lv_opengles_pbuffer.h

lv_opengles_pbuffer_get_gles_version

Get the OpenGL ES major version of the context backing a pbuffer display. ES3 is requested first, but drivers that cannot provide it fall back to ES2, where features needing ES3 shaders (e.g. glTF) are unavailable.

uint8_t lv_opengles_pbuffer_get_gles_version(lv_display_t *display)

Returns: uint8_t — 3 or 2, or 0 if display is not a pbuffer display

lv_opengles_pbuffer_get_handle

Get the pbuffer handle of a display, so it can be torn down after the display itself is gone. See lv_opengles_pbuffer_destroy.

lv_opengles_pbuffer_t * lv_opengles_pbuffer_get_handle(lv_display_t *display)

Returns: lv_opengles_pbuffer_t * — the handle, or NULL if display is not a pbuffer display

lv_opengles_pbuffer_create

Create a display that renders off-screen into an EGL pbuffer and reads the result back into its draw buffer, so no window system is needed.

The resolution and color format are fixed at creation; changing either on the returned display is not supported.

lv_display_t * lv_opengles_pbuffer_create(int32_t hor_res, int32_t ver_res)

Returns: lv_display_t * — the new display, or NULL on failure

lv_opengles_pbuffer_read_to_draw_buf

Read the pbuffer display's current framebuffer contents into a draw buffer. Called automatically when the display is flushed; use it directly only to take an extra copy. The draw buffer must match the display resolution.

lv_result_t lv_opengles_pbuffer_read_to_draw_buf(lv_display_t *display, lv_draw_buf_t *draw_buf)

Returns: lv_result_t — LV_RESULT_OK on success, LV_RESULT_INVALID on error

lv_opengles_pbuffer_destroy

Destroy a pbuffer context, releasing its GL objects and the EGL context.

This is deliberately not done when the display is deleted. Draw units may still run GL calls while they are being destroyed, and lv_deinit() deletes displays before draw units, so tearing the EGL context down from the display's delete event would pull the context out from under them. Fetch the handle with lv_opengles_pbuffer_get_handle() beforehand and call this afterwards.

void lv_opengles_pbuffer_destroy(lv_opengles_pbuffer_t *pbuffer)