1 files changed, 74 insertions, 0 deletions
diff --git a/common/headless_display.cpp b/common/headless_display.cpp
new file mode 100644
index 0000000000..3aaf2020b9
--- /dev/null
+++ b/common/headless_display.cpp
@@ -0,0 +1,74 @@
+#include "headless_display.hpp"
+
+#include <cstring>
+#include <stdexcept>
+
+namespace mbgl {
+
+HeadlessDisplay::HeadlessDisplay() {
+#if MBGL_USE_CGL
+    // TODO: test if OpenGL 4.1 with GL_ARB_ES2_compatibility is supported
+    // If it is, use kCGLOGLPVersion_3_2_Core and enable that extension.
+    CGLPixelFormatAttribute attributes[] = {
+        kCGLPFAOpenGLProfile,
+        (CGLPixelFormatAttribute) kCGLOGLPVersion_Legacy,
+        kCGLPFAAccelerated,
+        (CGLPixelFormatAttribute) 0
+    };
+
+    GLint num;
+    CGLError error = CGLChoosePixelFormat(attributes, &pixelFormat, &num);
+    if (error) {
+        fprintf(stderr, "Error pixel format: %s\n", CGLErrorString(error));
+        return;
+    }
+#endif
+
+#if MBGL_USE_GLX
+    if (!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");
+    }
+
+    const char *extensions = (char *)glXQueryServerString(x_display, DefaultScreen(x_display), GLX_EXTENSIONS);
+    if (!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");
+    }
+    if (!strstr(extensions, "GLX_SGIX_pbuffer")) {
+        throw std::runtime_error("Cannot find glXCreateContextAttribsARB");
+    }
+
+    // We're creating a dummy pbuffer anyway that we're not using.
+    static int pixelFormat[] = {
+        GLX_DRAWABLE_TYPE, GLX_PBUFFER_BIT,
+        None
+    };
+
+    int configs = 0;
+    fb_configs = glXChooseFBConfig(x_display, DefaultScreen(x_display), pixelFormat, &configs);
+    if (configs <= 0) {
+        throw std::runtime_error("No Framebuffer configurations");
+    }
+#endif
+}
+
+HeadlessDisplay::~HeadlessDisplay() {
+#if MBGL_USE_CGL
+    CGLDestroyPixelFormat(pixelFormat);
+#endif
+
+#if MBGL_USE_GLX
+    XFree(fb_configs);
+    XCloseDisplay(x_display);
+#endif
+}
+
+}
+