"out vec4 v_color;\n"
+			"out vec2 v_size;\n"
 			"void main() {\n"
 			"	v_uv = a_uv;\n"
 			"	v_color = a_color;\n"
+			"	v_size = a_size;\n"
 			"	gl_Position = vec4(vec2(a_pos.x / 3600.0, a_pos.y / 2025.0) * 2.0 - 1.0, 0.0, 1.0);\n"
 			"}\n"
 		, NULL), k3ShaderGLSLF(
 			"#version 330\n"
 			"uniform sampler2D u_tex;\n"
 			"uniform float u_texuse;\n"
+			"uniform float u_borderradius;\n"
 			"in vec2 v_uv;\n"
 			"in vec4 v_color;\n"
+			"in vec2 v_size;\n"
 			"out vec4 fragcolor;\n"
 			"void main() {\n"
+			"	vec2 sz = v_size / 2.0;\n"
+			"	vec2 c = abs(v_uv * 2.0 - 1.0);\n"
+			"	c = c * (sz + u_borderradius);\n"
+			"	c = max(c - sz, 0.0);\n"
+			"	if(length(c) > u_borderradius) {\n"
+			"		discard;\n"
+			"	}\n"
 			"	fragcolor = mix(vec4(1, 1, 1, 1), texture2D(u_tex, v_uv), u_texuse) * v_color;\n"
 			"}\n"
 		, NULL), NULL);
@@ -48,10 +62,11 @@ void k3BatchInit() {
 	}
 }
 
-void k3BatchAdd(struct k3Tex *tex, struct k3RectF src, struct k3RectF dst, float rot, vec4 color) {
-	if(activeTex != tex) {
+void k3BatchAdd(struct k3Tex *tex, struct k3RectF src, struct k3RectF dst, float rot, vec4 color, float borderRadius) {
+	if(activeTex != tex || borderRadius != activeBorderRadius) {
 		k3BatchFlush();
 		activeTex = tex;
+		activeBorderRadius = borderRadius;
 	}
 	
 	if(SCount == SCapacity) {
@@ -73,6 +88,8 @@ void k3BatchAdd(struct k3Tex *tex, struct k3RectF src, struct k3RectF dst, float
 }
 
 void k3BatchFlush() {
+	if(!S) return;
+	
 	if(!k3IsCore) {
 		glDisable(GL_NORMALIZE);
 		
@@ -108,89 +125,107 @@ void k3BatchFlush() {
 	if(k3IsCore) {
 		glUseProgram((GLuint) coreProg);
 		
-		float *farr = alloca(SCount * 48 * sizeof(*farr));
+		float *farr = alloca(SCount * 60 * sizeof(*farr));
 		
 		struct S *s = S;
 		for(size_t i = 0; i < SCount; i++) {
-			farr[i * 48 + 0] = s->dst.x;
-			farr[i * 48 + 1] = s->dst.y;
-			farr[i * 48 + 2] = s->src.x;
-			farr[i * 48 + 3] = s->src.y + s->src.h;
-			farr[i * 48 + 4] = s->color[0];
-			farr[i * 48 + 5] = s->color[1];
-			farr[i * 48 + 6] = s->color[2];
-			farr[i * 48 + 7] = s->color[3];
+			farr[i * 60 + 0] = s->dst.x;
+			farr[i * 60 + 1] = s->dst.y;
+			farr[i * 60 + 2] = s->src.x;
+			farr[i * 60 + 3] = s->src.y + s->src.h;
+			farr[i * 60 + 4] = s->color[0];
+			farr[i * 60 + 5] = s->color[1];
+			farr[i * 60 + 6] = s->color[2];
+			farr[i * 60 + 7] = s->color[3];
+			farr[i * 60 + 8] = s->dst.w;
+			farr[i * 60 + 9] = s->dst.h;
 			
-			farr[i * 48 + 8] = s->dst.x + s->dst.w;
-			farr[i * 48 + 9] = s->dst.y;
-			farr[i * 48 + 10] = s->src.x + s->src.w;
-			farr[i * 48 + 11] = s->src.y + s->src.h;
-			farr[i * 48 + 12] = s->color[0];
-			farr[i * 48 + 13] = s->color[1];
-			farr[i * 48 + 14] = s->color[2];
-			farr[i * 48 + 15] = s->color[3];
+			farr[i * 60 + 10] = s->dst.x + s->dst.w;
+			farr[i * 60 + 11] = s->dst.y;
+			farr[i * 60 + 12] = s->src.x + s->src.w;
+			farr[i * 60 + 13] = s->src.y + s->src.h;
+			farr[i * 60 + 14] = s->color[0];
+			farr[i * 60 + 15] = s->color[1];
+			farr[i * 60 + 16] = s->color[2];
+			farr[i * 60 + 17] = s->color[3];
+			farr[i * 60 + 18] = s->dst.w;
+			farr[i * 60 + 19] = s->dst.h;
 			
-			farr[i * 48 + 16] = s->dst.x + s->dst.w;
-			farr[i * 48 + 17] = s->dst.y + s->dst.h;
-			farr[i * 48 + 18] = s->src.x + s->src.w;
-			farr[i * 48 + 19] = s->src.y;
-			farr[i * 48 + 20] = s->color[0];
-			farr[i * 48 + 21] = s->color[1];
-			farr[i * 48 + 22] = s->color[2];
-			farr[i * 48 + 23] = s->color[3];
+			farr[i * 60 + 20] = s->dst.x + s->dst.w;
+			farr[i * 60 + 21] = s->dst.y + s->dst.h;
+			farr[i * 60 + 22] = s->src.x + s->src.w;
+			farr[i * 60 + 23] = s->src.y;
+			farr[i * 60 + 24] = s->color[0];
+			farr[i * 60 + 25] = s->color[1];
+			farr[i * 60 + 26] = s->color[2];
+			farr[i * 60 + 27] = s->color[3];
+			farr[i * 60 + 28] = s->dst.w;
+			farr[i * 60 + 29] = s->dst.h;
 			
-			farr[i * 48 + 24] = s->dst.x;
-			farr[i * 48 + 25] = s->dst.y;
-			farr[i * 48 + 26] = s->src.x;
-			farr[i * 48 + 27] = s->src.y + s->src.h;
-			farr[i * 48 + 28] = s->color[0];
-			farr[i * 48 + 29] = s->color[1];
-			farr[i * 48 + 30] = s->color[2];
-			farr[i * 48 + 31] = s->color[3];
+			farr[i * 60 + 30] = s->dst.x;
+			farr[i * 60 + 31] = s->dst.y;
+			farr[i * 60 + 32] = s->src.x;
+			farr[i * 60 + 33] = s->src.y + s->src.h;
+			farr[i * 60 + 34] = s->color[0];
+			farr[i * 60 + 35] = s->color[1];
+			farr[i * 60 + 36] = s->color[2];
+			farr[i * 60 + 37] = s->color[3];
+			farr[i * 60 + 38] = s->dst.w;
+			farr[i * 60 + 39] = s->dst.h;
 			
-			farr[i * 48 + 32] = s->dst.x + s->dst.w;
-			farr[i * 48 + 33] = s->dst.y + s->dst.h;
-			farr[i * 48 + 34] = s->src.x + s->src.w;
-			farr[i * 48 + 35] = s->src.y;
-			farr[i * 48 + 36] = s->color[0];
-			farr[i * 48 + 37] = s->color[1];
-			farr[i * 48 + 38] = s->color[2];
-			farr[i * 48 + 39] = s->color[3];
+			farr[i * 60 + 40] = s->dst.x + s->dst.w;
+			farr[i * 60 + 41] = s->dst.y + s->dst.h;
+			farr[i * 60 + 42] = s->src.x + s->src.w;
+			farr[i * 60 + 43] = s->src.y;
+			farr[i * 60 + 44] = s->color[0];
+			farr[i * 60 + 45] = s->color[1];
+			farr[i * 60 + 46] = s->color[2];
+			farr[i * 60 + 47] = s->color[3];
+			farr[i * 60 + 48] = s->dst.w;
+			farr[i * 60 + 49] = s->dst.h;
 			
-			farr[i * 48 + 40] = s->dst.x;
-			farr[i * 48 + 41] = s->dst.y + s->dst.h;
-			farr[i * 48 + 42] = s->src.x;
-			farr[i * 48 + 43] = s->src.y;
-			farr[i * 48 + 44] = s->color[0];
-			farr[i * 48 + 45] = s->color[1];
-			farr[i * 48 + 46] = s->color[2];
-			farr[i * 48 + 47] = s->color[3];
+			farr[i * 60 + 50] = s->dst.x;
+			farr[i * 60 + 51] = s->dst.y + s->dst.h;
+			farr[i * 60 + 52] = s->src.x;
+			farr[i * 60 + 53] = s->src.y;
+			farr[i * 60 + 54] = s->color[0];
+			farr[i * 60 + 55] = s->color[1];
+			farr[i * 60 + 56] = s->color[2];
+			farr[i * 60 + 57] = s->color[3];
+			farr[i * 60 + 58] = s->dst.w;
+			farr[i * 60 + 59] = s->dst.h;
 			
 			s++;
 		}
 		
 		glBindBufferARB(GL_ARRAY_BUFFER_ARB, coreVBO);
-		glBufferDataARB(GL_ARRAY_BUFFER_ARB, SCount * 48 * sizeof(*farr), farr, GL_DYNAMIC_DRAW);
+		glBufferDataARB(GL_ARRAY_BUFFER_ARB, SCount * 60 * sizeof(*farr), farr, GL_DYNAMIC_DRAW);
 		
 		glUniform1f(glGetUniformLocation((GLuint) coreProg, "u_texuse"), !!activeTex);
 		
+		glUniform1f(glGetUniformLocation((GLuint) coreProg, "u_borderradius"), activeBorderRadius);
+		
 		GLint aPos = glGetAttribLocation((GLuint) coreProg, "a_pos");
 		GLint aUv = glGetAttribLocation((GLuint) coreProg, "a_uv");
 		GLint aColor = glGetAttribLocation((GLuint) coreProg, "a_color");
+		GLint aSize = glGetAttribLocation((GLuint) coreProg, "a_size");
 		
 		glEnableVertexAttribArray(aPos);
 		glEnableVertexAttribArray(aUv);
 		glEnableVertexAttribArray(aColor);
+		glEnableVertexAttribArray(aSize);
 		
-		glVertexAttribPointer(aPos, 2, GL_FLOAT, GL_FALSE, 32, (void*) 0);
-		glVertexAttribPointer(aUv, 2, GL_FLOAT, GL_FALSE, 32, (void*) 8);
-		glVertexAttribPointer(aColor, 4, GL_FLOAT, GL_FALSE, 32, (void*) 16);
+		glVertexAttribPointer(aPos, 2, GL_FLOAT, GL_FALSE, 40, (void*) 0);
+		glVertexAttribPointer(aUv, 2, GL_FLOAT, GL_FALSE, 40, (void*) 8);
+		glVertexAttribPointer(aColor, 4, GL_FLOAT, GL_FALSE, 40, (void*) 16);
+		glVertexAttribPointer(aSize, 2, GL_FLOAT, GL_FALSE, 40, (void*) 32);
 		
 		glDrawArrays(GL_TRIANGLES, 0, SCount * 6);
 		
 		glDisableVertexAttribArray(aPos);
 		glDisableVertexAttribArray(aUv);
 		glDisableVertexAttribArray(aColor);
+		glDisableVertexAttribArray(aSize);
 	} else {
 		if(GLAD_GL_ARB_shading_language_100) {
 			glUseProgramObjectARB(0);
diff --git a/src/k3batch.h b/src/k3batch.h
index f668772..91b4030 100644
--- a/src/k3batch.h
+++ b/src/k3batch.h
@@ -10,5 +10,5 @@ struct k3RectF {
 	float h;
 };
 
-void k3BatchAdd(struct k3Tex *tex, struct k3RectF src, struct k3RectF dst, float rot, vec4 color);
-void k3BatchFlush();
\ No newline at end of file
+void k3BatchAdd(struct k3Tex *tex, struct k3RectF src, struct k3RectF dst, float rot, vec4 color, float borderRadius);
+void k3BatchFlush();