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Hi everyone : 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 exam ple code showing the problem, change the value of TEST_PANGO_CAIRO_SHOW_LAYOUT_LINE to run the program, you will see that if paint the text line by line, there will be blank at the end of the picture. 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? 矗??康瓤?棺杞兀?÷窒蚪?蟹墒欢?ァ?; 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"); // call cairo_move_to to remove the effect of baseline's position 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); &nb sp; 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; } Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. Sign up now. Hotmail: Trusted email with powerful SPAM protection. Sign up now. Hotmail: Powerful Free email with security by Microsoft. Get it now. |