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Hi Behdad Esfahbod : Sorry, its the first time I use the mail-list to discuss question with other people, seems I am not familiar with it and make some trouble. Thanks sincerely again for your patience and attention. I have described my problem and give an example code as following : I meet a problem with pango_layout_get_pixel_size() and pango_layout_line_get_pixel_extents(). It seems that the PangoLayout's height retrived from the previous function is not equal to PangoLine's height multiplied by the total number of lines but a little larger than it. The issue is if I get the width and height of the text through function : pango_layout_get_pixel_size(), then create a surface according to the size retrived, then paint the text line by line onto the surface, there will be a blank at the end of the surface which was not filled by any text. But if I paint the text directly through function : pang_cairo_show_layout(), the blank disappeared. In my project, I would show a large amount of text, which indicates I shouldn't accomplish painting the text in one action because it is time-consuming. Following are the example code showing the problem, and I also attached two pictures to help you understand it. Could any one give some help? Thanks a lot #include <stdio.h> #include <cairo.h> #include <pango/pangocairo.h> #define TEST_PANGO_CAIRO_SHOW_LAYOUT_LINE 0 int main(int argc, char* argv[]){ cairo_surface_t* surface = NULL; cairo_t* cr; PangoLayout* layout = NULL; PangoFontDescription* font_description = NULL; font_description = pango_font_description_from_string("Sans 27"); layout = pango_cairo_create_layout(cr); pango_layout_set_font_description(layout, font_description); char* pText = (char*)"抗战时，沦陷后的上海，在国军地下工作负责人钟国强的策划下，接二连三的日军官被刺，火车被炸，日军被击，闹得驻沪日军司令佐藤大佐，手 忙脚乱，严令情报组陈组长，三天之内，将抗日份子统统抓来。\n\n情报组黄主任奉命出勤，率领大批军警，驰抵华声戏院，将在该院演出的一班剧团男女演 员，集体抓去，只放走女主角李丹妮一人。\n\n丹妮虽获漏网，但不明其故，返家后，才发觉丈夫陈希强已参加伪组织作汉奸，不由伤痛欲绝，但犹图婉转规劝 希强，不料希强反恼羞成怒，两人大起冲突，女佣阿香闻之，立迫希强枪杀丹妮。原来阿香实为日寇潜伏希强家之情报人员，希强不敢抗命，不料丹妮己先期遁走， 两人急忙追出。 \n\n丹妮逃经后巷，遇一日本哨兵，丹妮人急智生，指说后边有强盗追来，日兵不察，将希强与阿香截住，丹妮乘机脱身。\n\n丹妮奔出后巷，见一辆汽车 驶来，急截住跳入车厢，不料司机竟是情报组的黄主任，当场大惊昏倒。\n\n丹妮醒来，已在酒店，黄主任故意挑起丹妮心事。原来丹妮在下嫁陈希强前，曾有 爱人，即钟国强，两人且有一子，现已五岁，后因国强赴后方参力抗日工作，一去无音讯，传闻已死，丹妮心灰意冷而下嫁希强。不料此时黄就告以国强未死，丹妮 大喜。\n\n丹妮遵黄之嘱，至留真照相馆找寻国强，职员老周见丹妮所说暗语不差，引往太平洋造船访国强，谁知黄已率日军跟踪而至，希图将我军地下人员， 一网打尽，尚幸国强应变有方，卒获安全撤退。\n\n但众人已视丹妮如祸水，国强也不便挽留，只得将丹妮送往苏州乡下母亲家中。不料阿香与陈希强已在恭 候，丹妮成了自投罗网。\n\n阿香将丹妮押回上海，佐藤大佐欲利用丹妮与国强之关系，刺探国军情报，谁知丹妮不允合作，佐藤无计可施，将丹妮母逮捕，迫 丹妮就范，不料丹妮母大义凛然，竟跳楼自尽。佐藤遂又命黄主任将丹妮爱子逮来，丹妮见爱子落入虎口，惟有俯首就范。\n\n佐藤又恐丹妮无法取信国强，决 居牺牲陈希强，命阿香协助丹妮，将希强击毙。果然国强阅报获悉丹妮枪击希强事，即千方百计设法与丹妮取得联络，但国强似已知丹妮事，反供给假情报，嘱丹妮 做反间谍，借刀杀人。佐藤不察，竟然中计，将黄主任拉出枪毙。 \n\n这时国强又接奉上级命令，刺杀日军南进指挥官山下板郎，及爆炸日军准备南进的军火库。谁知山下狡猾，地下人员屡击不中，国强亲自出马，亦师老无 功。最后还是陈组长设法，将丹妮献于山下。原来陈组长也属国军地下人员，潜伏日军情报部作反间谍。 \n\n丹妮击毙山下后，又随陈至军火庳埋放炸药，不料佐藤闻讯赶来，与陈发生纠缠，丹妮乘机脱身。国强率众驾小轮赶来接应，只见火光烛天，军火库耽开始 爆炸，丹妮奔逃上船，日军追来，国强等开枪阻截，小轮向江中飞驶而去。"; pango_layout_set_text(layout, pText, -1); pango_layout_set_width(layout, PANGO_SCALE * 440); pango_layout_set_wrap(layout, PANGO_WRAP_CHAR); pango_layout_set_alignment(layout, PANGO_ALIGN_LEFT); PangoLayoutLine* pLine = NULL; int LineCount = pango_layout_get_line_count(layout); printf("LineCount = %d\n", LineCount); int width = 0; int height = 0; pango_layout_get_pixel_size(layout, &width, &height); printf("layout height : %d\n", height); pLine = pango_layout_get_line_readonly(layout, 0); PangoRectangle LR; pango_layout_line_get_pixel_extents(pLine, NULL, &LR); printf("line heigth : %d\n", LR.height); surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, width, height); cr = cairo_create(surface); cairo_set_source_rgb(cr, 0.0, 0.0, 1.0); cairo_move_to(cr, 0.0, 0.0); #if TEST_PANGO_CAIRO_SHOW_LAYOUT_LINE printf("Show Layout line by line\n"); cairo_move_to(cr, 0.0, LR.height); PangoLayoutIter* pIter = pango_layout_get_iter(layout); int i = 0; for(i = 0; i < LineCount; ++i) { pLine = pango_layout_iter_get_line_readonly(pIter); pango_layout_iter_next_line(pIter); pango_cairo_show_layout_line(cr, pLine); cairo_rel_move_to(cr, 0.0, LR.height); } #else printf("show layout directly\n"); pango_cairo_show_layout(cr, layout); #endif cairo_move_to(cr, 0.0, 0.0); cairo_rectangle(cr, 0.0, 0.0, width, height); cairo_stroke(cr); cairo_destroy(cr); cairo_surface_write_to_png(surface, "hello.png"); cairo_surface_destroy(surface); g_object_unref(layout); pango_font_description_free(font_description); return 0; } Hotmail: Free, trusted and rich email service. Get it now. |