diff --git a/main.c b/main.c
index 46703a3..c37ac2d 100644
--- a/main.c
+++ b/main.c
@@ -15,6 +15,9 @@ static double FrameTime = 1.0 / INITIAL_FPS;
 
 static double PerformancePeriod;
 
+const int WIDTH = 640;
+const int HEIGHT = 480;
+
 static double GetTime( void )
 {
     return PerformancePeriod * SDL_GetPerformanceCounter();
@@ -30,15 +33,13 @@ static void SetTitle ( SDL_Window *window )
 int main( int argc, char* argv[] )
 {
     _glWindows_t glW;
-    const int WIDTH = 640;
-    const int HEIGHT = 480;
     int delayThreshold = 2;
     int r, g, b, alpha_s, depth_s, stencil_s, dbuffer, glVersionMa, glVersionMi, glAccel, glProfile = 0;
     double sleepTime = 0;
     double timeCounter = 0;
     bool loopShouldStop = false;
 
-    SDL_SetHint(SDL_HINT_RENDER_VSYNC, 0);
+    /* SDL_SetHint(SDL_HINT_RENDER_VSYNC, 0); */
     if (!SDL_Init(SDL_INIT_VIDEO)) {
         SDL_LogCritical(SDL_LOG_CATEGORY_ASSERT, "SDL_Init failed: %s", SDL_GetError());
         exit(EXIT_FAILURE);
@@ -76,9 +77,7 @@ int main( int argc, char* argv[] )
 
     SetTitle(glW.window);
 
-    SDL_HideCursor();
-
-    glewExperimental = GL_TRUE;
+    glewExperimental = GL_FALSE;
     GLenum err = glewInit();
     if (err != GLEW_OK) {
         SDL_LogCritical(SDL_LOG_CATEGORY_ASSERT, "glewInit: %s", glewGetErrorString(err));
@@ -103,8 +102,9 @@ int main( int argc, char* argv[] )
     SDL_LogVerbose(SDL_LOG_CATEGORY_RENDER, "Red size: %d, Green size: %d, Blue size: %d, Alpha size: %d, Depth size: %d, Stencil size: %d, DoubleBuffer: %d",
                    r, g, b, alpha_s, depth_s, stencil_s, dbuffer);
 
-    SDL_GL_SetSwapInterval(0);
+    SDL_GL_SetSwapInterval(1);
     startShaderProg();
+    _matrix(WIDTH, HEIGHT);
 
     while (!loopShouldStop) {
         SDL_Event e;
@@ -135,7 +135,7 @@ int main( int argc, char* argv[] )
 
         _GLBuffer();
         if (!SDL_GL_SwapWindow(glW.window)) {
-            SDL_LogCritical(SDL_LOG_CATEGORY_ASSERT, "SDL_GL_SwapWwindow: %s", SDL_GetError());
+            SDL_LogCritical(SDL_LOG_CATEGORY_ASSERT, "SDL_GL_SwapWindow: %s", SDL_GetError());
             exit(EXIT_FAILURE);
         }
 
diff --git a/opengl.c b/opengl.c
index 0285c39..1b2e2dd 100644
--- a/opengl.c
+++ b/opengl.c
@@ -33,6 +33,27 @@ void resizeWindow ( int width, int height )
     glViewport(0, 0, (GLsizei)width, (GLsizei)height);
 }
 
+void _matrix ( int width, int height )
+{
+    float n = 1.0f; // near
+    float f = 3.0f; // far
+    float fov = toRad(90); // 90 or 65 for console
+    float aspect = width / (float) height;
+    float t = n * tanf (fov / 2.0f);
+    float r = t * aspect;
+
+    float projMatr[] = {
+        n/r, 0,   0,              0,
+        0,   n/t, 0,              0,
+        0,   0,   (f+n)/(n-f),   -1,
+        0,   0,   2.0f*n*f/(n-f), 0
+    }; // it's not rows, it's columns, 'GL_FALSE'
+    SDL_LogVerbose(SDL_LOG_CATEGORY_RENDER, "n=%.1f f=%.1f fov=%.2f aspect=%.2f t=%.2f r=%.2f\n", n, f, fov, aspect, t, r);
+    glUseProgram(sp.program);
+    glUniformMatrix4fv(sp.projMatrLoc, 1, GL_FALSE, projMatr);
+    glUseProgram(0);
+}
+
 GLuint createShader ( const char *shaderFile, GLenum shaderType )
 {
     const char *strShaderType;
diff --git a/opengl.h b/opengl.h
index 4409338..a100ac6 100644
--- a/opengl.h
+++ b/opengl.h
@@ -17,6 +17,7 @@ typedef struct {
 GLuint createShader ( const char *shaderFile, GLenum shaderType );
 void createProgram ( GLuint *shaders, int len );
 void resizeWindow ( int width, int height );
+void _matrix ( int width, int height );
 void createBuffer ( void );
 void startShaderProg ( void );
 void _GLBuffer( void );