{"id":4060,"date":"2018-05-07T23:32:09","date_gmt":"2018-05-07T15:32:09","guid":{"rendered":"http:\/\/www.bookcard.net\/wordpress\/?p=4060"},"modified":"2018-10-14T21:14:04","modified_gmt":"2018-10-14T13:14:04","slug":"opengl_bezier_surface","status":"publish","type":"post","link":"https:\/\/www.bookcard.net\/wordpress\/opengl_bezier_surface\/","title":{"rendered":"OpenGL\u4e4b\u8c9d\u8cfd\u723e(Bezier)\u66f2\u9762"},"content":{"rendered":"
\"\"<\/a>
OpenGL\u8c9d\u8cfd\u723e(Bezier)\u66f2\u9762<\/figcaption><\/figure>\n

\u8c9d\u8cfd\u723e(Bezier)\u300e\u66f2\u9762\u300f\u8207\u300e\u66f2\u7dda<\/a>\u300f\u76f8\u6bd4\u4e0d\u540c\u4e4b\u8655\u5728\u65bc\u591a\u5497v\u7a7a\u9593\u57df.\u66f2\u9762\u51fd\u5f0fs(u,v).\u66f2\u9762<\/strong>\u6f14\u793a\u7a0b\u5f0f\u6309\u7a7a\u683c\u9375\u5728\u7dda\u6846\u3001\u586b\u5145\u3001\u7d0b\u7406\u6a21\u5f0f\u4e2d\u5207\u63db:\u4e0b\u8f09<\/a><\/p>\n

1.\u5c0d\u66f2\u9762\u9032\u884c\u67f5\u683c\u6620\u5c04<\/p>\n

void glMap2f(GLenum target,GLfloat u1,GLfloat u2,GLint ustride,GLint uorder,GLfloat v1,GLfloat v2,GLint vstride,GLint vorder,const GLfloat *points);<\/p>\n

\u51fd\u5f0f\u793a\u4f8b:<\/p>\n

glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3,u,\u00a0 0,1, 3v,3,\u00a0 (GLfloat<\/em>)bezier->control_array);<\/p>\n\n\n\n\n\n\n\n\n\n\n\n
\u53c3\u6578<\/td>\n\u7c21\u4ecb<\/td>\n<\/tr>\n
target<\/td>\n\u63a7\u5236\u9ede\u985e\u578b<\/strong><\/td>\n<\/tr>\n
u1,u2<\/td>\nu<\/strong>\u7a7a\u9593\u57df\u53c3\u6578\u7684\u5b9a\u7fa9\u57df(u1~u2)<\/strong><\/td>\n<\/tr>\n
ustride<\/td>\nu<\/strong>\u7a7a\u9593\u57df\u9802\u9ede<\/strong>\u8de8\u5ea6<\/td>\n<\/tr>\n
uorder<\/td>\nu<\/strong>\u7a7a\u9593\u57df\u9802\u9ede\u500b\u6578<\/strong><\/td>\n<\/tr>\n
v1, v2<\/td>\nv<\/strong>\u7a7a\u9593\u57df\u53c3\u6578\u7684\u5b9a\u7fa9\u57df(u1~u2)<\/strong><\/td>\n<\/tr>\n
vstride<\/td>\nv<\/strong>\u7a7a\u9593\u57df\u9802\u9ede<\/strong>\u8de8\u5ea6<\/td>\n<\/tr>\n
vorder<\/td>\nv<\/strong>\u7a7a\u9593\u57df\u9802\u9ede\u500b\u6578<\/strong><\/td>\n<\/tr>\n
points<\/td>\n\u5b9a\u9ede\u6578\u7d44<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u00a0<\/strong><\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n
\u63a7\u5236\u9ede\u985e\u578b(<\/strong>target)<\/td>\n\u7c21\u4ecb<\/strong><\/td>\n<\/tr>\n
GL_MAP1_VERTEX_3<\/strong><\/td>\n\u9802\u9ede\u5ea7\u6a19(x,y,z)<\/strong><\/td>\n<\/tr>\n
GL_MAP1_VERTEX_4<\/strong><\/td>\n\u9802\u9ede\u5ea7\u6a19(x,y,z,w)<\/strong><\/td>\n<\/tr>\n
GL_MAP1_INDEX<\/strong><\/td>\n\u984f\u8272\u7d22\u5f15<\/strong><\/td>\n<\/tr>\n
GL_MAP1_COLOR_4<\/strong><\/td>\n\u984f\u8272\u503c(RGBA)<\/strong><\/td>\n<\/tr>\n
GL_MAP1_NORMAL<\/strong><\/td>\n\u6cd5\u7dda\u5ea7\u6a19<\/strong><\/td>\n<\/tr>\n
GL_MAP1_TEXTURE_COORD_1<\/strong><\/td>\n\u7d0b\u7406\u5ea7\u6a19(s)<\/strong><\/td>\n<\/tr>\n
GL_MAP1_TEXTURE_COORD_2<\/strong><\/td>\n\u7d0b\u7406\u5ea7\u6a19(s,t)<\/strong><\/td>\n<\/tr>\n
GL_MAP1_TEXTURE_COORD_3<\/strong><\/td>\n\u7d0b\u7406\u5ea7\u6a19(s,t,r)<\/strong><\/td>\n<\/tr>\n
GL_MAP1_TEXTURE_COORD_4<\/strong><\/td>\n\u7d0b\u7406\u5ea7\u6a19(s,t,r,g)<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

2.\u555f\u7528\u8c9d\u8cfd\u723e(Bezier)\u66f2\u9762<\/p>\n

glEnable(GL_MAP2_VERTEX_3);<\/p>\n

3.\u5b9a\u7fa9\u5b9a\u7fa9\u5747\u52fb\u7684\u67f5\u683c,\u4e26\u8a2d\u7f6e\u9593\u9694\u500b\u6578<\/p>\n

void glMapGrid2f(GLint un,GLfloat u1,GLfloat u2,GLint vn,GLfloat v1,GLfloat v2);<\/p>\n

\u51fd\u5f0f\u793a\u4f8b:<\/p>\n

glMapGrid2f(10,0, 10, 10, 0, 10);<\/p>\n\n\n\n\n\n\n\n\n\n
\u53c3\u6578<\/td>\n\u7c21\u4ecb<\/strong><\/td>\n<\/tr>\n
un<\/td>\nu\u57df[u1~u2]\u9593\u9694\u500b\u6578,\u5fc5\u9808\u70ba\u6b63<\/td>\n<\/tr>\n
u1<\/td>\nu1=0<\/td>\n<\/tr>\n
u2<\/td>\nu2=un<\/td>\n<\/tr>\n
vn<\/td>\nv\u57df[v1~v2]\u9593\u9694\u500b\u6578,\u5fc5\u9808\u70ba\u6b63<\/td>\n<\/tr>\n
v1<\/td>\nv1=0<\/td>\n<\/tr>\n
v2<\/td>\nv2=vn<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \n
  1. \u6839\u64da\u67f5\u683c\u8a2d\u7f6e\u7e6a\u88fd\u66f2\u9762<\/li>\n<\/ol>\n

    void glEvalMesh2(GLenum mode,GLint i1,GLint i2,GLint j1,GLint j2);<\/p>\n

    \u51fd\u5f0f\u793a\u4f8b:<\/p>\n

    glEvalMesh2(GL_FILL, 0, 10, 0, 10);<\/p>\n\n\n\n\n\n\n
    \u53c3\u6578<\/td>\n\u7c21\u4ecb<\/td>\n<\/tr>\n
    mode<\/td>\n\u7e6a\u756b\u6a21\u5f0f<\/p>\n

    GL_POINT:\u9ede<\/p>\n

    GL_LINE:\u76f4\u7dda<\/p>\n

    GL_FILL:\u586b\u5145<\/td>\n<\/tr>\n

    i1,i2<\/td>\nu\u7a7a\u9593\u57df\u7684\u7bc4\u570d<\/td>\n<\/tr>\n
    j1,j2<\/td>\nv\u7a7a\u9593\u57df\u7684\u7bc4\u570d<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    5.\u70ba\u66f2\u9762\u751f\u6210\u6cd5\u7dda\u7528\u65bc\u5149\u7167<\/p>\n

    glEnable(GL_AUTO_NORMAL);<\/p>\n

    6.\u5c0d\u66f2\u9762\u9032\u884c\u7d0b\u7406\u6620\u5c04<\/p>\n

    glMap2f(GL_MAP2_TEXTURE_COORD_2, 0,1,2, 2,0,1, 4,2,(GLfloat*)bezier->texture_coord);<\/p>\n\n\n\n\n\n\n\n\n\n\n\n
    \u5c0d\u66f2\u9762\u9032\u884c\u7d0b\u7406\u6620\u5c04glMap2f()<\/td>\n\u7c21\u4ecb<\/td>\n<\/tr>\n
    target<\/td>\n\u7d0b\u7406\u5ea7\u6a19(s,t):<\/strong>GL_MAP2_TEXTURE_COORD_2(\u7747\u4e0a\u8868)<\/td>\n<\/tr>\n
    u1,u2<\/td>\ns\u7a7a\u9593\u57df:[0~1]<\/td>\n<\/tr>\n
    ustride<\/td>\ns\u7d0b\u7406\u5ea7\u6a19\u9802\u9ede<\/strong>\u8de8\u5ea6:2<\/td>\n<\/tr>\n
    uorder<\/td>\ns<\/strong>\u7a7a\u9593\u57df\u9802\u9ede\u500b\u6578:2<\/strong><\/td>\n<\/tr>\n
    v1,v2<\/td>\nt\u7a7a\u9593\u57df:[0~1]<\/td>\n<\/tr>\n
    vstride<\/td>\nt\u7d0b\u7406\u5ea7\u6a19\u9802\u9ede<\/strong>\u8de8\u5ea6:4<\/td>\n<\/tr>\n
    vorder<\/td>\nt<\/strong>\u7a7a\u9593\u57df\u9802\u9ede\u500b\u6578:2<\/strong><\/td>\n<\/tr>\n
    points<\/td>\n\u7d0b\u7406\u5ea7\u6a19:{0.0, 0.0}, {0.0, 1.0}, {1.0, 0.0}, {1.0, 1.0}<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    4.\u555f\u7528\u66f2\u9762\u7d0b\u7406\u5ea7\u6a19<\/p>\n

    glEnable(GL_MAP2_TEXTURE_COORD_2);<\/p>\n","protected":false},"excerpt":{"rendered":"

    \u8c9d\u8cfd\u723e(Bezier)\u300e\u66f2\u9762\u300f\u8207\u300e\u66f2\u7dda\u300f\u76f8\u6bd4\u4e0d\u540c\u4e4b\u8655\u5728\u65bc\u591a\u5497v\u7a7a\u9593\u57df.\u66f2\u9762\u51fd\u5f0fs(u,v).\u66f2\u9762\u6f14\u793a\u7a0b\u5f0f\u6309\u7a7a\u683c … <\/p>\n

    \u7e7c\u7e8c\u95b1\u8b80 OpenGL\u4e4b\u8c9d\u8cfd\u723e(Bezier)\u66f2\u9762<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[62],"tags":[50],"class_list":["post-4060","post","type-post","status-publish","format-standard","hentry","category-opengl","tag-opengl","entry"],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/posts\/4060","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/comments?post=4060"}],"version-history":[{"count":2,"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/posts\/4060\/revisions"}],"predecessor-version":[{"id":4105,"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/posts\/4060\/revisions\/4105"}],"wp:attachment":[{"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/media?parent=4060"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/categories?post=4060"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/tags?post=4060"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}