Updating a Graphics Driver

This chapter describes how to update an existing graphics driver to the new QNX Graphics Framework.

In this chapter...

• Overview
• API changes

Overview

If you've written a driver using previous versions of the QNX Graphics DDK, you can update it to work with the current version using the instructions and tips in this chapter.

These are the general changes you'll need to make in your driver:

• The driver context is now split into two pieces, one to be shared across all clients, and one per client. The disp_adapter_t->shmem member points to the shared context.
• Memory is handled differently. You can no longer fall back on system RAM inside the graphics driver driver. You can't allocate video memory directly in draw functions. Instead, use disp_vm_alloc_surface_external().
• There's now two wait_idle() functions. The new wait_idle() in disp_draw_miscfuncs_t is called from io-display. The wait_idle() in disp_draw_corefuncs_t is called by external clients only.
• Make sure you supply disp_draw_miscfuncs_t.get_corefuncs_sw() and disp_draw_miscfuncs_t.get_contextfuncs_sw().
• Make sure that disp_draw_corefuncs_t.wait_idle() is filled in regardless of the pixel format.
• Video synchronization: the driver sets the adapter->vsync_counter member to point to an array, with one element per display. The driver must increase this value open receipt of an interrupt, at least once per call to wait_vsync().

API changes

These are the changes to the Graphics Framework API from the previous version. You'll need to update your driver to include the new functions. Deprecated functions and structures will still compile, but are not used by the Framework.

disp_adapter_t

Deprecated:

• vid_ctx
• disp_modefuncs
• disp_memfuncs

disp_draw_context_t

Several changes, including:

Deprecated:

• alpha_map_width
• alpha_map_height

Changed: alpha_map is a pointer to a disp_surface_t, not unsigned char

New:

    unsigned        plane_mask;
    int             clip_left;
    int             clip_top;
    int             clip_right;
    int             clip_bottom;
    unsigned char   *palette_lut;
    disp_color_t    *dest_palette;
    int             dest_palette_size;
    disp_fx_t       xform_matrix[4];
    int             xlate_x;
    int             xlate_y;
    unsigned        line_flags;
    int             line_join;
    uint32_t        line_pat;
    int             line_repeat;
    int             line_initial_offset;
    int             cap_style;
    int             poly_fill;
    

disp_draw_contextfuncs_t

New members:

    void (*scaled_blit) (…);
    void (*update_planemask) (…);
    void (*draw_line) (…);
    int (*fill_poly) (…);
    int (*draw_polyline) (…);
    void (*update_line) (…);
    void (*blend_pixels) (…);
    

disp_draw_miscfuncs_t

These new functions are defined:

• end_of_draw
• attach_external
• detach_external
• recover) (…
• wait_idle) (…

disp_layer_query_t

Has a new member, order_mask.

disp_memfuncs_t

New members:

    int (*query_apertures) (…);
    int (*query_surface) (…);
    int (*get_alloc_info) (…);
    int (*get_alloc_layer_info) (…);
    

disp_modefuncs_t

Deprecated:

• set_scroll_position
• layer_select_format

Changed:

• layer_update_begin
• layer_update_end

New:

    int (*layer_set_order)  (…);
    int (*set_hw_cursor)  (…);
    void (*enable_hw_cursor)  (…);
    void (*disable_hw_cursor)  (…);
    void (*set_hw_cursor_pos)  (…);
    int (*i2c_read)  (…);
    int (*i2c_write)  (…);
    int (*i2c_writeread)  (…);
    

disp_vcapfuncs_t

Deprecated:

• get_channel_caps
• get_channel_status
• set_channel_props
• close_channel

New:

    int (*set_props)) (…);
    int (*set_adjustments) (…);
    int (*bind_layer) (…);
    int (*set_enabled) (…);
    void (*wait_vsync) (…);
    

These video capture structures are deprecated:

• disp_vcap_channel_caps_t
• disp_vcap_channel_props_t (use disp_vcap_props_t instead)
• disp_vcap_channel_status_t

These video scaler structures are deprecated:

• disp_vid_channel_caps_t
• disp_vid_channel_props_t
• dis_vidfuncs_t