それでは始めましょう。
ここで最初に書きたいのは、本から書き出したシェーダーです。 複数の三角形に2次元のテクスチャを適用します。
シェーダーを作成するために、別のクラスがあります。 私は彼にどのシェーダーをコンパイルするかを書いて、彼は私にプログラムを返します。 彼はまた、プログラムを名前でstd :: mapコンテナーに追加し、コードの別のセクションでこの特定のシェーダーのプログラムを取得できるようにします。
GLuint ShaderManager::createProgram ( const char *param ) { if ( !strncmp ( param, "sprite\0",7 ) ) { const char *vshader = "#version 300 es\n" "layout(location = 0) in vec2 position;\n" "layout(location = 1) in vec2 texCoord;\n" "uniform mat4 transform;\n" "out vec2 v_texCoord;\n" "void main ( )\n" "{\n" " gl_Position = transform * vec4 ( position, 0.0, 1.0 );\n" " v_texCoord = texCoord;\n" "}"; const char *fshader = "#version 300 es\n" "precision mediump float;\n" "in vec2 v_texCoord;\n" "layout(location = 0) out vec4 outColor;\n" "uniform sampler2D s_texture;\n" "void main ( )\n" "{\n" " outColor = texture ( s_texture, v_texCoord );\n" "}"; /* */ GLuint program = loadProgram ( vshader, fshader ); /* */ global.programs["sprite"] = program; return program;
次に、フォントクラスを作成しました。 このクラスのオブジェクトは、テキストを初期化し、画面上の位置を示し、テクスチャを描画します。
#ifndef H_FONT_H #define H_FONT_H #include <stdint.h> #include <ft2build.h> #include <string> #include <vector> #include <SDL2/SDL_opengl.h> #include <SDL2/SDL_opengles2.h> #include "gl_mat.hpp" #include "global.hpp" #include <wchar.h> #include FT_FREETYPE_H #include FT_GLYPH_H class Font { public: Font ( ) { } /* freetype ttf . */ Font ( const char *ttf_file ); /* */ void setPos ( int x, int y ); /* . *\1 . *\2 . *\3 . *\4 . *\5 . *\6 . *\7 . *\8 . * */ void init ( wchar_t *text, int fontSize, int align, int valign, int space, uint8_t r, uint8_t g, uint8_t b ); /* */ void setSize ( int w, int h ); /* */ void draw ( ); private: FT_Face face = 0; /* */ float *texture; /* */ float *vertices; /* : */ int width; /* : */ int height; /* */ int sampler; /* id */ GLuint textureid; /* x */ int x; /* y */ int y; /* glOrtho */ float ortho[4][4]; /* */ float translate[4][4]; /* */ float result[4][4]; /* */ unsigned int program; FT_Library ft_library; FT_Face ttf; }; #endif
さて、クラスの準備は完了です。 それでは始めましょう。 私はAndroid上でsdl2を使用してゲームを作成し、PC上でテストしています。 したがって、私はgles2とopenglを使用して画面にデータを表示する1つの方法を知っています。
それでは始めましょう。
#include "font.hpp" Font::Font ( const char *ttf_file ) { /* * android, cpp glm. * , * */ glm::clearMatrix4x4 ( &ortho[0] ); glm::clearMatrix4x4 ( &translate[0] ); glm::clearMatrix4x4 ( &result[0] ); /* */ program = global.programs["sprite"]; /* , */ int width = global.width; int height = global.height; /* , * 2d */ glm::ortho ( &ortho[0], 0.0f, width, 0.0f, height, 0.0f, 1.0f ); /* */ setPos ( 0, 0 ); /* freetype2. */ FT_Init_FreeType( &ft_library ); /* */ #ifdef __ANDROID__ FT_NewFace ( ft_library, ttf_file, 0, &face ); #else char *path = (char *) new char[255]; sprintf ( path, "assets/%s", ttf_file ); FT_New_Face ( ft_library, path, 0, &face ); delete[] path; #endif } /* */ void Font::init ( wchar_t *es, int fontSize, int align, int vert, int space, uint8_t r, uint8_t g, uint8_t b ) { /* */ FT_Set_Pixel_Sizes ( face, 0, fontSize ); FT_Glyph glyph; int w = 0; unsigned int h = 0; unsigned int maxh = 0; unsigned int toprow = 0; /* , * i, . */ int len = wcslen ( es ); /* , * . . * */ for ( int i = 0; i < len; i++ ) { /* */ wchar_t charcode = es[i]; /* bitmap */ FT_Load_Char ( face, charcode, FT_LOAD_RENDER ); FT_UInt glyph_index = FT_Get_Char_Index ( face, charcode ) FT_Load_Glyph ( face, glyph_index, FT_LOAD_DEFAULT ); FT_Render_Glyph ( face->glyph, FT_RENDER_MODE_NORMAL ); FT_Get_Glyph ( face->glyph, &glyph ); FT_Glyph_To_Bitmap ( &glyph, FT_RENDER_MODE_NORMAL, 0, 1 ); FT_BitmapGlyph bitmap_glyph = (FT_BitmapGlyph) glyph; FT_Bitmap bitmap = bitmap_glyph->bitmap; /* */ w += bitmap.width; /* . */ int resize = bitmap.rows > bitmap_glyph->top ? bitmap.rows - bitmap_glyph->top : bitmap_glyph->top - bitmap.rows; /* */ if ( h < bitmap.rows + resize ) h = bitmap.rows + resize; /* */ if ( toprow < bitmap.rows ) toprow = bitmap.rows; if ( maxh < bitmap.rows + bitmap_glyph->top ) maxh = bitmap.rows + bitmap_glyph->top; /* , w , * */ if ( charcode == ' ' ) w += space; /* ' ' * */ if ( charcode == '\n' ) { h += vert + maxh; FT_Done_Glyph ( glyph ); continue; } /* , align , */ w += align; FT_Done_Glyph ( glyph ); } /* , * */ if ( h <= 0 ) h = maxh; uint8_t im[h][w]; /* */ memset ( &im[0][0], 0, w * h * sizeof ( uint8_t ) ); int ih = 0; int iw = 0; int posy = 0; int topy = 0; int maxwidth = 0; for ( int i = 0; i < len; i++ ) { wchar_t charcode = es[i]; FT_Load_Char ( face, charcode, FT_LOAD_RENDER ); FT_UInt glyph_index = FT_Get_Char_Index ( face, charcode ); FT_Load_Glyph ( face, glyph_index, FT_LOAD_DEFAULT ); FT_Render_Glyph ( face->glyph, FT_RENDER_MODE_NORMAL ); FT_Get_Glyph ( face->glyph, &glyph ); FT_Glyph_To_Bitmap ( &glyph, FT_RENDER_MODE_NORMAL, 0, 1 ); FT_BitmapGlyph bitmap_glyph = (FT_BitmapGlyph) glyph; FT_Bitmap bitmap = bitmap_glyph->bitmap; /* */ posy = bitmap_glyph->top; /* , */ posy = bitmap.rows - posy; topy = toprow - bitmap.rows; /* , ih - , , * */ if ( charcode == '\n' ) { ih += maxh; iw = 0; FT_Done_Glyph ( glyph ); continue; } for ( unsigned int y = 0, i = 0; y < bitmap.rows; y++ ) { for ( unsigned int x = 0; x < bitmap.width; x++, i++ ) { if ( ( ih + posy + y + topy ) > h ) { if ( posy < 0 ) posy = abs ( posy ); } /* * gray, */ im [ ih + posy + y + topy ] [ iw + x ] = bitmap.buffer[i]; } } /* */ iw += bitmap.width; /* */ iw += align; if ( maxwidth < iw ) maxwidth = iw; if ( charcode == ' ' ) { iw += space; } FT_Done_Glyph ( glyph ); } iw = maxwidth; width = iw; height = h; unsigned int size = width * height; /* */ uint8_t *image_data = new uint8_t [ size * 4 ]; /* */ memset ( image_data, 255, size * 4 * sizeof ( uint8_t ) ); for ( unsigned int i = 0, y = 0; i < size; y++ ) { for ( int x = 0; x < width; x++, i++ ) { /* */ image_data[ 4 * i + 3] = im [ y ][ x ]; /* */ image_data[ 4 * i + 0] = r; image_data[ 4 * i + 1] = g; image_data[ 4 * i + 2] = b; } } /* */ glGenTextures ( 1, &textureid ); glBindTexture ( GL_TEXTURE_2D, textureid ); glTexImage2D ( GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, image_data ); 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); /* */ setSize ( width, height ); /* , image_data . */ delete[] image_data; } void Font::setSize ( int w, int h ) { /* , , */ if ( vertices ) delete[] vertices; if ( texture ) delete[] texture; vertices = new float [ 12 ]; vertices[0] = 0; vertices[1] = 0; vertices[2] = 0; vertices[3] = h; vertices[4] = w; vertices[5] = 0; vertices[6] = w; vertices[7] = 0; vertices[8] = w; vertices[9] = h; vertices[10] = 0; vertices[11] = h; /* , * */ texture = new float [ 12 ]; texture[0] = 0; texture[1] = 1; texture[2] = 0; texture[3] = 0; texture[4] = 1; texture[5] = 1; texture[6] = 1; texture[7] = 1; texture[8] = 1; texture[9] = 0; texture[10] = 0; texture[11] = 0; } void Font::setPos ( int x, int y ) { /* , */ this->x = x; this->y = y; glm::translate ( &translate[0], x, y, 0 ); glm::sumMatrix ( &result[0], &translate[0], &ortho[0] ); } void Font::draw ( ) { /* */ glUseProgram ( program ); sampler = glGetUniformLocation ( program, "s_texture" ); glActiveTexture ( GL_TEXTURE0 ); glBindTexture ( GL_TEXTURE_2D, textureid ); glUniform1i ( sampler, 0 ); GLint projection_location = glGetUniformLocation ( program, "transform" ); glUniformMatrix4fv ( projection_location, 1, GL_FALSE, &result[0][0] ); glEnableVertexAttribArray ( 0 ); glEnableVertexAttribArray ( 1 ); /* */ glVertexAttribPointer ( 0, 2, GL_FLOAT, GL_FALSE, 0, vertices ); /* */ glVertexAttribPointer ( 1, 2, GL_FLOAT, GL_FALSE, 0, texture ); /* */ glDrawArrays ( GL_TRIANGLES, 0, 12 ); glDisableVertexAttribArray ( 0 ); glDisableVertexAttribArray ( 1 ); }
コードから、この関数を次のように呼び出すことができます。
Font *font = new Font ("anonymous.ttf"); wchar_t * text = L" habr. . freetype opengl.\n" " freetype .\n" " , "; font->init ( text, 21, 1, 4, 4, 0, 0, 0 ); font->setPos ( 100, 100 );
