Fix T92090: Eevee crash with Intel HD 4000 and macOS 10.15.7

A recent security update to macOS 10.15.7 causes crashes when using Eevee and
various other 3D viewport features. It appears that glGenerateMipmap is
broken, causing a crash whenever its commands are flushed/submitted to the GPU.

Ideally this would be fixed in a driver update, however it's unlikely this will
happen. Earlier macOS versions have been receiving security updates for 2 years,
and that window has just passed for 10.15. Further, computers with these GPUs
can't upgrade to a newer macOS version.

As a workaround, disable mipmaps on these GPUs, by setting the mipmap max level
to 0 and not calling glGenerateMipmaps. Effects like depth of field also use
mipmaps, but fill in the mip levels by other means. In those cases we keep the
mipmap level.

Differential Revision: https://developer.blender.org/D13295

source/blender/gpu/opengl/gl_backend.cc

@@ -412,6 +412,12 @@ static void detect_workarounds()
   if (GLContext::debug_layer_support == false) {
     GLContext::debug_layer_workaround = true;
   }
+
+  /* Broken glGenerateMipmap on macOS 10.15.7 security update. */
+  if (GPU_type_matches(GPU_DEVICE_INTEL, GPU_OS_MAC, GPU_DRIVER_ANY) &&
+      strstr(renderer, "HD Graphics 4000")) {
+    GLContext::generate_mipmap_workaround = true;
+  }
 }  // namespace blender::gpu
 
 /** Internal capabilities. */
@@ -436,6 +442,7 @@ bool GLContext::vertex_attrib_binding_support = false;
 /** Workarounds. */
 bool GLContext::debug_layer_workaround = false;
 bool GLContext::unused_fb_slot_workaround = false;
+bool GLContext::generate_mipmap_workaround = false;
 float GLContext::derivative_signs[2] = {1.0f, 1.0f};
 
 void GLBackend::capabilities_init()

source/blender/gpu/opengl/gl_context.hh

@@ -77,6 +77,7 @@ class GLContext : public Context {
   /** Workarounds. */
   static bool debug_layer_workaround;
   static bool unused_fb_slot_workaround;
+  static bool generate_mipmap_workaround;
   static float derivative_signs[2];
 
   /** VBO for missing vertex attrib binding. Avoid undefined behavior on some implementation. */

source/blender/gpu/opengl/gl_texture.cc

@@ -225,6 +225,8 @@ void GLTexture::update_sub_direct_state_access(
         break;
     }
   }
+
+  has_pixels_ = true;
 }
 
 void GLTexture::update_sub(
@@ -288,6 +290,8 @@ void GLTexture::update_sub(
         break;
     }
   }
+
+  has_pixels_ = true;
 }
 
 /**
@@ -307,6 +311,16 @@ void GLTexture::generate_mipmap()
     return;
   }
 
+  if (GLContext::generate_mipmap_workaround) {
+    /* Broken glGenerateMipmap, don't call it and render without mipmaps.
+     * If no top level pixels have been filled in, the levels will get filled by
+     * other means and there is no need to disable mipmapping. */
+    if (has_pixels_) {
+      this->mip_range_set(0, 0);
+    }
+    return;
+  }
+
   /* Down-sample from mip 0 using implementation. */
   if (GLContext::direct_state_access_support) {
     glGenerateTextureMipmap(tex_id_);
@@ -337,6 +351,8 @@ void GLTexture::clear(eGPUDataFormat data_format, const void *data)
 
     GPU_framebuffer_bind(prev_fb);
   }
+
+  has_pixels_ = true;
 }
 
 void GLTexture::copy_to(Texture *dst_)
@@ -363,6 +379,8 @@ void GLTexture::copy_to(Texture *dst_)
     GPU_framebuffer_blit(
         src->framebuffer_get(), 0, dst->framebuffer_get(), 0, to_framebuffer_bits(format_));
   }
+
+  has_pixels_ = true;
 }
 
 void *GLTexture::read(int mip, eGPUDataFormat type)
@@ -452,6 +470,7 @@ struct GPUFrameBuffer *GLTexture::framebuffer_get()
   GPUTexture *gputex = reinterpret_cast<GPUTexture *>(static_cast<Texture *>(this));
   framebuffer_ = GPU_framebuffer_create(name_);
   GPU_framebuffer_texture_attach(framebuffer_, gputex, 0, 0);
+  has_pixels_ = true;
   return framebuffer_;
 }
 

source/blender/gpu/opengl/gl_texture.hh

@@ -53,6 +53,8 @@ class GLTexture : public Texture {
   /** True if this texture is bound to at least one texture unit. */
   /* TODO(fclem): How do we ensure thread safety here? */
   bool is_bound_ = false;
+  /** True if pixels in the texture have been initialized. */
+  bool has_pixels_ = false;
 
  public:
   GLTexture(const char *name);