[AD] [WIN] windowed driver patch

["Eric Botcazou" <ebotcazou@xxxxxxxxxx>]

Hi,
I've tried to improve the dirty rectangles mechanism used in the refreshing
process by the DirectDraw windowed driver: the drawing calls are now, as
much as possible, grouped and there is no more need for entire window
updates.
The best results are achieved with non hardware-accelerated block-blitting
functions:

Allegro 3.9.34 (CVS), Mingw32 profile results (ATI Xpert@xxxxxxxxxx 98 AGP)

Graphics driver: DirectDraw window
Description: DirectDraw window

Screen size: 640x480
Virtual screen size: 640x480
Color depth: 15 bpp

Hardware acceleration:

    solid scanline fills
    solid area fills
    vram->vram blits
    masked vram->vram blits
    system->vram blits
    masked system->vram blits

DRAW_MODE_SOLID results:        3.9.34       3.9.34++

    putpixel()      -            5317         5426
    hline()         -            7002         6946
    vline()         -            6656         6830
    line()          -            305          1882
    rectfill()      -            5147         5148
    circle()        -            295          1373
    circlefill()    -            89           123
    ellipse()       -            291          1286
    ellipsefill()   -            84           118
    arc()           -            298          1892
    triangle()      -            85           114


Other functions:

    textout()                    - 300        3103
    vram->vram blit()            - 5426       5451
    aligned vram->vram blit()    - 5533       5525
    blit() from memory           - 261        1791
    aligned blit() from memory   - 265        1937
    vram->vram masked_blit()     - 5356       5334
    masked_blit() from memory    - 261        1859
    draw_sprite()                - 295        2242
    draw_rle_sprite()            - 294        2313
    draw_compiled_sprite()       - 297        2409
    draw_trans_sprite()          - 266        1235
    draw_trans_rle_sprite()      - 263        1199
    draw_lit_sprite()            - 286        1730
    draw_lit_rle_sprite()        - 284        1738


However, in real world games, the speed improvement may be less obvious,
heavily depending on the animation method:
  Allegro demo game, 640x480 15bpp window (color conversion - MMX disabled)

                       3.9.34          3.9.34++
double buffering         12              33
page flipping            50              50
triple buffering         34              48
dirty rectangles         60              60

BtW, I've also added a new description string to the driver (a la X-Window).

--
Eric Botcazou (ebotcazou@xxxxxxxxxx)
Web Site: http://www.multimania.com/ebotcazou

Attachment: wd_patch2.zip
Description: Zip compressed data