{"id":4431,"date":"2021-06-05T22:59:44","date_gmt":"2021-06-05T20:59:44","guid":{"rendered":"https:\/\/entropie.org\/3615\/?p=4431"},"modified":"2021-06-06T23:48:16","modified_gmt":"2021-06-06T21:48:16","slug":"mesures-de-vitesse-sur-putpixel-en-mode-13h","status":"publish","type":"post","link":"https:\/\/entropie.org\/3615\/index.php\/2021\/06\/05\/mesures-de-vitesse-sur-putpixel-en-mode-13h\/","title":{"rendered":"Mesures de vitesse sur PutPixel en mode 13h"},"content":{"rendered":"<p>Test de 3 fa\u00e7ons diff\u00e9rentes d&rsquo;afficher un pixel (avec Turbo Pascal 7.0) :<\/p>\n<pre>\r\n(***************************************************************)\r\n\r\nprocedure PutPixel1(x,y: word; color: byte);\r\nbegin\r\n  Mem[VGA_SEGMENT: y*320+x]:=color;\r\nend; { PutPixel1 }\r\n\r\n(***************************************************************)\r\n\r\nprocedure PutPixel2(x,y: word; color: byte); assembler;\r\nasm\r\n  mov  ax,VGA_SEGMENT  { es <-- $A000 }\r\n  mov  es,ax\r\n  mov  ax,VGA_WIDTH    { ax <-- 320 }\r\n  mul  y               { ax <-- y*320 }\r\n  add  ax,x            { ax <-- y*320+x }\r\n  mov  bx,ax           { bx <-- y*320+x }\r\n  mov  al,color\r\n  mov  es:[bx],al\r\nend; { PutPixel2 }\r\n\r\n(***************************************************************)\r\n\r\nprocedure PutPixel3(x,y: word; color: byte); assembler;\r\nasm\r\n  mov  ax,VGA_SEGMENT  { es <-- $A000 }\r\n  mov  es,ax\r\n  mov  ax, y   { ax <-- y }\r\n  mov  di, ax  { di <-- y }\r\n  shl  ax, 8   { ax <-- y*256 }\r\n  shl  di, 6   { di <-- y*64 }\r\n  add  di, ax  { di <-- y*320 }\r\n  add  di, x   { di <-- y*320+x }\r\n  mov  al, color\r\n  mov  [es:di],al\r\nend; { PutPixel3 }\r\n\r\n(***************************************************************)\r\n<\/pre>\n<p>Sous DOSBox, la proc\u00e9dure la plus rapide semble \u00eatre la premi\u00e8re (test r\u00e9alis\u00e9 plusieurs fois) :<\/p>\n<p><a href=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel.png\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel.png\" alt=\"\" width=\"646\" height=\"432\" class=\"alignnone size-full wp-image-4432\" srcset=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel.png 646w, https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel-300x201.png 300w\" sizes=\"(max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 984px) 61vw, (max-width: 1362px) 45vw, 600px\" \/><\/a><\/p>\n<p>Extrait du programme de test :<\/p>\n<pre>\r\nfor c:=0 to 15 do\r\nbegin\r\n  for y:=0 to 199 do\r\n  begin\r\n    for x:=0 to 319 do\r\n    begin\r\n      PutPixel1(x,y,c);\r\n    end;\r\n  end;\r\nend;\r\n<\/pre>\n<p>En approfondissant, et pour une raison que je ne m'explique pas, on se rend compte que la position des PutPixels dans le programme a une influence : le premier est avantag\u00e9. J'ai donc chang\u00e9 la m\u00e9thodologie et arrive \u00e0 ceci :<\/p>\n<p><a href=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel1.png\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel1.png\" alt=\"\" width=\"646\" height=\"432\" class=\"alignnone size-full wp-image-4446\" srcset=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel1.png 646w, https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel1-300x201.png 300w\" sizes=\"(max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 984px) 61vw, (max-width: 1362px) 45vw, 600px\" \/><\/a><br \/>\n<a href=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel2.png\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel2.png\" alt=\"\" width=\"646\" height=\"432\" class=\"alignnone size-large wp-image-4447\" srcset=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel2.png 646w, https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel2-300x201.png 300w\" sizes=\"(max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 984px) 61vw, (max-width: 1362px) 45vw, 600px\" \/><\/a><br \/>\n<a href=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel3.png\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel3.png\" alt=\"\" width=\"646\" height=\"432\" class=\"alignnone size-large wp-image-4448\" srcset=\"https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel3.png 646w, https:\/\/entropie.org\/3615\/wp-content\/uploads\/2021\/06\/putpixel3-300x201.png 300w\" sizes=\"(max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 984px) 61vw, (max-width: 1362px) 45vw, 600px\" \/><\/a><\/p>\n<p>PutPixel2 semble \u00eatre la proc\u00e9dure plus rapide. Je suis autour de 25,4 ms par \u00e9cran, soit 39,4 FPS.<\/p>\n<p>Si vous pensez avoir mieux au niveau du code, je suis preneur...<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Test de 3 fa\u00e7ons diff\u00e9rentes d&rsquo;afficher un pixel (avec Turbo Pascal 7.0) : (***************************************************************) procedure PutPixel1(x,y: word; color: byte); begin Mem[VGA_SEGMENT: y*320+x]:=color; end; { PutPixel1 } (***************************************************************) procedure PutPixel2(x,y: word; color: byte); assembler; asm mov ax,VGA_SEGMENT { es<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[37,35,36],"tags":[],"class_list":["post-4431","post","type-post","status-publish","format-standard","hentry","category-assembleur","category-dos","category-pascal"],"_links":{"self":[{"href":"https:\/\/entropie.org\/3615\/index.php\/wp-json\/wp\/v2\/posts\/4431"}],"collection":[{"href":"https:\/\/entropie.org\/3615\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/entropie.org\/3615\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/entropie.org\/3615\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/entropie.org\/3615\/index.php\/wp-json\/wp\/v2\/comments?post=4431"}],"version-history":[{"count":23,"href":"https:\/\/entropie.org\/3615\/index.php\/wp-json\/wp\/v2\/posts\/4431\/revisions"}],"predecessor-version":[{"id":4458,"href":"https:\/\/entropie.org\/3615\/index.php\/wp-json\/wp\/v2\/posts\/4431\/revisions\/4458"}],"wp:attachment":[{"href":"https:\/\/entropie.org\/3615\/index.php\/wp-json\/wp\/v2\/media?parent=4431"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/entropie.org\/3615\/index.php\/wp-json\/wp\/v2\/categories?post=4431"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/entropie.org\/3615\/index.php\/wp-json\/wp\/v2\/tags?post=4431"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}