diff --git a/cudoku.c b/cudoku.c
index 9d63c97..121a402 100644
--- a/cudoku.c
+++ b/cudoku.c
@@ -35,17 +35,10 @@ unsigned int prepare_bg_rect() {
   return vao;
 }
 
-void draw_bg_rect(Shader shader, unsigned int vao, float x_scale, float y_scale) {
+void draw_bg_rect(Shader shader, unsigned int vao, float* transform) {
   use_shader(shader);
 
-  float mat[4][4] = {
-    {x_scale, 0, 0, 0},
-    {0, y_scale, 0, 0},
-    {0, 0, 1, 0},
-    {0, 0, 0, 1},
-  };
-
-  set_mat4(shader, "transform", (float *)mat);
+  set_mat4(shader, "transform", transform);
 
   glBindVertexArray(vao);
   glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
@@ -54,17 +47,10 @@ void draw_bg_rect(Shader shader, unsigned int vao, float x_scale, float y_scale)
   /* glBindVertexArray(0); */
 }
 
-void draw_bg_lines(Shader shader, float x_scale, float y_scale, float resolution) {
+void draw_bg_lines(Shader shader, float* transform, float resolution) {
   use_shader(shader);
 
-  float mat[4][4] = {
-    {x_scale, 0, 0, 0},
-    {0, y_scale, 0, 0},
-    {0, 0, 1, 0},
-    {0, 0, 0, 1},
-  };
-
-  set_mat4(shader, "transform", (float *)mat);
+  set_mat4(shader, "transform", transform);
   set_float(shader, "resolution", resolution);
 
   glDrawArrays(GL_TRIANGLES, 0, 6);
diff --git a/cudoku.h b/cudoku.h
index 61eacd0..7b97d75 100644
--- a/cudoku.h
+++ b/cudoku.h
@@ -3,5 +3,5 @@
 #include "shader.h"
 
 unsigned int prepare_bg_rect(Shader shader);
-void draw_bg_rect(Shader shader, unsigned int vao, float x_scale, float y_scale);
-void draw_bg_lines(Shader shader, float x_scale, float y_scale, float resolution);
+void draw_bg_rect(Shader shader, unsigned int vao, float* transform);
+void draw_bg_lines(Shader shader, float* transform, float resolution);
diff --git a/main.c b/main.c
index eb6bef1..31e9aa9 100644
--- a/main.c
+++ b/main.c
@@ -68,8 +68,15 @@ int main() {
     glClearColor(0.0, 0.0, 0.0, 1.0);
     glClear(GL_COLOR_BUFFER_BIT);
 
-    draw_bg_rect(board_shader, board_vao, x_scale, y_scale);
-    draw_bg_lines(grid_shader, x_scale, y_scale, width < height ? width : height);
+    float transform[4][4] = {
+      {x_scale, 0, 0, 0},
+      {0, y_scale, 0, 0},
+      {0, 0, 1, 0},
+      {0, 0, 0, 1},
+    };
+
+    draw_bg_rect(board_shader, board_vao, (float *)transform);
+    draw_bg_lines(grid_shader, (float *)transform, width < height ? width : height);
 
     glXSwapBuffers(display, window);
   }