Tidy up HeadlessView

5 files changed, 110 insertions, 96 deletions

diff --git a/include/mbgl/platform/default/headless_display.hpp b/include/mbgl/platform/default/headless_display.hpp
index 08c423c587..bf67e3c3b3 100644
--- a/include/mbgl/platform/default/headless_display.hpp
+++ b/include/mbgl/platform/default/headless_display.hpp
@@ -15,8 +15,8 @@ public:
 #endif
 
 #if MBGL_USE_GLX
-    Display *x_display = nullptr;
-    GLXFBConfig *fb_configs = nullptr;
+    Display *xDisplay = nullptr;
+    GLXFBConfig *fbConfigs = nullptr;
 #endif
 };
 
diff --git a/include/mbgl/platform/default/headless_view.hpp b/include/mbgl/platform/default/headless_view.hpp
index 9d8acf70f7..a521cff547 100644
--- a/include/mbgl/platform/default/headless_view.hpp
+++ b/include/mbgl/platform/default/headless_view.hpp
@@ -46,19 +46,19 @@ private:
     float pixelRatio_;
 
 #if MBGL_USE_CGL
-    CGLContextObj gl_context;
+    CGLContextObj glContext;
 #endif
 
 #if MBGL_USE_GLX
-    Display *x_display = nullptr;
-    GLXFBConfig *fb_configs = nullptr;
-    GLXContext gl_context = 0;
-    GLXPbuffer glx_pbuffer = 0;
+    Display *xDisplay = nullptr;
+    GLXFBConfig *fbConfigs = nullptr;
+    GLXContext glContext = 0;
+    GLXPbuffer glxPbuffer = 0;
 #endif
 
     GLuint fbo = 0;
-    GLuint fbo_depth_stencil = 0;
-    GLuint fbo_color = 0;
+    GLuint fboDepthStencil = 0;
+    GLuint fboColor = 0;
 };
 
 }
diff --git a/platform/default/glfw_view.cpp b/platform/default/glfw_view.cpp
index 32b7e44ece..7cfb132133 100644
--- a/platform/default/glfw_view.cpp
+++ b/platform/default/glfw_view.cpp
@@ -65,7 +65,6 @@ void GLFWView::initialize(mbgl::Map *map_) {
     glfwSetScrollCallback(window, scroll);
     glfwSetKeyCallback(window, key);
 
-
     const std::string extensions = (char *)glGetString(GL_EXTENSIONS);
     {
         using namespace mbgl;
diff --git a/platform/default/headless_display.cpp b/platform/default/headless_display.cpp
index ada48b8648..40cc0640a9 100644
--- a/platform/default/headless_display.cpp
+++ b/platform/default/headless_display.cpp
@@ -18,31 +18,35 @@ HeadlessDisplay::HeadlessDisplay() {
 
     GLint num;
     CGLError error = CGLChoosePixelFormat(attributes, &pixelFormat, &num);
-    if (error) {
-        fprintf(stderr, "Error pixel format: %s\n", CGLErrorString(error));
+    if (error != kCGLNoError) {
+        throw std::runtime_error(std::string("Error choosing pixel format:") + CGLErrorString(error) + "\n");
+        return;
+    }
+    if (num <= 0) {
+        throw std::runtime_error("No pixel formats found.");
         return;
     }
 #endif
 
 #if MBGL_USE_GLX
     if (!XInitThreads()) {
-        throw std::runtime_error("Failed to XInitThreads");
+        throw std::runtime_error("Failed to XInitThreads.");
     }
 
-    x_display = XOpenDisplay(nullptr);
-    if (x_display == nullptr) {
-        throw std::runtime_error("Failed to open X display");
+    xDisplay = XOpenDisplay(nullptr);
+    if (xDisplay == nullptr) {
+        throw std::runtime_error("Failed to open X display.");
     }
 
-    const char *extensions = (char *)glXQueryServerString(x_display, DefaultScreen(x_display), GLX_EXTENSIONS);
+    const char *extensions = (char *)glXQueryServerString(xDisplay, DefaultScreen(xDisplay), GLX_EXTENSIONS);
     if (!extensions) {
-        throw std::runtime_error("Cannot read GLX extensions");
+        throw std::runtime_error("Cannot read GLX extensions.");
     }
     if (!strstr(extensions,"GLX_SGIX_fbconfig")) {
-        throw std::runtime_error("Extension GLX_SGIX_fbconfig was not found");
+        throw std::runtime_error("Extension GLX_SGIX_fbconfig was not found.");
     }
     if (!strstr(extensions, "GLX_SGIX_pbuffer")) {
-        throw std::runtime_error("Cannot find glXCreateContextAttribsARB");
+        throw std::runtime_error("Cannot find glXCreateContextAttribsARB.");
     }
 
     // We're creating a dummy pbuffer anyway that we're not using.
@@ -52,9 +56,12 @@ HeadlessDisplay::HeadlessDisplay() {
     };
 
     int configs = 0;
-    fb_configs = glXChooseFBConfig(x_display, DefaultScreen(x_display), pixelFormat, &configs);
+    fbConfigs = glXChooseFBConfig(xDisplay, DefaultScreen(xDisplay), pixelFormat, &configs);
+    if (fbConfigs == nullptr) {
+        throw std::runtime_error("Failed to glXChooseFBConfig.");
+    }
     if (configs <= 0) {
-        throw std::runtime_error("No Framebuffer configurations");
+        throw std::runtime_error("No Framebuffer configurations.");
     }
 #endif
 }
@@ -65,10 +72,9 @@ HeadlessDisplay::~HeadlessDisplay() {
 #endif
 
 #if MBGL_USE_GLX
-    XFree(fb_configs);
-    XCloseDisplay(x_display);
+    XFree(fbConfigs);
+    XCloseDisplay(xDisplay);
 #endif
 }
 
 }
-
diff --git a/platform/default/headless_view.cpp b/platform/default/headless_view.cpp
index 5b95c76026..c84651c2e9 100644
--- a/platform/default/headless_view.cpp
+++ b/platform/default/headless_view.cpp
@@ -7,6 +7,7 @@
 #include <sstream>
 #include <string>
 #include <cstring>
+#include <cassert>
 
 #if MBGL_USE_GLX
 #ifdef GLX_ARB_create_context
@@ -23,7 +24,7 @@ CGLProc CGLGetProcAddress(const char *proc) {
     if (!framework) {
         framework = CFBundleGetBundleWithIdentifier(CFSTR("com.apple.opengl"));
         if (!framework) {
-            throw std::runtime_error("Failed to load OpenGL.framework");
+            throw std::runtime_error("Failed to load OpenGL framework.");
         }
     }
 
@@ -59,16 +60,25 @@ void HeadlessView::loadExtensions() {
         gl::DeleteVertexArrays = (gl::PFNGLDELETEVERTEXARRAYSPROC)CGLGetProcAddress("glDeleteVertexArraysAPPLE");
         gl::GenVertexArrays = (gl::PFNGLGENVERTEXARRAYSPROC)CGLGetProcAddress("glGenVertexArraysAPPLE");
         gl::IsVertexArray = (gl::PFNGLISVERTEXARRAYPROC)CGLGetProcAddress("glIsVertexArrayAPPLE");
+        assert(gl::BindVertexArray != nullptr);
+        assert(gl::DeleteVertexArrays != nullptr);
+        assert(gl::GenVertexArrays != nullptr);
+        assert(gl::IsVertexArray != nullptr);
     }
 #endif
 #ifdef MBGL_USE_GLX
     if (extensions.find("GL_ARB_vertex_array_object") != std::string::npos) {
-        gl::BindVertexArray = (gl::PFNGLBINDVERTEXARRAYPROC)glXGetProcAddress((const GLubyte *)"glBindVertexArrayARB");
-        gl::DeleteVertexArrays = (gl::PFNGLDELETEVERTEXARRAYSPROC)glXGetProcAddress((const GLubyte *)"glDeleteVertexArraysARB");
-        gl::GenVertexArrays = (gl::PFNGLGENVERTEXARRAYSPROC)glXGetProcAddress((const GLubyte *)"glGenVertexArraysARB");
-        gl::IsVertexArray = (gl::PFNGLISVERTEXARRAYPROC)glXGetProcAddress((const GLubyte *)"glIsVertexArrayARB");
+        gl::BindVertexArray = (gl::PFNGLBINDVERTEXARRAYPROC)glXGetProcAddress((const GLubyte *)"glBindVertexArray");
+        gl::DeleteVertexArrays = (gl::PFNGLDELETEVERTEXARRAYSPROC)glXGetProcAddress((const GLubyte *)"glDeleteVertexArrays");
+        gl::GenVertexArrays = (gl::PFNGLGENVERTEXARRAYSPROC)glXGetProcAddress((const GLubyte *)"glGenVertexArrays");
+        gl::IsVertexArray = (gl::PFNGLISVERTEXARRAYPROC)glXGetProcAddress((const GLubyte *)"glIsVertexArray");
+        assert(gl::BindVertexArray != nullptr);
+        assert(gl::DeleteVertexArrays != nullptr);
+        assert(gl::GenVertexArrays != nullptr);
+        assert(gl::IsVertexArray != nullptr);
     }
 #endif
+
     make_inactive();
 }
 
@@ -78,7 +88,7 @@ void HeadlessView::loadExtensions() {
 
 // These are all of the OpenGL Core profile version that we know about.
 struct core_profile_version { int major, minor; };
-static const core_profile_version core_profile_versions[] = {
+static const core_profile_version coreProfileVersions[] = {
     {4, 5},
     {4, 4},
     {4, 3},
@@ -93,33 +103,33 @@ static const core_profile_version core_profile_versions[] = {
 };
 
 GLXContext createCoreProfile(Display *dpy, GLXFBConfig fbconfig) {
-    static bool context_creation_failed = false;
+    static bool contextCreationFailed = false;
     GLXContext ctx = 0;
 
     // Set the Error Handler to avoid crashing the program when the context creation fails.
     // It is expected that some context creation attempts fail, e.g. because the OpenGL
     // implementation does not support the version we're requesting.
-    int (*previous_error_handler)(Display *, XErrorEvent *) = XSetErrorHandler([](Display *, XErrorEvent *) {
-        context_creation_failed = true;
+    int (*previousErrorHandler)(Display *, XErrorEvent *) = XSetErrorHandler([](Display *, XErrorEvent *) {
+        contextCreationFailed = true;
         return 0;
     });
 
     // Try to create core profiles from the highest known version on down.
-    for (int i = 0; !ctx && core_profile_versions[i].major; i++) {
-        context_creation_failed = false;
-        const int context_flags[] = {
-            GLX_CONTEXT_MAJOR_VERSION_ARB, core_profile_versions[i].major,
-            GLX_CONTEXT_MINOR_VERSION_ARB, core_profile_versions[i].minor,
+    for (int i = 0; !ctx && coreProfileVersions[i].major; i++) {
+        contextCreationFailed = false;
+        const int contextFlags[] = {
+            GLX_CONTEXT_MAJOR_VERSION_ARB, coreProfileVersions[i].major,
+            GLX_CONTEXT_MINOR_VERSION_ARB, coreProfileVersions[i].minor,
             0
         };
-        ctx = glXCreateContextAttribsARB(dpy, fbconfig, 0, True, context_flags);
-        if (context_creation_failed) {
+        ctx = glXCreateContextAttribsARB(dpy, fbconfig, 0, True, contextFlags);
+        if (contextCreationFailed) {
             ctx = 0;
         }
     }
 
     // Restore the old error handler.
-    XSetErrorHandler(previous_error_handler);
+    XSetErrorHandler(previousErrorHandler);
     return ctx;
 }
 #endif
@@ -127,14 +137,14 @@ GLXContext createCoreProfile(Display *dpy, GLXFBConfig fbconfig) {
 
 void HeadlessView::createContext() {
 #if MBGL_USE_CGL
-    CGLError error = CGLCreateContext(display_->pixelFormat, NULL, &gl_context);
-    if (error) {
-        throw std::runtime_error("Error creating GL context object\n");
+    CGLError error = CGLCreateContext(display_->pixelFormat, NULL, &glContext);
+    if (error != kCGLNoError) {
+        throw std::runtime_error(std::string("Error creating GL context object:") + CGLErrorString(error) + "\n");
     }
 
-    error = CGLEnable(gl_context, kCGLCEMPEngine);
-    if (error != kCGLNoError ) {
-        throw std::runtime_error("Error enabling OpenGL multithreading\n");
+    error = CGLEnable(glContext, kCGLCEMPEngine);
+    if (error != kCGLNoError) {
+        throw std::runtime_error(std::string("Error enabling OpenGL multithreading:") + CGLErrorString(error) + "\n");
     }
 #endif
 
@@ -145,39 +155,39 @@ void HeadlessView::createContext() {
     }
 #endif
 
-    x_display = display_->x_display;
-    fb_configs = display_->fb_configs;
+    xDisplay = display_->xDisplay;
+    fbConfigs = display_->fbConfigs;
 
 #ifdef GLX_ARB_create_context
     if (glXCreateContextAttribsARB) {
         // Try to create a core profile context.
-        gl_context = createCoreProfile(x_display, fb_configs[0]);
+        glContext = createCoreProfile(xDisplay, fbConfigs[0]);
     }
 #endif
 
-    if (!gl_context) {
+    if (!glContext) {
         // Try to create a legacy context
-        gl_context = glXCreateNewContext(x_display, fb_configs[0], GLX_RGBA_TYPE, 0, True);
-        if (gl_context) {
-            if (!glXIsDirect(x_display, gl_context)) {
-                glXDestroyContext(x_display, gl_context);
-                gl_context = 0;
+        glContext = glXCreateNewContext(xDisplay, fbConfigs[0], GLX_RGBA_TYPE, 0, True);
+        if (glContext) {
+            if (!glXIsDirect(xDisplay, glContext)) {
+                glXDestroyContext(xDisplay, glContext);
+                glContext = 0;
             }
         }
     }
 
-    if (gl_context == 0) {
-        throw std::runtime_error("Error creating GL context object");
+    if (glContext == 0) {
+        throw std::runtime_error("Error creating GL context object.");
     }
 
     // Create a dummy pbuffer. We will render to framebuffers anyway, but we need a pbuffer to
     // activate the context.
-    int pbuffer_attributes[] = {
+    int pbufferAttributes[] = {
         GLX_PBUFFER_WIDTH, 8,
         GLX_PBUFFER_HEIGHT, 8,
         0
     };
-    glx_pbuffer = glXCreatePbuffer(x_display, fb_configs[0], pbuffer_attributes);
+    glxPbuffer = glXCreatePbuffer(xDisplay, fbConfigs[0], pbufferAttributes);
 #endif
 }
 
@@ -194,35 +204,35 @@ void HeadlessView::resize(uint16_t width, uint16_t height, float pixelRatio) {
     make_active();
 
     // Create depth/stencil buffer
-    glGenRenderbuffersEXT(1, &fbo_depth_stencil);
-    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo_depth_stencil);
+    glGenRenderbuffersEXT(1, &fboDepthStencil);
+    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fboDepthStencil);
     glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH24_STENCIL8_EXT, w, h);
     glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, 0);
 
-    glGenRenderbuffersEXT(1, &fbo_color);
-    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo_color);
+    glGenRenderbuffersEXT(1, &fboColor);
+    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fboColor);
     glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGBA8, w, h);
     glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, 0);
 
     glGenFramebuffersEXT(1, &fbo);
     glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo);
 
-    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_RENDERBUFFER_EXT, fbo_color);
-    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER_EXT, fbo_depth_stencil);
+    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_RENDERBUFFER_EXT, fboColor);
+    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER_EXT, fboDepthStencil);
 
     GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
 
     if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
         std::stringstream error("Couldn't create framebuffer: ");
         switch (status) {
-            case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT: (error << "incomplete attachment\n"); break;
-            case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT: error << "incomplete missing attachment\n"; break;
-            case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT: error << "incomplete dimensions\n"; break;
-            case GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT: error << "incomplete formats\n"; break;
-            case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT: error << "incomplete draw buffer\n"; break;
-            case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT: error << "incomplete read buffer\n"; break;
-            case GL_FRAMEBUFFER_UNSUPPORTED: error << "unsupported\n"; break;
-            default: error << "other\n"; break;
+            case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT: (error << "incomplete attachment.\n"); break;
+            case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT: error << "incomplete missing attachment.\n"; break;
+            case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT: error << "incomplete dimensions.\n"; break;
+            case GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT: error << "incomplete formats.\n"; break;
+            case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT: error << "incomplete draw buffer.\n"; break;
+            case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT: error << "incomplete read buffer.\n"; break;
+            case GL_FRAMEBUFFER_UNSUPPORTED: error << "unsupported.\n"; break;
+            default: error << "othe.r\n"; break;
         }
         throw std::runtime_error(error.str());
     }
@@ -262,14 +272,14 @@ void HeadlessView::clear_buffers() {
         fbo = 0;
     }
 
-    if (fbo_color) {
-        glDeleteTextures(1, &fbo_color);
-        fbo_color = 0;
+    if (fboColor) {
+        glDeleteTextures(1, &fboColor);
+        fboColor = 0;
     }
 
-    if (fbo_depth_stencil) {
-        glDeleteRenderbuffersEXT(1, &fbo_depth_stencil);
-        fbo_depth_stencil = 0;
+    if (fboDepthStencil) {
+        glDeleteRenderbuffersEXT(1, &fboDepthStencil);
+        fboDepthStencil = 0;
     }
 
     make_inactive();
@@ -279,16 +289,16 @@ HeadlessView::~HeadlessView() {
     clear_buffers();
 
 #if MBGL_USE_CGL
-    CGLDestroyContext(gl_context);
+    CGLDestroyContext(glContext);
 #endif
 
 #if MBGL_USE_GLX
-    if (glx_pbuffer) {
-        glXDestroyPbuffer(x_display, glx_pbuffer);
-        glx_pbuffer = 0;
+    if (glxPbuffer) {
+        glXDestroyPbuffer(xDisplay, glxPbuffer);
+        glxPbuffer = 0;
     }
 
-    glXDestroyContext(x_display, gl_context);
+    glXDestroyContext(xDisplay, glContext);
 #endif
 }
 
@@ -302,15 +312,15 @@ void HeadlessView::notify_map_change(mbgl::MapChange /*change*/, mbgl::timestamp
 
 void HeadlessView::make_active() {
 #if MBGL_USE_CGL
-    CGLError error = CGLSetCurrentContext(gl_context);
-    if (error) {
-        throw std::runtime_error("Switching OpenGL context failed\n");
+    CGLError error = CGLSetCurrentContext(glContext);
+    if (error != kCGLNoError) {
+        throw std::runtime_error(std::string("Switching OpenGL context failed:") + CGLErrorString(error) + "\n");
     }
 #endif
 
 #if MBGL_USE_GLX
-    if (!glXMakeContextCurrent(x_display, glx_pbuffer, glx_pbuffer, gl_context)) {
-        throw std::runtime_error("Switching OpenGL context failed\n");
+    if (!glXMakeContextCurrent(xDisplay, glxPbuffer, glxPbuffer, glContext)) {
+        throw std::runtime_error("Switching OpenGL context failed.\n");
     }
 #endif
 }
@@ -318,14 +328,14 @@ void HeadlessView::make_active() {
 void HeadlessView::make_inactive() {
 #if MBGL_USE_CGL
     CGLError error = CGLSetCurrentContext(nullptr);
-    if (error) {
-        throw std::runtime_error("Removing OpenGL context failed\n");
+    if (error != kCGLNoError) {
+        throw std::runtime_error(std::string("Removing OpenGL context failed:") + CGLErrorString(error) + "\n");
     }
 #endif
 
 #if MBGL_USE_GLX
-    if (!glXMakeContextCurrent(x_display, 0, 0, nullptr)) {
-        throw std::runtime_error("Removing OpenGL context failed\n");
+    if (!glXMakeContextCurrent(xDisplay, 0, 0, nullptr)) {
+        throw std::runtime_error("Removing OpenGL context failed.\n");
     }
 #endif
 }
@@ -333,4 +343,3 @@ void HeadlessView::make_inactive() {
 void HeadlessView::swap() {}
 
 }
-