Move push/pop GL state calls

You can place it around your OpenGL code too.

engine/Engine.cpp

@@ -58,6 +58,8 @@ void Engine::create(int screenWidth, int screenHeight, const std::string &name,
             Time::startTimer("d projections");
             if (_useOpenGL) {
                 GLfloat *view = camera->glInvModel();
+                screen->pushGLStates();
+                screen->prepareToGlDrawMesh();
                 for (auto &it : *world) {
                     if (it.second->isVisible()) {
                         GLfloat *model = it.second->glModel();
@@ -66,9 +68,9 @@ void Engine::create(int screenWidth, int screenHeight, const std::string &name,
                         delete[] model;
                     }
                 }
+                screen->popGLStates();
                 delete[] view;
             } else {
-                screen->pushGLStates();
                 // clear triangles from previous frame
                 camera->clear();
                 // project triangles to the camera plane
@@ -81,11 +83,9 @@ void Engine::create(int screenWidth, int screenHeight, const std::string &name,
                 }
 
                 _triPerSec = camera->buffSize() * Time::fps();
-                screen->popGLStates();
             }
             Time::stopTimer("d projections");
 
-            screen->pushGLStates();
             if (Consts::SHOW_FPS_COUNTER) {
                 screen->drawText(std::to_string(Time::fps()) + " fps",
                                  Vec2D(static_cast<double>(screen->width()) - 100.0, 10.0), 25,
@@ -93,7 +93,6 @@ void Engine::create(int screenWidth, int screenHeight, const std::string &name,
             }
             printDebugInfo();
             gui();
-            screen->popGLStates();
         }
 
         screen->display();

engine/Screen.cpp

@@ -112,13 +112,14 @@ void Screen::drawText(const sf::Text &text) {
 }
 
 // OpenGL functions
-void Screen::glDrawMesh(GLfloat *geometry, GLfloat *view, GLfloat *model, size_t count) {
+void Screen::prepareToGlDrawMesh() {
-
     if (!sf::Shader::isAvailable())
     {
         Log::log("Shaders are not available!");
     }
 
+    sf::Shader::bind(NULL);
+
     glEnable(GL_CULL_FACE); // enable culling face
     glCullFace(GL_BACK); // cull faces from back
     glFrontFace(GL_CCW); // vertex order (counter clock wise)
@@ -147,15 +148,20 @@ void Screen::glDrawMesh(GLfloat *geometry, GLfloat *view, GLfloat *model, size_t
     // Enable position and texture coordinates vertex components
     glEnableClientState(GL_VERTEX_ARRAY);
     glEnableClientState(GL_COLOR_ARRAY);
-    glVertexPointer(3, GL_FLOAT, 7 * sizeof(GLfloat), geometry);
-    glColorPointer(4, GL_FLOAT, 7 * sizeof(GLfloat), geometry + 3);
 
     // Disable normal and color vertex components
     glDisableClientState(GL_NORMAL_ARRAY);
     glDisableClientState(GL_TEXTURE_COORD_ARRAY);
 
-    // Apply some transformations
+    // Prepare to apply some transformations
     glMatrixMode(GL_MODELVIEW);
+}
+
+// OpenGL functions
+void Screen::glDrawMesh(GLfloat* geometry, GLfloat* view, GLfloat* model, size_t count) {
+    glVertexPointer(3, GL_FLOAT, 7 * sizeof(GLfloat), geometry);
+    glColorPointer(4, GL_FLOAT, 7 * sizeof(GLfloat), geometry + 3);
+
     glLoadIdentity();
 
     glLoadMatrixf(view);
@@ -163,6 +169,4 @@ void Screen::glDrawMesh(GLfloat *geometry, GLfloat *view, GLfloat *model, size_t
 
     // Draw the mesh
     glDrawArrays(GL_TRIANGLES, 0, count);
-
-    sf::Shader::bind(NULL);
 }

engine/Screen.h

@@ -60,6 +60,8 @@ public:
     void setMouseCursorVisible(bool visible);
 
     // OpenGL functions
+    void prepareToGlDrawMesh();
+    
     void glDrawMesh(GLfloat *geometry, GLfloat *view, GLfloat *model, size_t count);
 
     [[nodiscard]] std::shared_ptr<sf::RenderWindow> renderWindow() { return _window; }

engine/gui/Window.cpp

@@ -18,7 +18,6 @@ void Window::addButton(int x, int y, int w, int h, std::function<void()> click,
 
 void Window::update() {
 
-    _screen->pushGLStates();
     _screen->setTitle(_name);
     _screen->drawSprite(_back);
 
@@ -46,7 +45,6 @@ void Window::update() {
             _screen->drawText(button.text());
         }
     }
-    _screen->popGLStates();
 }
 
 void Window::setBackgroundTexture(const std::string &texture, double sx, double sy, int w, int h) {