lower our expectations towards the pbuffer and use framebuffers instead

common/headless_display.cpp

@@ -45,15 +45,9 @@ HeadlessDisplay::HeadlessDisplay() {
         throw std::runtime_error("Cannot find glXCreateContextAttribsARB");
     }
 
-
+    // We're creating a dummy pbuffer anyway that we're not using.
     static int pixelFormat[] = {
-        GLX_DOUBLEBUFFER, False,
-        GLX_RED_SIZE, 8,
-        GLX_GREEN_SIZE, 8,
-        GLX_BLUE_SIZE, 8,
-        GLX_ALPHA_SIZE, 8,
-        GLX_DEPTH_SIZE, 24,
-        GLX_STENCIL_SIZE, 8,
+        GLX_DRAWABLE_TYPE, GLX_PBUFFER_BIT,
         None
     };
 
@@ -62,8 +56,6 @@ HeadlessDisplay::HeadlessDisplay() {
     if (configs <= 0) {
         throw std::runtime_error("No Framebuffer configurations");
     }
-
-    XSync(x_display, False);
 #endif
 }
 

common/headless_view.cpp

@@ -47,18 +47,25 @@ void HeadlessView::createContext() {
     fb_configs = display_->fb_configs;
 
 
-    int attributes[] = {
+    int context_attributes[] = {
         GLX_CONTEXT_MAJOR_VERSION_ARB, 2,
         GLX_CONTEXT_MINOR_VERSION_ARB, 1,
         GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_DEBUG_BIT_ARB,
         GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB,
         None
     };
-    gl_context = glXCreateContextAttribsARB(x_display, fb_configs[0], 0, True, attributes);
+    gl_context = glXCreateContextAttribsARB(x_display, fb_configs[0], 0, True, context_attributes);
     if (gl_context == nullptr) {
         throw std::runtime_error("Error creating GL context object");
     }
 
+    int pbuffer_attributes[] = {
+        GLX_PBUFFER_WIDTH, 32,
+        GLX_PBUFFER_HEIGHT, 32,
+        None
+    };
+    glx_pbuffer = glXCreatePbuffer(x_display, fb_configs[0], pbuffer_attributes);
+
 #endif
 }
 
@@ -72,7 +79,6 @@ void HeadlessView::resize(uint16_t width, uint16_t height, float pixelRatio) {
     const unsigned int w = width_ * pixelRatio_;
     const unsigned int h = height_ * pixelRatio_;
 
-#if MBGL_USE_CGL
     make_active();
 
     // Create depth/stencil buffer
@@ -110,16 +116,6 @@ void HeadlessView::resize(uint16_t width, uint16_t height, float pixelRatio) {
     }
 
     make_inactive();
-#endif
-
-#if MBGL_USE_GLX
-    int attributes[] = {
-        GLX_PBUFFER_WIDTH, static_cast<int>(w),
-        GLX_PBUFFER_HEIGHT, static_cast<int>(h),
-        None
-    };
-    glx_pbuffer = glXCreatePbuffer(x_display, fb_configs[0], attributes);
-#endif
 }
 
 const std::unique_ptr<uint32_t[]> HeadlessView::readPixels() {
@@ -136,7 +132,6 @@ const std::unique_ptr<uint32_t[]> HeadlessView::readPixels() {
 }
 
 void HeadlessView::clear_buffers() {
-#if MBGL_USE_CGL
     make_active();
 
     glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
@@ -157,16 +152,6 @@ void HeadlessView::clear_buffers() {
     }
 
     make_inactive();
-#endif
-
-#if MBGL_USE_GLX
-    make_inactive();
-
-    if (glx_pbuffer) {
-        glXDestroyPbuffer(x_display, glx_pbuffer);
-        glx_pbuffer = 0;
-    }
-#endif
 }
 
 HeadlessView::~HeadlessView() {
@@ -177,6 +162,11 @@ HeadlessView::~HeadlessView() {
 #endif
 
 #if MBGL_USE_GLX
+    if (glx_pbuffer) {
+        glXDestroyPbuffer(x_display, glx_pbuffer);
+        glx_pbuffer = 0;
+    }
+
     glXDestroyContext(x_display, gl_context);
 #endif
 }

common/headless_view.hpp

@@ -4,6 +4,7 @@
 #ifdef __APPLE__
 #define MBGL_USE_CGL 1
 #else
+#define GL_GLEXT_PROTOTYPES
 #include <GL/glx.h>
 #define MBGL_USE_GLX 1
 #endif
@@ -46,9 +47,6 @@ private:
 
 #if MBGL_USE_CGL
     CGLContextObj gl_context;
-    GLuint fbo = 0;
-    GLuint fbo_depth_stencil = 0;
-    GLuint fbo_color = 0;
 #endif
 
 #if MBGL_USE_GLX
@@ -57,6 +55,10 @@ private:
     GLXContext gl_context = nullptr;
     GLXPbuffer glx_pbuffer = 0;
 #endif
+
+    GLuint fbo = 0;
+    GLuint fbo_depth_stencil = 0;
+    GLuint fbo_color = 0;
 };
 
 }