Nesta nota descreverei o processo de leitura do joystick, mudan\u00e7a de posi\u00e7\u00e3o do sprite, giro horizontal, emulador Sega Genesis e potencialmente o pr\u00f3prio console.<\/p>\n
A leitura de cliques e o processamento de \u201ceventos\u201d de um joystick shogi ocorre de acordo com o seguinte esquema:<\/p>\n
Para mover o sprite do esqueleto, precisamos armazenar vari\u00e1veis \u200b\u200bda posi\u00e7\u00e3o atual.<\/p>\n
As vari\u00e1veis \u200b\u200bl\u00f3gicas do jogo s\u00e3o armazenadas na RAM; at\u00e9 agora as pessoas n\u00e3o encontraram nada melhor. Vamos declarar endere\u00e7os de vari\u00e1veis \u200b\u200be alterar o c\u00f3digo de renderiza\u00e7\u00e3o:<\/p>\n
skeletonYpos = $FF0002 \nframeCounter = $FF0004 \nskeletonHorizontalFlip = $FF0006\n\n move.w #$0100,skeletonXpos \n move.w #$0100,skeletonYpos \n move.w #$0001,skeletonHorizontalFlip \n\nFillSpriteTable: \n move.l #$70000003,vdp_control_port \n move.w skeletonYpos,vdp_data_port \n move.w #$0F00,vdp_data_port \n move.w skeletonHorizontalFlip,vdp_data_port \n move.w skeletonXpos,vdp_data_port \n<\/code><\/pre>\n<\/div>\nComo voc\u00ea pode ver, o endere\u00e7o dispon\u00edvel para trabalho come\u00e7a em 0xFF0000 e termina em 0xFFFFFF, no total temos 64 KB de mem\u00f3ria dispon\u00edveis. As posi\u00e7\u00f5es do esqueleto s\u00e3o declaradas em esqueletoXpos, esqueletoYpos, rota\u00e7\u00e3o horizontal em esqueletoHorizontalFlip.<\/p>\n
Joypad<\/h3>\n
Por analogia com o VDP, o trabalho com joypads ocorre atrav\u00e9s de duas portas separadamente – porta de controle e porta de dados, para a primeira 0xA10009 e 0xA10003 co-no. H\u00e1 um recurso interessante ao trabalhar com um joypad: Primeiro voc\u00ea precisa solicitar uma combina\u00e7\u00e3o de bot\u00f5es para polling e, em seguida, ap\u00f3s aguardar uma atualiza\u00e7\u00e3o no barramento, ler os pressionamentos necess\u00e1rios. Para os bot\u00f5es C\/B e D-pad \u00e9 0x40, exemplo abaixo:<\/p>\n
\n move.b #$40,joypad_one_control_port; C\/B\/Dpad \n nop ; bus sync \n nop ; bus sync \n move.b joypad_one_data_port,d2 \n rts \n<\/code><\/pre>\n<\/div>\nNo registro d2 permanecer\u00e1 o estado dos bot\u00f5es pressionados ou n\u00e3o pressionados, em geral permanecer\u00e1 o que foi solicitado atrav\u00e9s da porta data. Depois disso, v\u00e1 at\u00e9 o visualizador de registros Motorola 68000 do seu emulador favorito, veja a que \u00e9 igual o registro d2, dependendo das teclas digitadas. De forma inteligente, voc\u00ea pode descobrir no manual, mas n\u00e3o acreditamos apenas na palavra deles. Processamento adicional de bot\u00f5es pressionados no registro d2<\/p>\n
\n cmp #$FFFFFF7B,d2; handle left \n beq MoveLeft \n cmp #$FFFFFF77,d2; handle right \n beq MoveRight \n cmp #$FFFFFF7E,d2; handle up \n beq MoveUp \n cmp #$FFFFFF7D,d2; handle down \n beq MoveDown \n rts<\/code><\/pre>\n\u041f\u0440\u043e\u0432\u0435\u0440\u044f\u0442\u044c \u043d\u0443\u0436\u043d\u043e \u043a\u043e\u043d\u0435\u0447\u043d\u043e \u043e\u0442\u0434\u0435\u043b\u044c\u043d\u044b\u0435 \u0431\u0438\u0442\u044b, \u0430 \u043d\u0435 \u0446\u0435\u043b\u044b\u043c\u0438 \u0441\u043b\u043e\u0432\u0430\u043c\u0438, \u043d\u043e \u043f\u043e\u043a\u0430 \u0438 \u0442\u0430\u043a \u0441\u043e\u0439\u0434\u0435\u0442. \u0422\u0435\u043f\u0435\u0440\u044c \u043e\u0441\u0442\u0430\u043b\u043e\u0441\u044c \u0441\u0430\u043c\u043e\u0435 \u043f\u0440\u043e\u0441\u0442\u043e\u0435 – \u043d\u0430\u043f\u0438\u0441\u0430\u0442\u044c \u043e\u0431\u0440\u0430\u0431\u043e\u0442\u0447\u0438\u043a\u0438 \u0432\u0441\u0435\u0445 \u0441\u043e\u0431\u044b\u0442\u0438\u0439 \u043f\u0435\u0440\u0435\u043c\u0435\u0449\u0435\u043d\u0438\u044f \u043f\u043e 4-\u043c \u043d\u0430\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u044f\u043c. \u0414\u043b\u044f \u044d\u0442\u043e\u0433\u043e \u043c\u0435\u043d\u044f\u0435\u043c \u043f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u044b\u0435 \u0432 RAM, \u0438 \u0437\u0430\u043f\u0443\u0441\u043a\u0430\u0435\u043c \u043f\u0440\u043e\u0446\u0435\u0434\u0443\u0440\u0443 \u043f\u0435\u0440\u0435\u0440\u0438\u0441\u043e\u0432\u043a\u0438.<\/p>\n
\u041f\u0440\u0438\u043c\u0435\u0440 \u0434\u043b\u044f \u043f\u0435\u0440\u0435\u043c\u0435\u0449\u0435\u043d\u0438\u044f \u0432\u043b\u0435\u0432\u043e + \u0438\u0437\u043c\u0435\u043d\u0435\u043d\u0438\u0435 \u0433\u043e\u0440\u0438\u0437\u043e\u043d\u0442\u0430\u043b\u044c\u043d\u043e\u0433\u043e \u0444\u043b\u0438\u043f\u0430:<\/p>\n
\n move.w skeletonXpos,d0 \n sub.w #1,d0 \n move.w d0,skeletonXpos \n move.w #$0801,skeletonHorizontalFlip \n jmp FillSpriteTable<\/code><\/pre>\n\u041f\u043e\u0441\u043b\u0435 \u0434\u043e\u0431\u0430\u0432\u043b\u0435\u043d\u0438\u044f \u0432\u0441\u0435\u0445 \u043e\u0431\u0440\u0430\u0431\u043e\u0442\u0447\u0438\u043a\u043e\u0432 \u0438 \u0441\u0431\u043e\u0440\u043a\u0438, \u0432\u044b \u0443\u0432\u0438\u0434\u0438\u0442\u0435 \u043a\u0430\u043a \u0441\u043a\u0435\u043b\u0435\u0442 \u043f\u0435\u0440\u0435\u043c\u0435\u0449\u0430\u0435\u0442\u0441\u044f \u0438 \u043f\u043e\u0432\u043e\u0440\u0430\u0447\u0438\u0432\u0430\u0435\u0442\u0441\u044f \u043f\u043e \u044d\u043a\u0440\u0430\u043d\u0443, \u043d\u043e \u0441\u043b\u0438\u0448\u043a\u043e\u043c \u0431\u044b\u0441\u0442\u0440\u043e, \u0431\u044b\u0441\u0442\u0440\u0435\u0435 \u0441\u0430\u043c\u043e\u0433\u043e \u0435\u0436\u0430 \u0421\u043e\u043d\u0438\u043a\u0430.<\/p>\n
\u041d\u0435 \u0442\u0430\u043a \u0431\u044b\u0441\u0442\u0440\u043e!<\/h3>\n
\u0427\u0442\u043e\u0431\u044b \u0437\u0430\u043c\u0435\u0434\u043b\u0438\u0442\u044c \u0441\u043a\u043e\u0440\u043e\u0441\u0442\u044c \u0438\u0433\u0440\u043e\u0432\u043e\u0433\u043e \u0446\u0438\u043a\u043b\u0430, \u0441\u0443\u0449\u0435\u0441\u0442\u0432\u0443\u044e\u0442 \u043d\u0435\u0441\u043a\u043e\u043b\u044c\u043a\u043e \u0442\u0435\u0445\u043d\u0438\u043a, \u044f \u0432\u044b\u0431\u0440\u0430\u043b \u0441\u0430\u043c\u0443\u044e \u043f\u0440\u043e\u0441\u0442\u0443\u044e \u0438 \u043d\u0435 \u0437\u0430\u0442\u0440\u0430\u0433\u0438\u0432\u0430\u044e\u0449\u0443\u044e \u0440\u0430\u0431\u043e\u0442\u0443 \u0441 \u0432\u043d\u0435\u0448\u043d\u0438\u043c\u0438 \u043f\u043e\u0440\u0442\u0430\u043c\u0438 – \u043f\u043e\u0434\u0441\u0447\u0435\u0442 \u0446\u0438\u0444\u0440\u044b \u0447\u0435\u0440\u0435\u0437 \u0440\u0435\u0433\u0438\u0441\u0442\u0440 \u043f\u043e\u043a\u0430 \u043e\u043d\u0430 \u043d\u0435 \u0441\u0442\u0430\u043d\u0435\u0442 \u0440\u0430\u0432\u043d\u0430 \u043d\u0443\u043b\u044e.<\/p>\n
\u041f\u0440\u0438\u043c\u0435\u0440 \u0437\u0430\u043c\u0435\u0434\u043b\u044f\u044e\u0449\u0435\u0433\u043e \u0446\u0438\u043a\u043b\u0430 \u0438 \u0438\u0433\u0440\u043e\u0432\u043e\u0433\u043e \u0446\u0438\u043a\u043b\u0430:<\/p>\n
\n move.w #512,frameCounter \nWaitFrame: \n move.w frameCounter,d0 \n sub.w #1,d0 \n move.w d0,frameCounter \n dbra d0,WaitFrame \nGameLoop: \n jsr ReadJoypad \n jsr HandleJoypad \n jmp GameLoop \n<\/code><\/pre>\n<\/div>\nDepois disso, o esqueleto fica mais lento, o que era necess\u00e1rio. Como eu sei, a op\u00e7\u00e3o mais comum para \u201cdesacelerar\u201d \u00e9 contar o sinalizador de sincroniza\u00e7\u00e3o vertical, voc\u00ea pode contar quantas vezes a tela foi desenhada, ficando assim vinculada a um fps espec\u00edfico.<\/p>\n
Links<\/h3>\n
https:\/\/gitlab .com\/demensdeum\/segagenesisamples\/-\/blob\/main\/8Joypad\/vasm\/main.asm <\/a><\/p>\nFontes<\/h3>\n
https:\/\/www.chibiakumas.com\/68000\/platform2.php <\/a>
https:\/\/huguesjohnson.com\/programming\/genesis\/tiles-sprites\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Nesta nota descreverei o processo de leitura do joystick, mudan\u00e7a de posi\u00e7\u00e3o do sprite, giro horizontal, emulador Sega Genesis e potencialmente o pr\u00f3prio console. A leitura de cliques e o processamento de \u201ceventos\u201d de um joystick shogi ocorre de acordo com o seguinte esquema: Solicita\u00e7\u00e3o de uma combina\u00e7\u00e3o de bits de bot\u00f5es pressionados Lendo peda\u00e7osContinue reading “Escrevendo em Assembly para Sega Genesis #5”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[61,52],"tags":[165,172,174],"class_list":["post-3011","post","type-post","status-publish","format-standard","hentry","category-techie","category-tutorials","tag-asm","tag-roms","tag-vasm","entry"],"translation":{"provider":"WPGlobus","version":"3.0.2","language":"pt","enabled_languages":["en","ru","zh","de","fr","ja","pt"],"languages":{"en":{"title":true,"content":true,"excerpt":false},"ru":{"title":true,"content":true,"excerpt":false},"zh":{"title":true,"content":true,"excerpt":false},"de":{"title":true,"content":true,"excerpt":false},"fr":{"title":true,"content":true,"excerpt":false},"ja":{"title":true,"content":true,"excerpt":false},"pt":{"title":true,"content":true,"excerpt":false}}},"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/demensdeum.com\/blog\/pt\/wp-json\/wp\/v2\/posts\/3011","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/demensdeum.com\/blog\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/demensdeum.com\/blog\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/demensdeum.com\/blog\/pt\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/demensdeum.com\/blog\/pt\/wp-json\/wp\/v2\/comments?post=3011"}],"version-history":[{"count":9,"href":"https:\/\/demensdeum.com\/blog\/pt\/wp-json\/wp\/v2\/posts\/3011\/revisions"}],"predecessor-version":[{"id":3894,"href":"https:\/\/demensdeum.com\/blog\/pt\/wp-json\/wp\/v2\/posts\/3011\/revisions\/3894"}],"wp:attachment":[{"href":"https:\/\/demensdeum.com\/blog\/pt\/wp-json\/wp\/v2\/media?parent=3011"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/demensdeum.com\/blog\/pt\/wp-json\/wp\/v2\/categories?post=3011"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/demensdeum.com\/blog\/pt\/wp-json\/wp\/v2\/tags?post=3011"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}