/*!* \file: Exp1.cpp* \date: 2020/05/29 15:04* \author: wangqi* Contact: wangq@southzn.com** \brief:** TODO: long description** \note: 实现了FT库生成字符位图，并上传到GL纹理。实现了字符位图缓存功能，多个字符图像保存在同一个纹理中。实现了简单的字体管理框架。实现了简单的加粗和倾斜效果。实现了反锯齿开关，并且兼容加粗倾斜效果。*/// OpenGL library#include <gl/glut.h>// Std misc#include <map>#include <vector>// FreeType library#include <ft2build.h>#include FT_FREETYPE_H#include FT_BITMAP_H#include FT_OUTLINE_H#ifdef CreateFont#undef CreateFont#endiftypedef unsigned char byte;class CFontManager //字体管理器：管理了一个字体库{public:CFontManager();~CFontManager();// 初始化bool initialize(void);// 释放void release(void);/*!* \brief: createFont 创建字体** \param: filename 字体文件的路径* \param: face* \param: tall 高度* \param: bold 加粗* \param: italic 是否斜体* \param: antialias 是否抗锯齿* \returns: int* \author: wangqi* \date: 2020/06/02 14:16** TODO:**/int createFont(const char *filename, int face, int tall, bool bold, bool italic, bool antialias);// 得到字符信息bool getCharInfo(int font_index, int code, int *wide, int *tall, int *horiBearingX, int *horiBearingY, int *horiAdvance, GLuint *texture, float coords[]);// 得到字体的高度int getFontTall(int font_index);private:struct glyphMetrics //字形度量{int width; //宽度int height; //长度int horiBearingX;int horiBearingY;int horiAdvance;//int vertBearingX;//int vertBearingY;//int vertAdvance;};class CFont //字体{public:CFont();~CFont();/*!* \brief: create 创建字体** \param: library FT库。需要提前FT_Init_FreeType* \param: filename 字体文件的路径* \param: face_index Face下标* \param: tall 高度* \param: bold 是否加粗* \param: italic 是否斜体* \param: antialias 是否抗锯齿* \returns: bool* \author: wangqi* \date: 2020/06/02 14:13** TODO:**/bool create(FT_Library library, const char *filename, FT_Long face_index,int tall, bool bold, bool italic, bool antialias);// 释放void release(void);// 得到字符串信息bool getCharInfo(int code, glyphMetrics *metrics, GLuint *texture, float coords[]);// 得到字符高度int getFontTall(void);private:// 加载字符bool loadChar(int code, glyphMetrics *metrics);class CChar //渲染之后的字符{public:// 设置信息void setInfo(glyphMetrics *metrics);// 得到信息void getInfo(glyphMetrics *metrics, GLuint *texture, float coords[]);public:int m_code; //编码GLuint m_texture; //纹理float m_coords[4]; //坐标：left top right bottomprivate:glyphMetrics m_metrics;};class CPage //页面:纹理=1:1。一个纹理中管理着多个字符{public:CPage();~CPage();/*!* \brief: append 加当前字体加入这个纹理** \param: wide 宽度* \param: tall 高度* \param: rgba 字体的内容* \param: coords 字体在当前纹理中的坐标* \returns: bool* \author: wangqi* \date: 2020/06/02 14:36** TODO:**/bool append(int wide, int tall, byte *rgba, float coords[]);GLuint getTexture(void); //得到纹理private:GLuint m_texture; //纹理int m_wide; //宽度int m_tall; //高度int m_posx;int m_posy;int m_maxCharTall;};typedef std::map<int, CChar *> TCharMap;//键值对：找到字符的位置//key: 字符//value: 字符的信息FT_Library m_library;FT_Face m_face;bool m_antialias;bool m_bold;int m_tall;int m_rgbaSize;GLubyte *m_rgba;TCharMap m_chars;std::vector<CPage *> m_pages;};FT_Library m_library;std::vector<CFont *> m_fonts; //一个字体库有多个字体};//------------------------------------------------------------// CFont//------------------------------------------------------------CFontManager::CFont::CFont(){m_face = NULL;m_rgba = NULL;m_antialias = false;m_bold = false;m_tall = 0;}CFontManager::CFont::~CFont(){release();}bool CFontManager::CFont::create(FT_Library library, const char *filename, FT_Long face_index,int tall, bool bold, bool italic, bool antialias){FT_Error err;if(tall > 256){// Bigger than a page sizereturn false;}// 得到字符信息if((err = FT_New_Face(library, filename, face_index, &m_face)) != FT_Err_Ok){printf("FT_New_Face() Error %d\n", err);return false;}// 设置像素if((err = FT_Set_Pixel_Sizes(m_face, 0, tall)) != FT_Err_Ok){printf("FT_Set_Pixel_Sizes() Error %d\n", err);return false;}//m_rgbaSize = (tall * 2) * tall * 4; //源代码是*2，但是觉得博主写错了m_rgbaSize = (tall) * tall * 4; //高*宽*4。但位图的高宽相同，故可以高*高*4；4代表RGBA四个通道m_rgba = new GLubyte[m_rgbaSize];if(m_rgba == NULL){return false;}m_library = library;m_antialias = antialias;m_bold = bold;m_tall = tall;if(italic) //是否抗锯齿{FT_Matrix m;m.xx = 0x10000L;m.xy = 0.5f * 0x10000L;m.yx = 0;m.yy = 0x10000L;FT_Set_Transform(m_face, &m, NULL);}return true;}void CFontManager::CFont::release(void){FT_Error err;if(m_face){if((err = FT_Done_Face(m_face)) != FT_Err_Ok){printf("FT_Done_Face() Error %d\n", err);}m_face = NULL;}if(m_rgba){delete[] m_rgba;m_rgba = NULL;}for(TCharMap::iterator it = m_chars.begin(); it != m_chars.end(); it++){delete it->second;it->second = NULL;}m_chars.clear();for(size_t i = 0; i < m_pages.size(); i++){delete m_pages[i];m_pages[i] = NULL;}m_pages.clear();}bool CFontManager::CFont::getCharInfo(int code, glyphMetrics *metrics, GLuint *texture, float coords[]){// 记忆化搜索TCharMap::iterator it = m_chars.find(code); //根据code获取CCharif(it != m_chars.end()) //找到{// 得到绘制信息it->second->getInfo(metrics, texture, coords); //字符、纹理、 坐标return true;}// 没有找到glyphMetrics gm;if(loadChar(code, &gm) == false) //加载字符{return false;}CChar *ch = new CChar();ch->m_code = code;ch->setInfo(&gm);// 追加到一张纸中for(size_t i = 0; i < m_pages.size(); i++){CPage *page = m_pages[i];if(page->append(gm.width, gm.height, m_rgba, ch->m_coords)){// 这张纸还放的下ch->m_texture = page->getTexture();ch->getInfo(metrics, texture, coords);m_chars.insert(TCharMap::value_type(code, ch));return true;}}// 之前的纸都放不下了，新建一张纸CPage *page = new CPage();if(page->append(gm.width, gm.height, m_rgba, ch->m_coords)){ch->m_texture = page->getTexture();ch->getInfo(metrics, texture, coords);m_chars.insert(TCharMap::value_type(code, ch));m_pages.push_back(page);return true;}delete ch;delete page;return false;}int CFontManager::CFont::getFontTall(void){return m_tall;}// bitmap.width 位图宽度// bitmap.rows 位图行数（高度）// bitmap.pitch 位图一行占用的字节数//MONO模式每1个像素仅用1bit保存，只有黑和白。//1个byte可以保存8个像素，1个int可以保存8*4个像素。void ConvertMONOToRGBA(FT_Bitmap *source, GLubyte *rgba){GLubyte *s = source->buffer;GLubyte *t = rgba;for(GLuint y = source->rows; y > 0; y--){GLubyte *ss = s;GLubyte *tt = t;for(GLuint x = source->width >> 3; x > 0; x--){GLuint val = *ss;for(GLuint i = 8; i > 0; i--){tt[0] = tt[1] = tt[2] = tt[3] = (val & (1 << (i - 1))) ? 0xFF : 0x00;tt += 4;}ss += 1;}GLuint rem = source->width & 7;if(rem > 0){GLuint val = *ss;for(GLuint x = rem; x > 0; x--){tt[0] = tt[1] = tt[2] = tt[3] = (val & 0x80) ? 0xFF : 0x00;tt += 4;val <<= 1;}}s += source->pitch;t += source->width * 4; //pitch}}//GRAY模式1个像素用1个字节保存。void ConvertGRAYToRGBA(FT_Bitmap *source, GLubyte *rgba){for(GLuint y = 0; y < source->rows; y++){for(GLuint x = 0; x < source->width; x++){GLubyte *s = &source->buffer[(y * source->pitch) + x];GLubyte *t = &rgba[((y * source->pitch) + x) * 4];t[0] = t[1] = t[2] = 0xFF;t[3] = *s;}}}bool CFontManager::CFont::loadChar(int code, glyphMetrics *metrics){FT_Error err;FT_UInt glyph_index = FT_Get_Char_Index(m_face, (FT_ULong)code); //得到下标if(glyph_index > 0){//将一个字形图像装到字形槽中if((err = FT_Load_Glyph(m_face, glyph_index, FT_LOAD_DEFAULT)) == FT_Err_Ok){FT_GlyphSlot glyph = m_face->glyph; //获得图形信息// 模式：抗锯齿为256级灰度;FT_RENDER_MODE_MONO黑白FT_Render_Mode render_mode = m_antialias ? FT_RENDER_MODE_NORMAL : FT_RENDER_MODE_MONO;if(m_antialias && m_bold) //加粗{if((err = FT_Outline_EmboldenXY(&glyph->outline, 60, 60)) != FT_Err_Ok){printf("FT_Outline_EmboldenXY() Error %d\n", err);}}// 得到图形信息if((err = FT_Render_Glyph(glyph, render_mode)) == FT_Err_Ok){FT_Bitmap *bitmap = &glyph->bitmap; //得到位图switch(bitmap->pixel_mode) //像素模式{case FT_PIXEL_MODE_MONO: //黑白{if(!m_antialias && m_bold){// 加粗if((err = FT_Bitmap_Embolden(m_library, bitmap, 60, 0)) != FT_Err_Ok){printf("FT_Bitmap_Embolden() Error %d\n", err);}}// 将黑白转成RGBAConvertMONOToRGBA(bitmap, m_rgba);break;}case FT_PIXEL_MODE_GRAY: //灰度{ConvertGRAYToRGBA(bitmap, m_rgba); //灰度转RGBAbreak;}default:{memset(m_rgba, 0xFF, m_rgbaSize);break;}}metrics->width = bitmap->width;metrics->height = bitmap->rows;metrics->horiBearingX = glyph->bitmap_left;metrics->horiBearingY = glyph->bitmap_top;metrics->horiAdvance = glyph->advance.x >> 6;return true;}else{printf("FT_Render_Glyph() Error %d\n", err);}}else{printf("FT_Load_Glyph() Error %d\n", err);}}memset(metrics, 0, sizeof(glyphMetrics));return false;}//------------------------------------------------------------// CChar//------------------------------------------------------------void CFontManager::CFont::CChar::setInfo(glyphMetrics *metrics){memcpy(&m_metrics, metrics, sizeof(glyphMetrics));}void CFontManager::CFont::CChar::getInfo(glyphMetrics *metrics, GLuint *texture, float coords[]){memcpy(metrics, &m_metrics, sizeof(glyphMetrics));*texture = m_texture;memcpy(coords, m_coords, sizeof(float) * 4);}//------------------------------------------------------------// CPage 开辟一页的纹理，来存放多个字符//------------------------------------------------------------CFontManager::CFont::CPage::CPage() //一页对应一个纹理{m_wide = m_tall = 256; //高m_posx = m_posy = 0;// In a line, for a max height characterm_maxCharTall = 0;glGenTextures(1, &m_texture); // Using your API hereglBindTexture(GL_TEXTURE_2D, m_texture);glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, m_wide, m_tall, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);}CFontManager::CFont::CPage::~CPage(){// free the texture}bool CFontManager::CFont::CPage::append(int wide, int tall, byte *rgba, float coords[]){if(m_posy + tall > m_tall){// not enough line space in this pagereturn false;}// If this line is full ...if(m_posx + wide > m_wide){int newLineY = m_posy + m_maxCharTall;if(newLineY + tall > m_tall){// No more space for new line in this page, should allocate a new onereturn false;}// Begin in new linem_posx = 0;m_posy = newLineY;// Resetm_maxCharTall = 0;}glBindTexture(GL_TEXTURE_2D, m_texture);glTexSubImage2D(GL_TEXTURE_2D, 0, m_posx, m_posy, wide, tall, GL_RGBA, GL_UNSIGNED_BYTE, rgba);// 该字符的位置coords[0] = m_posx / (float)m_wide; // leftcoords[1] = m_posy / (float)m_tall; // topcoords[2] = (m_posx + wide) / (float)m_wide; // rightcoords[3] = (m_posy + tall) / (float)m_tall; // bottomm_posx += wide;if(tall > m_maxCharTall){m_maxCharTall = tall;}return true;}GLuint CFontManager::CFont::CPage::getTexture(void){return m_texture;}//------------------------------------------------------------// CFontManager//------------------------------------------------------------CFontManager::CFontManager(){m_library = NULL;}CFontManager::~CFontManager(){release();}bool CFontManager::initialize(void){FT_Error err;if((err = FT_Init_FreeType(&m_library)) != FT_Err_Ok) //初始化一个库{printf("FT_Init_FreeType() Error %d\n", err);return false;}return true;}void CFontManager::release(void){FT_Error err;for(size_t i = 0; i < m_fonts.size(); i++){delete m_fonts[i];m_fonts[i] = NULL;}m_fonts.clear();if((err = FT_Done_FreeType(m_library)) != FT_Err_Ok){printf("FT_Done_FreeType() Error %d\n");}}int CFontManager::createFont(const char *filename, int face, int tall, bool bold,bool italic, bool antialias){// 新建字体CFont *font = new CFont();if(font->create(m_library, filename, face, tall, bold, italic, antialias) != true){delete font; //创建失败return 0;}// 放入字体数组，进行管理m_fonts.push_back(font);return m_fonts.size();}#define CONVERT_FONT_INDEX(x) (((x) < 1 || (x) > (int)m_fonts.size()) ? -1 : (x) - 1)bool CFontManager::getCharInfo(int font_index, int code, int *wide, int *tall, int *horiBearingX, int *horiBearingY, int *horiAdvance, GLuint *texture, float coords[]){int i = CONVERT_FONT_INDEX(font_index); //转换字符的下标if(i == -1){return false;}CFont *font = m_fonts[i]; //获得字体glyphMetrics metrics; //绘制信息if(font->getCharInfo(code, &metrics, texture, coords) == false) //获得绘制信息{return false;}// 解析绘制信息*wide = metrics.width;*tall = metrics.height;*horiBearingX = metrics.horiBearingX;*horiBearingY = metrics.horiBearingY;*horiAdvance = metrics.horiAdvance;return true;}int CFontManager::getFontTall(int font_index){int i = CONVERT_FONT_INDEX(font_index);if(i == -1){return false;}CFont *font = m_fonts[i];return font->getFontTall();}CFontManager g_FontManager;int char_font;void init(void){// 清除颜色glClearColor(0.0, 0.0, 0.0, 0.0);// 混合模式glEnable(GL_BLEND);glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);// 初始化一个库g_FontManager.initialize();// 创建字体，返回字体集的个数char_font = g_FontManager.createFont("C:\\WINDOWS\\Fonts\\simhei.ttf",0,32, //字体高度false,false,true);if(char_font == 0)//创建失败{printf("createFont failed\n");}}wchar_t ciphertext[] ={L"你好吗？\n"L"温馨提示：\n"L"不要忘记明天上午 7:30-12:00 在公司的体检哦~\n"L"体检前一天不要暴饮暴食，不要喝酒，不要进食太甜太咸的食物\n"L"以免影响体检结果\n"L"晚上10点后一般要求禁食。\n"L"体检当天早晨千万不要吃早餐！\n"L"不要吃早餐！\n"L"不要吃早餐！\n"L"绘制位置。忘记了，可费解为无法\n"};//#define DRAW_PAGE/*!* \brief: draw_string** \param: x 绘制位置* \param: y* \param: font 字体* \param: string 字符串* \returns: void* \author: wangqi* \date: 2020/06/02 14:18** TODO:**/void draw_string(int x, int y, int font_index, wchar_t *string){if(!font_index) //字体{return;}int tall = g_FontManager.getFontTall(font_index); //得到字符高：初始化字体时设置的// 绘制的初始位置int dx = x;int dy = y;GLuint sglt = 0; //纹理编号，第几张纸while(*string) // 遍历字符串{if(*string == L'\n') //回车{string++;dx = x; //绘制的初始位置xdy += tall + 2; //行间距continue;}int cw, ct; //宽度、高度int bx, by, av;GLuint glt; //该字符所在的纸张float crd[4]; //该字符的坐标//得到字符信息if(!g_FontManager.getCharInfo(font_index, *string, &cw, &ct, &bx, &by, &av, &glt, crd)){string++;continue;}//大多数情况下多个字符都在同一个纹理中，避免频繁绑定纹理，可以提高效率if(glt != sglt) //和原来的不一样，则绑定当前的纹理{glBindTexture(GL_TEXTURE_2D, glt); //绑定纹理sglt = glt;}int px = dx + bx;int py = dy - by;// 开始绘制四边形glBegin(GL_QUADS);// 第一个点glTexCoord2f(crd[0], crd[1]); //指定该字符在纹理中的坐标，阈值为[0, 1]glVertex3f(px, py, 0.0f); //对应画布中的位置// 第二个点glTexCoord2f(crd[2], crd[1]);glVertex3f(px + cw, py, 0.0f);// 第三个点glTexCoord2f(crd[2], crd[3]);glVertex3f(px + cw, py + ct, 0.0f);// 第四个点glTexCoord2f(crd[0], crd[3]);glVertex3f(px, py + ct, 0.0f);// 结束绘制glEnd();dx += av;string++;}}void draw_page_texture(int x, int y, GLuint glt){if(!glt){glDisable(GL_TEXTURE_2D); //关闭glColor4f(0.2, 0.2, 0.2, 1.0);}else{glEnable(GL_TEXTURE_2D); //开启glBindTexture(GL_TEXTURE_2D, glt); //绑定纹理glColor4f(1.0, 1.0, 1.0, 1.0);}int w = 256;int t = 256;glBegin(GL_QUADS);glTexCoord2f(0.0, 0.0);glVertex3f(x, y, 0.0f);glTexCoord2f(1.0, 0.0);glVertex3f(x + w, y, 0.0f);glTexCoord2f(1.0, 1.0);glVertex3f(x + w, y + t, 0.0f);glTexCoord2f(0.0, 1.0);glVertex3f(x, y + t, 0.0f);glEnd();}void display(void){// 清除缓存glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);// 开启纹理glEnable(GL_TEXTURE_2D);// 设置画笔颜色，即字体颜色glColor4f(0.0, 0.0, 1.0, 1.0);// 绘制字符串draw_string(10, 30, char_font, ciphertext);// 绘制整个纹理draw_page_texture(10, 350, 0); //绘制一个背景draw_page_texture(10, 350, 1); //绘制第一张纸（即第一个纹理）draw_page_texture(276, 350, 0); //绘制一个背景draw_page_texture(276, 350, 2); //绘制第二张纸（即第二个纹理）glutSwapBuffers();glutPostRedisplay();}void reshape(int width, int height){glViewport(0, 0, width, height);glMatrixMode(GL_PROJECTION);glLoadIdentity();gluOrtho2D(0, width, height, 0);glMatrixMode(GL_MODELVIEW);}void keyboard(unsigned char key, int x, int y){}void main(int argc, char **argv){glutInitWindowPosition(200, 200);glutInitWindowSize(1200, 680);glutInit(&argc, argv);glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH | GLUT_STENCIL);glutCreateWindow("FreeType OpenGL");init();glutDisplayFunc(display);glutReshapeFunc(reshape);glutKeyboardFunc(keyboard);glutMainLoop();}
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