1 files changed, 113 insertions, 0 deletions
diff --git a/platform/darwin/src/headless_view_cgl.cpp b/platform/darwin/src/headless_view_cgl.cpp
new file mode 100644
index 0000000000..a4f809a250
--- /dev/null
+++ b/platform/darwin/src/headless_view_cgl.cpp
@@ -0,0 +1,113 @@
+#include <mbgl/platform/default/headless_view.hpp>
+#include <mbgl/platform/default/headless_display.hpp>
+
+#include <CoreFoundation/CoreFoundation.h>
+
+namespace mbgl {
+
+gl::glProc HeadlessView::initializeExtension(const char* name) {
+    static CFBundleRef framework = CFBundleGetBundleWithIdentifier(CFSTR("com.apple.opengl"));
+    if (!framework) {
+        throw std::runtime_error("Failed to load OpenGL framework.");
+    }
+
+    CFStringRef str = CFStringCreateWithCString(kCFAllocatorDefault, name, kCFStringEncodingASCII);
+    void* symbol = CFBundleGetFunctionPointerForName(framework, str);
+    CFRelease(str);
+
+    return reinterpret_cast<gl::glProc>(symbol);
+}
+
+void HeadlessView::createContext() {
+    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(glContext, kCGLCEMPEngine);
+    if (error != kCGLNoError) {
+        throw std::runtime_error(std::string("Error enabling OpenGL multithreading:") + CGLErrorString(error) + "\n");
+    }
+}
+
+void HeadlessView::destroyContext() {
+    CGLDestroyContext(glContext);
+}
+
+void HeadlessView::resizeFramebuffer() {
+    const unsigned int w = dimensions[0] * pixelRatio;
+    const unsigned int h = dimensions[1] * pixelRatio;
+
+    // Create depth/stencil buffer
+    MBGL_CHECK_ERROR(glGenRenderbuffersEXT(1, &fboDepthStencil));
+    MBGL_CHECK_ERROR(glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fboDepthStencil));
+    MBGL_CHECK_ERROR(glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH24_STENCIL8_EXT, w, h));
+    MBGL_CHECK_ERROR(glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, 0));
+
+    MBGL_CHECK_ERROR(glGenRenderbuffersEXT(1, &fboColor));
+    MBGL_CHECK_ERROR(glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fboColor));
+    MBGL_CHECK_ERROR(glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGBA8, w, h));
+    MBGL_CHECK_ERROR(glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, 0));
+
+    MBGL_CHECK_ERROR(glGenFramebuffersEXT(1, &fbo));
+    MBGL_CHECK_ERROR(glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo));
+
+    MBGL_CHECK_ERROR(glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_RENDERBUFFER_EXT, fboColor));
+    MBGL_CHECK_ERROR(glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER_EXT, fboDepthStencil));
+
+    GLenum status = MBGL_CHECK_ERROR(glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT));
+
+    if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+        std::string error("Couldn't create framebuffer: ");
+        switch (status) {
+            case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT: (error += "incomplete attachment"); break;
+            case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT: error += "incomplete missing attachment"; break;
+            case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT: error += "incomplete dimensions"; break;
+            case GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT: error += "incomplete formats"; break;
+            case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT: error += "incomplete draw buffer"; break;
+            case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT: error += "incomplete read buffer"; break;
+            case GL_FRAMEBUFFER_UNSUPPORTED: error += "unsupported"; break;
+            default: error += "other"; break;
+        }
+        throw std::runtime_error(error);
+    }
+
+    MBGL_CHECK_ERROR(glViewport(0, 0, w, h));
+}
+
+void HeadlessView::clearBuffers() {
+    assert(active);
+
+    MBGL_CHECK_ERROR(glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0));
+
+    if (fbo) {
+        MBGL_CHECK_ERROR(glDeleteFramebuffersEXT(1, &fbo));
+        fbo = 0;
+    }
+
+    if (fboColor) {
+        MBGL_CHECK_ERROR(glDeleteRenderbuffersEXT(1, &fboColor));
+        fboColor = 0;
+    }
+
+    if (fboDepthStencil) {
+        MBGL_CHECK_ERROR(glDeleteRenderbuffersEXT(1, &fboDepthStencil));
+        fboDepthStencil = 0;
+    }
+}
+
+void HeadlessView::activateContext() {
+    CGLError error = CGLSetCurrentContext(glContext);
+    if (error != kCGLNoError) {
+        throw std::runtime_error(std::string("Switching OpenGL context failed:") + CGLErrorString(error) + "\n");
+    }
+}
+
+void HeadlessView::deactivateContext() {
+    CGLError error = CGLSetCurrentContext(nullptr);
+    if (error != kCGLNoError) {
+        throw std::runtime_error(std::string("Removing OpenGL context failed:") + CGLErrorString(error) + "\n");
+    }
+}
+
+} // namespace mbgl