Q&A
いつもありがとうございます！！お世話になります！
#####参考サイト
リンク１ / リンク２ / リンク３
#####したいこと
テクスチャアトラスをつくってフォント表示をしたい。
(リンク１のやりかたではフォント表示できました。)
#####わからないこと
・リンク３でglTexImage2D()をもう一度呼べばテクスチャのサイズ変更可能とありますが、
const GLvoid * dataは何を指定すればいいですか？
void glTexImage2D(Lenum target,GLint level,GLint internalformat,GLsizei width,GLsizei height,GLint border,GLenum format,GLenum type,const GLvoid * data); glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, w, h, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
・char16_t* の文字数の取得はどうやってしますか？
#####コード
#pragma once #include <ft2build.h> #include FT_FREETYPE_H #include <cstdlib> #include <iostream> #include <GL/glew.h> #include <GLFW/glfw3.h> #include <vector> #include <windows.h> #include <map> #include <string.h> class Font { struct character_info { float ax; // advance.x float ay; // advance.y float bw; // bitmap.width; float bh; // bitmap.rows; float bl; // bitmap_left; float bt; // bitmap_top; float tx; // x offset of glyph in texture coordinates } ; public: FT_Library library; FT_Face face; FT_GlyphSlot g; FT_GlyphSlot slot; GLuint tex; GLuint vao; GLuint vbo; BYTE *font_buff = NULL; //文字の最長の高さ int h = 0; //文字列の長さ int w = 0; std::map<char16_t, character_info> font_data; Font(const GLuint program) { Init(program); } int Init(const GLuint program) { if (FT_Init_FreeType(&library)) { std::cout << "Could not init freetype library\n"; return 1; } LOGFONT lf; ZeroMemory(&lf, sizeof(lf)); CHOOSEFONT cf; ZeroMemory(&cf, sizeof(cf)); cf.lStructSize = sizeof(cf); cf.Flags = 0; cf.lpLogFont = &lf; // とりあえず、適当なフォントを選ぶ。 if (!ChooseFont(&cf)) { return 1; } HFONT font_h = CreateFontIndirect(&lf); if (font_h == NULL) { std::fprintf(stderr, "%s(%d): failed to load font.\n", __FILE__, __LINE__); return 1; } HDC dc_h = GetDC(NULL); HGDIOBJ old_font_h = SelectObject(dc_h, font_h); DWORD cb = GetFontData(dc_h, 0x66637474, 0, NULL, 0); if (cb != 0 && cb != GDI_ERROR) { // これなら、TTC font_buff = new BYTE[cb]; GetFontData(dc_h, 0x66637474, 0, font_buff, cb); } else { // TTFとして読んでみる。 cb = GetFontData(dc_h, 0, 0, NULL, 0); if (cb == 0 || cb == GDI_ERROR) { std::fprintf(stderr, "%s(%d): failed to load font.\n", __FILE__, __LINE__); return 1; } font_buff = new BYTE[cb]; GetFontData(dc_h, 0, 0, font_buff, cb); } if (FT_New_Memory_Face(library, font_buff, cb, 0, &face) != 0) { std::fprintf(stderr, "%s(%d): failed to load font.\n", __FILE__, __LINE__); return 1; } DeleteObject(SelectObject(dc_h, old_font_h)); ReleaseDC(NULL, dc_h); g = face->glyph; FT_Set_Pixel_Sizes(face, 0, 48); glGenVertexArrays(1, &vao); glBindVertexArray(vao); glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glActiveTexture(GL_TEXTURE0); glGenTextures(1, &tex); glBindTexture(GL_TEXTURE_2D, tex); int uniform_tex = glGetUniformLocation(program, "tex"); glUniform1i(uniform_tex, 0); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glPixelStorei(GL_UNPACK_ALIGNMENT, 1); glGenBuffers(1, &vbo); int attribute_coord = glGetAttribLocation(program, "coord"); glEnableVertexAttribArray(attribute_coord); glBindBuffer(GL_ARRAY_BUFFER, vbo); glVertexAttribPointer(attribute_coord, 4, GL_FLOAT, GL_FALSE, 0, 0); } void render_text(const char16_t *text, float x, float y, float sx, float sy) { struct point { GLfloat x; GLfloat y; GLfloat s; GLfloat t; } coords[6 * 5]; //頂点数 int n = 0; for (const char16_t *p = text; *p != '\0'; ++p) { //初めての文字だったら if (font_data.end() == font_data.find(*p)) { if (FT_Load_Glyph(face, FT_Get_Char_Index(face, *p), FT_LOAD_RENDER)) continue; //文字の書き始め font_data[*p].tx = (float)w; w += g->bitmap.width; h = Int_max(h, g->bitmap.rows); font_data[*p].ax = g->advance.x >> 6; font_data[*p].ay = g->advance.y >> 6; font_data[*p].bw = g->bitmap.width; font_data[*p].bh = g->bitmap.rows; font_data[*p].bl = g->bitmap_left; font_data[*p].bt = g->bitmap_top; glBindTexture(GL_TEXTURE_2D, tex); glTexImage2D( GL_TEXTURE_2D, 0, GL_RED, w, h, 0, GL_RED, GL_UNSIGNED_BYTE, 0 ); glTexSubImage2D( GL_TEXTURE_2D, 0, font_data[*p].tx, 0, g->bitmap.width, g->bitmap.rows, GL_ALPHA, GL_UNSIGNED_BYTE, g->bitmap.buffer ); } //描画座標 float x2 = x + font_data[*p].bl * sx; float y2 = y + font_data[*p].bt * sy; float w = font_data[*p].bw * sx; float h = font_data[*p].bh * sy; x += font_data[*p].ax * sx; y += font_data[*p].ay * sy; if (!w || !h) continue; /* coords[n++] = { x2 , y2 , font_data[*p].tx / w , 0 }; coords[n++] = { x2 + w, y2 , font_data[*p].tx / w + font_data[*p].bw / w, 0 }; coords[n++] = { x2 , y2 - h , font_data[*p].tx / w , font_data[*p].bh / h }; coords[n++] = { x2 + w, y2 , font_data[*p].tx / w + font_data[*p].bw / w, 0 }; coords[n++] = { x2 , y2 - h , font_data[*p].tx / w , font_data[*p].bh / h }; coords[n++] = { x2 + w, y2 - h , font_data[*p].tx / w + font_data[*p].bw / w, font_data[*p].bh / h };*/ coords[n++] = { x2 , y2 , font_data[*p].tx / w , 0 }; coords[n++] = { x2 , y2 - h , font_data[*p].tx / w , font_data[*p].bh / h }; coords[n++] = { x2 + w, y2 , font_data[*p].tx / w + font_data[*p].bw / w, 0 }; coords[n++] = { x2 + w, y2 , font_data[*p].tx / w + font_data[*p].bw / w, 0 }; coords[n++] = { x2 , y2 - h , font_data[*p].tx / w , font_data[*p].bh / h }; coords[n++] = { x2 + w, y2 - h , font_data[*p].tx / w + font_data[*p].bw / w, font_data[*p].bh / h }; } glBindBuffer(GL_ARRAY_BUFFER, vbo); glBufferData(GL_ARRAY_BUFFER, sizeof coords, coords, GL_DYNAMIC_DRAW); glBindVertexArray(vao); glDrawArrays(GL_TRIANGLES, 0, n); } void display(const GLuint program, GLFWwindow *const window) { glClearColor(1, 1, 1, 1); glClear(GL_COLOR_BUFFER_BIT); GLfloat black[4] = { 0, 0, 0, 1 }; int uniform_color = glGetUniformLocation(program, "color"); glUniform4fv(uniform_color, 1, black); float sx = (2.0 / 640) * 0.5; float sy = (2.0 / 480) * 0.5; render_text(u"フォントの", -1 + 8 * sx, 1 - 50 * sy, sx, sy); render_text(u"openg", -1 + 8.5 * sx, 1 - 100.5 * sy, sx, sy); glfwSwapBuffers(window); glfwPollEvents(); } virtual ~Font() { glDeleteBuffers(1, &vao); glDeleteBuffers(1, &vbo); glDeleteBuffers(1, &tex); FT_Done_Face(face); delete[] font_buff; } static int Int_max(int x, int y) { if (x < y) { return y; } else { return x; } } static int Char16_Length(const char16_t *text) { size_t size = sizeof(text) / sizeof(text); size_t length = size; char16_t c = 0; for (int i = 0; i < size; ++i) { c = text[i]; if ((c > 0xD800) && (0xDC00 > c)) { --length; } } return length; } };
あなたの回答
tips
プレビュー
