cleanup: Fix comparison between pointer and 0 (instead of nullptr)

panda/src/dxgsg9/dxShaderContext9.cxx

@@ -693,7 +693,7 @@ update_shader_texture_bindings(DXShaderContext9 *prev, GSG *gsg) {
         continue;
       }
 
-      if (spec._suffix != 0) {
+      if (spec._suffix != nullptr) {
         // The suffix feature is inefficient.  It is a temporary hack.
         tex = tex->load_related(spec._suffix);
       }

panda/src/dxgsg9/wdxGraphicsBuffer9.cxx

@@ -266,7 +266,7 @@ rebuild_bitplanes() {
 
   // Decide how big the bitplanes should be.
 
-  if ((_host != 0)&&(_creation_flags & GraphicsPipe::BF_size_track_host)) {
+  if (_host != nullptr && (_creation_flags & GraphicsPipe::BF_size_track_host) != 0) {
     if (_host->get_size() != _size) {
       set_size_and_recalc(_host->get_x_size(),
                           _host->get_y_size());
@@ -739,7 +739,7 @@ bool wdxGraphicsBuffer9::
 open_buffer() {
 
   // GSG creationinitialization.
-  if (_gsg == 0) {
+  if (_gsg == nullptr) {
     // The code below doesn't support creating a GSG on the fly.  Just error
     // out for now.  _dxgsg = new DXGraphicsStateGuardian9(_engine, _pipe);
     // _gsg = _dxgsg;

panda/src/dxgsg9/wdxGraphicsWindow9.cxx

@@ -261,7 +261,7 @@ open_window() {
   static ConfigVariableBool always_discard_device("always-discard-device", true);
   bool discard_device = always_discard_device;
 
-  if (_gsg == 0) {
+  if (_gsg == nullptr) {
     _dxgsg = new DXGraphicsStateGuardian9(_engine, _pipe);
     _gsg = _dxgsg;
   } else {

panda/src/glstuff/glCgShaderContext_src.cxx

@@ -1113,14 +1113,14 @@ update_shader_texture_bindings(ShaderContext *prev) {
       continue;
     }
 
-    if (spec._suffix != 0) {
+    if (spec._suffix != nullptr) {
       // The suffix feature is inefficient.  It is a temporary hack.
-      if (tex == 0) {
+      if (tex == nullptr) {
         continue;
       }
       tex = tex->load_related(spec._suffix);
     }
-    if ((tex == 0) || (tex->get_texture_type() != spec._desired_type)) {
+    if (tex == nullptr || tex->get_texture_type() != spec._desired_type) {
       continue;
     }
 

panda/src/glstuff/glGraphicsBuffer_src.cxx

@@ -360,7 +360,7 @@ check_fbo() {
 void CLP(GraphicsBuffer)::
 rebuild_bitplanes() {
   check_host_valid();
-  if (_gsg == 0) {
+  if (_gsg == nullptr) {
     return;
   }
 
@@ -1661,7 +1661,7 @@ close_buffer() {
 
   check_host_valid();
 
-  if (_gsg == 0) {
+  if (_gsg == nullptr) {
     return;
   }
 
@@ -1824,7 +1824,7 @@ unregister_shared_depth_buffer(GraphicsOutput *graphics_output) {
  */
 void CLP(GraphicsBuffer)::
 report_my_errors(int line, const char *file) {
-  if (_gsg == 0) {
+  if (_gsg == nullptr) {
     GLenum error_code = glGetError();
     if (error_code != GL_NO_ERROR) {
       GLCAT.error() << file << ", line " << line << ": GL error " << (int)error_code << "\n";

panda/src/gobj/material.I

@@ -58,7 +58,7 @@ INLINE Material::
  */
 INLINE Material *Material::
 get_default() {
-  if (_default == 0) {
+  if (_default == nullptr) {
     _default = new Material("default");
   }
   return _default;

panda/src/wgldisplay/wglGraphicsBuffer.cxx

@@ -157,7 +157,7 @@ bind_texture_to_pbuffer() {
   if (tex_index >= 0) {
     const RenderTexture &rt = cdata->_textures[tex_index];
     Texture *tex = rt._texture;
-    if ((_pbuffer_bound != 0)&&(_pbuffer_bound != tex)) {
+    if (_pbuffer_bound != nullptr && _pbuffer_bound != tex) {
       _pbuffer_bound->release(wglgsg->get_prepared_objects());
       _pbuffer_bound = 0;
     }
@@ -188,7 +188,7 @@ bind_texture_to_pbuffer() {
     }
     _pbuffer_bound = tex;
   } else {
-    if (_pbuffer_bound != 0) {
+    if (_pbuffer_bound != nullptr) {
       _pbuffer_bound->release(wglgsg->get_prepared_objects());
       _pbuffer_bound = 0;
     }
@@ -292,7 +292,7 @@ open_buffer() {
   // GSG creationinitialization.
 
   wglGraphicsStateGuardian *wglgsg;
-  if (_gsg == 0) {
+  if (_gsg == nullptr) {
     // There is no old gsg.  Create a new one.
     wglgsg = new wglGraphicsStateGuardian(_engine, _pipe, nullptr);
     wglgsg->choose_pixel_format(_fb_properties, true);
@@ -355,16 +355,16 @@ open_buffer() {
  */
 void wglGraphicsBuffer::
 release_pbuffer() {
-  if (_gsg == 0) {
+  if (_gsg == nullptr) {
     return;
   }
 
   wglGraphicsStateGuardian *wglgsg;
   DCAST_INTO_V(wglgsg, _gsg);
 
-  if (_pbuffer_bound != 0) {
+  if (_pbuffer_bound != nullptr) {
     _pbuffer_bound->release(wglgsg->get_prepared_objects());
-    _pbuffer_bound = 0;
+    _pbuffer_bound.clear();
   }
   wglGraphicsPipe::wgl_make_current(0, 0, nullptr);
   if (_pbuffer_dc) {
@@ -420,7 +420,7 @@ rebuild_bitplanes() {
   // Determine what pbuffer attributes are needed for currently-applicable
   // textures.
 
-  if ((_host != 0)&&(_creation_flags & GraphicsPipe::BF_size_track_host)) {
+  if (_host != nullptr && (_creation_flags & GraphicsPipe::BF_size_track_host) != 0) {
     if (_host->get_size() != _size) {
       set_size_and_recalc(_host->get_x_size(),
                           _host->get_y_size());

panda/src/wgldisplay/wglGraphicsWindow.cxx

@@ -200,7 +200,7 @@ open_window() {
   // GSG creationinitialization.
 
   wglGraphicsStateGuardian *wglgsg;
-  if (_gsg == 0) {
+  if (_gsg == nullptr) {
     // There is no old gsg.  Create a new one.
     wglgsg = new wglGraphicsStateGuardian(_engine, _pipe, nullptr);
     wglgsg->choose_pixel_format(_fb_properties, false);