Fix Intel "Failed to map buffer for frame" during playback#274
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tedwaine merged 1 commit intoJun 18, 2026
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The Mac (__OPENGL_4_1__) path assigned the glMapBuffer result to mapped_address_, so the cache check at the top of map_buffer_for_upload (if (!resize(buffer_size) && mapped_address_) return mapped_address_;) short-circuited on subsequent calls. The non-Mac path returned the glMapNamedBuffer result directly without storing it, so mapped_address_ stayed null and the check never fired. Every prepare-for-upload re-ran glNamedBufferData + glMapNamedBuffer on the same PBO. NVIDIA accepts this re-orphan-and-map pattern. Intel doesn't: the remap returns NULL once the buffer has been used as a GL_PIXEL_UNPACK_BUFFER source, which logs 'Failed to map buffer for frame' during normal playback. Fix: assign the map result to mapped_address_ so the cache check fires. Clear it after glUnmapNamedBuffer in __bind, and after the buffer deletion in resize(), so we don't return a stale pointer. Signed-off-by: Ben de Luca <bdeluca@gmail.com>
tedwaine
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The Mac (
__OPENGL_4_1__) path ofGLBlindRGBA8bitTex::map_buffer_for_uploadstores theglMapBufferresult inmapped_address_, so the cache check at the top short-circuits subsequent calls. The non-Mac path returnedglMapNamedBufferdirectly without storing it, so the cache never fired and every prepare-for-upload re-ranglNamedBufferData+glMapNamedBufferon the same PBO.NVIDIA accepts the re-orphan-and-map; Intel returns NULL once the buffer has been used as a
GL_PIXEL_UNPACK_BUFFERsource, which spams "Failed to map buffer for frame" during normal playback. Store the map result, clear it afterglUnmapNamedBufferin__bind, and after buffer deletion inresize()so we don't return a stale pointer.Tested on Windows with both Intel and NVIDIA GPUs, and on Linux with NVIDIA. If it's really necessary to test the Linux/Intel combination I can do it, but it won't be until next week.