{"id":4054,"date":"2018-05-05T20:47:06","date_gmt":"2018-05-05T12:47:06","guid":{"rendered":"http:\/\/www.bookcard.net\/wordpress\/?p=4054"},"modified":"2018-10-14T21:19:04","modified_gmt":"2018-10-14T13:19:04","slug":"opengl_bezier_curve","status":"publish","type":"post","link":"https:\/\/www.bookcard.net\/wordpress\/opengl_bezier_curve\/","title":{"rendered":"OpenGL\u4e4b\u8c9d\u8cfd\u723e(Bezier)\u66f2\u7dda"},"content":{"rendered":"
\"\"<\/a>
OpenGL\u8c9d\u8cfd\u723e(Bezier)\u66f2\u7dda<\/figcaption><\/figure>\n

OpenGL<\/strong>\u652f\u6301\u8c9d\u8cfd\u723e<\/strong>(Bezier)<\/strong>\u66f2\u7dda\u7e6a\u756b<\/strong>,<\/strong>\u8c9d\u8cfd\u723e\u66f2\u7dda<\/strong>\u7531\u8d77\u9ede<\/strong>,<\/strong>\u7d42\u9ede\u548c\u63a7\u5236\u9ede\u7d44\u6210<\/strong>,<\/strong>\u4e26\u4e14\u5177\u6709\u5e73\u6ed1\u7684\u904b\u52d5\u8ecc\u8de1<\/strong>.<\/strong>\u63a7\u5236\u9ede\u7528\u65bc\u5b9a\u7fa9\u66f2\u7dda\u7684\u5f62\u72c0<\/strong>,<\/strong>\u50cf\u78c1\u77f3\u5c07\u66f2\u7dda\u5411\u63a7\u5236\u9ede\u7684\u4f4d\u7f6e\u5438\u5f15<\/strong>.<\/strong>\u4e0a\u5716\u7684\u6f14\u793a\u7a0b\u5f0f\u901a\u904e\u6ed1\u9f20\u9ede\u9078\u5c4f\u5e55\u653e\u7f6e\u300e\u63a7\u5236\u9ede\u300f\u7e6a\u756b<\/strong>\u8c9d\u8cfd\u723e<\/strong>(Bezier)<\/strong>\u66f2\u7dda<\/strong>.<\/strong>\u6309<\/strong>ESC<\/strong>\u9375\u6e05\u7a7a\u300e\u63a7\u5236\u9ede\u300f<\/strong>:<\/strong>\u4e0b\u8f09<\/strong><\/a><\/p>\n

1.<\/strong>\u8a2d\u7f6e<\/strong>\u8c9d\u8cfd\u723e<\/strong>(Bezier)<\/strong>\u66f2\u7dda<\/strong><\/p>\n

void glMap1f(GLenum target,GLfloat u1,GLfloat u2,GLint stride,GLint order,const GLfloat *points);<\/strong><\/p>\n\n\n\n\n\n\n\n\n
\u53c3\u6578<\/strong><\/td>\n\u7c21\u4ecb<\/strong><\/td>\n<\/tr>\n
target<\/strong><\/td>\n\u63a7\u5236\u9ede\u985e\u578b<\/strong><\/td>\n<\/tr>\n
u1, u2<\/strong><\/td>\nu<\/strong>\u53c3\u6578<\/strong>\u7684\u5b9a\u7fa9\u57df<\/strong>(0~1)<\/strong><\/td>\n<\/tr>\n
stride<\/strong><\/td>\n\u9802\u9ede<\/strong>\u8de8\u5ea6<\/td>\n<\/tr>\n
order<\/strong><\/td>\n\u66f2\u7dda<\/strong>\u9802\u9ede\u500b\u6578<\/strong>(<\/strong>\u7531\u8d77\u9ede<\/strong>,<\/strong>\u7d42\u9ede\u548c\u63a7\u5236\u9ede\u7d44\u6210<\/strong>)<\/strong><\/td>\n<\/tr>\n
points<\/strong><\/td>\n\u6307\u5411<\/strong>\u66f2\u7dda<\/strong>\u9802\u9ede\u6578\u7d44\u7531<\/strong>(<\/strong>\u8d77\u9ede<\/strong>,<\/strong>\u7d42\u9ede\u548c\u63a7\u5236\u9ede\u7d44\u6210<\/strong>)<\/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(target)<\/strong><\/td>\n\u7c21\u4ecb<\/strong><\/td>\n<\/tr>\n
GL_MAP1_VERTEX_3<\/strong><\/td>\n\u9802\u9ede\u5ea7\u6a19<\/strong>(x,y,z)<\/strong><\/td>\n<\/tr>\n
GL_MAP1_VERTEX_4<\/strong><\/td>\n\u9802\u9ede\u5ea7\u6a19<\/strong>(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<\/strong>(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<\/strong>(s)<\/strong><\/td>\n<\/tr>\n
GL_MAP1_TEXTURE_COORD_<\/strong>2<\/strong><\/td>\n\u7d0b\u7406\u5ea7\u6a19<\/strong>(s,t)<\/strong><\/td>\n<\/tr>\n
GL_MAP1_TEXTURE_COORD_<\/strong>3<\/strong><\/td>\n\u7d0b\u7406\u5ea7\u6a19<\/strong>(s,t,r)<\/strong><\/td>\n<\/tr>\n
GL_MAP1_TEXTURE_COORD_<\/strong>4<\/strong><\/td>\n\u7d0b\u7406\u5ea7\u6a19<\/strong>(s,t,r,g)<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

2.<\/strong>\u555f\u7528\u63a7\u5236\u9ede<\/strong><\/p>\n

glEnable(GL_MAP1_VERTEX_3);<\/strong><\/p>\n

3.<\/strong>\u73fe\u5728\u53ef\u4ee5\u7e6a\u756b\u66f2\u7dda<\/strong>,<\/strong>\u4ee5<\/strong>100<\/strong>\u689d\u76f4\u7dda\u7e6a\u756b<\/strong>\u8c9d\u8cfd\u723e<\/strong>(Bezier)<\/strong>\u66f2\u7dda<\/strong>,<\/strong>\u4ee5\u5747\u7b49\u9593\u9694\u7e6a\u756b<\/strong>.<\/strong><\/p>\n

glBegin(GL_LINE_STRIP);<\/strong><\/p>\n

for (i = 0; i <= 100; ++i)<\/strong><\/p>\n

glEvalCoord1f((float)i \/ 100.0f);<\/strong><\/p>\n

glEnd();<\/strong><\/p>\n

\u4e0a\u9762\u7684\u4ee3\u78bc\u53ef\u4ee5\u7c21\u5316\u70ba<\/strong><\/p>\n

glMapGrid1d(100, 0.0f, 1.0f);\/\/ <\/strong>\u5b9a\u7fa9\u5b9a\u7fa9\u5747\u52fb\u7684\u9593\u683c<\/strong><\/p>\n

glEvalMesh1(GL_LINE,0, 100);\/\/ <\/strong>\u7e6a\u88fd\u66f2\u7dda<\/strong><\/p>\n

4.<\/strong>\u5b8c\u6210\u7e6a\u756b\u5f8c\u9700\u8981\u7e6a\u756b\u63a7\u5236\u9ede<\/strong><\/p>\n

glPointSize(5);<\/strong><\/p>\n

glBegin(GL_POINTS);<\/strong><\/p>\n

for (i = 0; i < bezier->countol_count; ++i)<\/strong><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 glVertex3fv(bezier->control_array[i].M);<\/strong><\/p>\n

glEnd();<\/strong><\/p>\n

\u00a0<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

OpenGL\u652f\u6301\u8c9d\u8cfd\u723e(Bezier)\u66f2\u7dda\u7e6a\u756b,\u8c9d\u8cfd\u723e\u66f2\u7dda\u7531\u8d77\u9ede,\u7d42\u9ede\u548c\u63a7\u5236\u9ede\u7d44\u6210,\u4e26\u4e14\u5177\u6709\u5e73\u6ed1\u7684\u904b\u52d5\u8ecc\u8de1.\u63a7 … <\/p>\n

\u7e7c\u7e8c\u95b1\u8b80 OpenGL\u4e4b\u8c9d\u8cfd\u723e(Bezier)\u66f2\u7dda<\/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-4054","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\/4054","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=4054"}],"version-history":[{"count":3,"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/posts\/4054\/revisions"}],"predecessor-version":[{"id":4106,"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/posts\/4054\/revisions\/4106"}],"wp:attachment":[{"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/media?parent=4054"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/categories?post=4054"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bookcard.net\/wordpress\/wp-json\/wp\/v2\/tags?post=4054"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}