/* Freetype GL - A C OpenGL Freetype engine * * Distributed under the OSI-approved BSD 2-Clause License. See accompanying * file `LICENSE` for more details. */ #include #include #include "freetype-gl.h" #include "vertex-buffer.h" #include "text-buffer.h" #include "markup.h" #include "shader.h" #include "mat4.h" #include "screenshot-util.h" #include // ------------------------------------------------------- typedef & struct --- typedef struct { float x, y, z; // position float s, t; // texture float r, g, b, a; // color } vertex_t; typedef struct { float x, y, z; vec4 color; } point_t; // ------------------------------------------------------- global variables --- texture_atlas_t *atlas; vertex_buffer_t * text_buffer; vertex_buffer_t * line_buffer; vertex_buffer_t * point_buffer; GLuint shader, text_shader; mat4 model, view, projection; const int width = 600; const int height = 600; // --------------------------------------------------------------- add_text --- void add_text( vertex_buffer_t * buffer, texture_font_t * font, char *text, vec4 * color, vec2 * pen ) { size_t i; float r = color->red, g = color->green, b = color->blue, a = color->alpha; for( i = 0; i < strlen(text); ++i ) { texture_glyph_t *glyph = texture_font_get_glyph( font, text + i ); if( glyph != NULL ) { float kerning = 0.0f; if( i > 0) { kerning = texture_glyph_get_kerning( glyph, text + i - 1 ); } pen->x += kerning; int x0 = (int)( pen->x + glyph->offset_x ); int y0 = (int)( pen->y + glyph->offset_y ); int x1 = (int)( x0 + glyph->width ); int y1 = (int)( y0 - glyph->height ); float s0 = glyph->s0; float t0 = glyph->t0; float s1 = glyph->s1; float t1 = glyph->t1; GLuint indices[] = {0,1,2,0,2,3}; vertex_t vertices[] = { { x0,y0,0, s0,t0, r,g,b,a }, { x0,y1,0, s0,t1, r,g,b,a }, { x1,y1,0, s1,t1, r,g,b,a }, { x1,y0,0, s1,t0, r,g,b,a } }; vertex_buffer_push_back( buffer, vertices, 4, indices, 6 ); pen->x += glyph->advance_x; } } } // ------------------------------------------------------------------- init --- void init( void ) { vec4 blue = {{0,0,1,1}}; vec4 black = {{0,0,0,1}}; atlas = texture_atlas_new( 512, 512, 1 ); texture_font_t * big = texture_font_new_from_file( atlas, 400, "fonts/Vera.ttf"); texture_font_t * small = texture_font_new_from_file( atlas, 18, "fonts/Vera.ttf"); texture_font_t * title = texture_font_new_from_file( atlas, 32, "fonts/Vera.ttf"); text_buffer = vertex_buffer_new( "vertex:3f,tex_coord:2f,color:4f" ); line_buffer = vertex_buffer_new( "vertex:3f,color:4f" ); point_buffer = vertex_buffer_new( "vertex:3f,color:4f" ); vec2 pen, origin; texture_glyph_t *glyph = texture_font_get_glyph( big, "g" ); origin.x = width/2 - glyph->offset_x - glyph->width/2; origin.y = height/2 - glyph->offset_y + glyph->height/2; add_text( text_buffer, big, "g", &black, &origin ); // title pen.x = 50; pen.y = 560; add_text( text_buffer, title, "Glyph metrics", &black, &pen ); point_t vertices[] = { // Baseline {0.1*width, origin.y, 0, black}, {0.9*width, origin.y, 0, black}, // Top line {0.1*width, origin.y + glyph->offset_y, 0, black}, {0.9*width, origin.y + glyph->offset_y, 0, black}, // Bottom line {0.1*width, origin.y + glyph->offset_y - glyph->height, 0, black}, {0.9*width, origin.y + glyph->offset_y - glyph->height, 0, black}, // Left line at origin {width/2-glyph->offset_x-glyph->width/2, 0.1*height, 0, black}, {width/2-glyph->offset_x-glyph->width/2, 0.9*height, 0, black}, // Left line {width/2 - glyph->width/2, .3*height, 0, black}, {width/2 - glyph->width/2, .9*height, 0, black}, // Right line {width/2 + glyph->width/2, .3*height, 0, black}, {width/2 + glyph->width/2, .9*height, 0, black}, // Right line at origin {width/2-glyph->offset_x-glyph->width/2+glyph->advance_x, 0.1*height, 0, black}, {width/2-glyph->offset_x-glyph->width/2+glyph->advance_x, 0.7*height, 0, black}, // Width {width/2 - glyph->width/2, 0.8*height, 0, blue}, {width/2 + glyph->width/2, 0.8*height, 0, blue}, // Advance_x {width/2-glyph->width/2-glyph->offset_x, 0.2*height, 0, blue}, {width/2-glyph->width/2-glyph->offset_x+glyph->advance_x, 0.2*height, 0, blue}, // Offset_x {width/2-glyph->width/2-glyph->offset_x, 0.85*height, 0, blue}, {width/2-glyph->width/2, 0.85*height, 0, blue}, // Height {0.3*width/2, origin.y + glyph->offset_y - glyph->height, 0, blue}, {0.3*width/2, origin.y + glyph->offset_y, 0, blue}, // Offset y {0.8*width, origin.y + glyph->offset_y, 0, blue}, {0.8*width, origin.y , 0, blue}, }; GLuint indices [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12, 13,14,15,16,17,18,19,20,21,22,23,24,25}; vertex_buffer_push_back( line_buffer, vertices, 26, indices, 26 ); pen.x = width/2 - 48; pen.y = .2*height - 18; add_text( text_buffer, small, "advance_x", &blue, &pen ); pen.x = width/2 - 20; pen.y = .8*height + 3; add_text( text_buffer, small, "width", &blue, &pen ); pen.x = width/2 - glyph->width/2 + 5; pen.y = .85*height-8; add_text( text_buffer, small, "offset_x", &blue, &pen ); pen.x = 0.2*width/2-30; pen.y = origin.y + glyph->offset_y - glyph->height/2; add_text( text_buffer, small, "height", &blue, &pen ); pen.x = 0.8*width+3; pen.y = origin.y + glyph->offset_y/2 -6; add_text( text_buffer, small, "offset_y", &blue, &pen ); pen.x = width/2 - glyph->offset_x - glyph->width/2 - 58; pen.y = height/2 - glyph->offset_y + glyph->height/2 - 20; add_text( text_buffer, small, "Origin", &black, &pen ); glGenTextures( 1, &atlas->id ); glBindTexture( GL_TEXTURE_2D, atlas->id ); 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_MAG_FILTER, GL_LINEAR ); glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR ); glTexImage2D( GL_TEXTURE_2D, 0, GL_RED, atlas->width, atlas->height, 0, GL_RED, GL_UNSIGNED_BYTE, atlas->data ); GLuint i = 0; point_t p; p.color = black; // Origin point p.x = width/2 - glyph->offset_x - glyph->width/2; p.y = height/2 - glyph->offset_y + glyph->height/2; vertex_buffer_push_back( point_buffer, &p, 1, &i, 1 ); // Advance point p.x = width/2 - glyph->offset_x - glyph->width/2 + glyph->advance_x; p.y = height/2 - glyph->offset_y + glyph->height/2; vertex_buffer_push_back( point_buffer, &p, 1, &i, 1 ); text_shader = shader_load( "shaders/v3f-t2f-c4f.vert", "shaders/v3f-t2f-c4f.frag" ); shader = shader_load( "shaders/v3f-c4f.vert", "shaders/v3f-c4f.frag" ); mat4_set_identity( &projection ); mat4_set_identity( &model ); mat4_set_identity( &view ); } // ---------------------------------------------------------------- display --- void display( GLFWwindow* window ) { int viewport[4]; glGetIntegerv( GL_VIEWPORT, viewport ); glClearColor(1,1,1,1); glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); glEnable( GL_BLEND ); glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ); glEnable( GL_POINT_SMOOTH ); glEnable( GL_TEXTURE_2D ); glUseProgram( text_shader ); { glUniform1i( glGetUniformLocation( text_shader, "texture" ), 0 ); glUniformMatrix4fv( glGetUniformLocation( text_shader, "model" ), 1, 0, model.data); glUniformMatrix4fv( glGetUniformLocation( text_shader, "view" ), 1, 0, view.data); glUniformMatrix4fv( glGetUniformLocation( text_shader, "projection" ), 1, 0, projection.data); vertex_buffer_render( text_buffer, GL_TRIANGLES ); } glDisable( GL_TEXTURE_2D ); glPointSize( 10.0f ); glUseProgram( shader ); { glUniformMatrix4fv( glGetUniformLocation( shader, "model" ), 1, 0, model.data); glUniformMatrix4fv( glGetUniformLocation( shader, "view" ), 1, 0, view.data); glUniformMatrix4fv( glGetUniformLocation( shader, "projection" ), 1, 0, projection.data); vertex_buffer_render( line_buffer, GL_LINES ); vertex_buffer_render( point_buffer, GL_POINTS ); } glUseProgram( 0 ); glfwSwapBuffers( window ); } // ---------------------------------------------------------------- reshape --- void reshape( GLFWwindow* window, int width, int height ) { glViewport(0, 0, width, height); mat4_set_orthographic( &projection, 0, width, 0, height, -1, 1); } // --------------------------------------------------------------- keyboard --- void keyboard( GLFWwindow* window, int key, int scancode, int action, int mods ) { if ( key == GLFW_KEY_ESCAPE && action == GLFW_PRESS ) { glfwSetWindowShouldClose( window, GL_TRUE ); } } // --------------------------------------------------------- error-callback --- void error_callback( int error, const char* description ) { fputs( description, stderr ); } // ------------------------------------------------------------------- main --- int main( int argc, char **argv ) { GLFWwindow* window; char* screenshot_path = NULL; if (argc > 1) { if (argc == 3 && 0 == strcmp( "--screenshot", argv[1] )) screenshot_path = argv[2]; else { fprintf( stderr, "Unknown or incomplete parameters given\n" ); exit( EXIT_FAILURE ); } } glfwSetErrorCallback( error_callback ); if (!glfwInit( )) { exit( EXIT_FAILURE ); } glfwWindowHint( GLFW_VISIBLE, GL_FALSE ); glfwWindowHint( GLFW_RESIZABLE, GL_FALSE ); window = glfwCreateWindow( width, height, argv[0], NULL, NULL ); if (!window) { glfwTerminate( ); exit( EXIT_FAILURE ); } glfwMakeContextCurrent( window ); glfwSwapInterval( 1 ); glfwSetFramebufferSizeCallback( window, reshape ); glfwSetWindowRefreshCallback( window, display ); glfwSetKeyCallback( window, keyboard ); #ifndef __APPLE__ glewExperimental = GL_TRUE; GLenum err = glewInit(); if (GLEW_OK != err) { /* Problem: glewInit failed, something is seriously wrong. */ fprintf( stderr, "Error: %s\n", glewGetErrorString(err) ); exit( EXIT_FAILURE ); } fprintf( stderr, "Using GLEW %s\n", glewGetString(GLEW_VERSION) ); #endif init(); glfwShowWindow( window ); reshape( window, width, height ); while (!glfwWindowShouldClose( window )) { display( window ); glfwPollEvents( ); if (screenshot_path) { screenshot( window, screenshot_path ); glfwSetWindowShouldClose( window, 1 ); } } glDeleteTextures( 1, &atlas->id ); atlas->id = 0; texture_atlas_delete( atlas ); glfwDestroyWindow( window ); glfwTerminate( ); return EXIT_SUCCESS; }