refactor font code into classes

engine/app.cpp

@@ -107,35 +107,12 @@ void App::init()
         printf("error loading image\n");
 
 #if _WIN32
-    FILE* font_file = fopen("C:\\Windows\\Fonts\\arial.ttf", "rb");
+    const char* ttf = "C:\\Windows\\Fonts\\arial.ttf";
 #else
-    FILE* font_file = fopen("/Library/Fonts/Arial.ttf", "rb");
+    const char* ttf = "/Library/Fonts/Arial.ttf";
 #endif
-    if (font_file)
+    FontManager::load(kFont::Arial_11, ttf);
-    {
+    text.create();
-        fseek(font_file, 0, SEEK_END);
-        long sz = ftell(font_file);
-        auto data = std::make_unique<uint8_t[]>(sz);
-        fseek(font_file, 0, SEEK_SET);
-        auto bytes = fread(data.get(), 1, sz, font_file);
-        assert(bytes==sz);
-        auto bitmap = std::make_unique<uint8_t[]>(w*h);
-        chars.resize(num_chars);
-        int ret = stbtt_BakeFontBitmap(data.get(), 0, 50, bitmap.get(), w, h, start_char, num_chars, chars.data());
-        font_tex.create(w, h, GL_RED, bitmap.get());
-        
-        glGenBuffers(2, font_buffers);
-        glGenVertexArrays(1, &font_array);
-        
-        glBindVertexArray(font_array);
-        glEnableVertexAttribArray(0);
-        glEnableVertexAttribArray(1);
-        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, font_buffers[1]);
-        glBindBuffer(GL_ARRAY_BUFFER, font_buffers[0]);
-        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(glm::vec4), (GLvoid*)0);
-        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(glm::vec4), (GLvoid*)(sizeof(float)*2));
-        glBindVertexArray(0);
-    }
     plane.create<1>(400, 400);
     
     glEnable(GL_TEXTURE_2D);
@@ -172,7 +149,6 @@ void App::update(float dt)
         layout[main_id].update(width, height);
     }
 
-    /*
     glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
     glEnable(GL_SCISSOR_TEST);
     for (auto& n : layout[main_id])
@@ -185,48 +161,10 @@ void App::update(float dt)
         }
     }
     glDisable(GL_SCISSOR_TEST); 
-*/
+
     glm::mat4 proj = glm::ortho(0.f, width, height, 0.f, -1.f, 1.f);
     glm::mat4 tran = glm::translate(glm::vec3(200, 200, 0));
 
-
-    if (chars.size())
-    {
-        static char str[64];
-        static int counter = 0;
-        counter++;
-        sprintf(str, "frame %04d", counter);
-        const auto len = strlen(str);
-        float x = 0;
-        float y = 0;
-        std::vector<glm::vec4> v;
-        std::vector<GLushort> idx;
-        for (int i = 0; i < len; i++)
-        {
-            int c = str[i] - start_char;
-            stbtt_aligned_quad q;
-            stbtt_GetBakedQuad(chars.data(), w, h, c, &x, &y, &q, true);
-            auto n = v.size();
-            v.emplace_back(q.x0, q.y1, q.s0, q.t1);
-            v.emplace_back(q.x0, q.y0, q.s0, q.t0);
-            v.emplace_back(q.x1, q.y0, q.s1, q.t0);
-            v.emplace_back(q.x1, q.y1, q.s1, q.t1);
-            idx.push_back(n+0);
-            idx.push_back(n+1);
-            idx.push_back(n+2);
-            idx.push_back(n+0);
-            idx.push_back(n+2);
-            idx.push_back(n+3);
-        }
-        font_array_count = (int)idx.size();
-        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, font_buffers[1]);
-        glBufferData(GL_ELEMENT_ARRAY_BUFFER, idx.size() * sizeof(GLushort), idx.data(), GL_STATIC_DRAW);
-        glBindBuffer(GL_ARRAY_BUFFER, font_buffers[0]);
-        glBufferData(GL_ARRAY_BUFFER, v.size() * sizeof(glm::vec4), v.data(), GL_STATIC_DRAW);
-        glBindBuffer(GL_ARRAY_BUFFER, 0);
-        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
-    }
-
     glActiveTexture(GL_TEXTURE0);
     font_tex.bind();
     sampler.bind(0);

engine/app.h

@@ -4,23 +4,16 @@
 #include "shape.h"
 #include "texture.h"
 #include "layout.h"
+#include "font.h"
 
 class App
 {
     Sampler sampler;
     Texture2D tex;
     LayoutManager layout;
-    stbtt_fontinfo font;
-    Texture2D font_tex;
-    std::vector<stbtt_bakedchar> chars;
     Plane plane;
-    GLuint font_array;
+    Font font;
-    int font_array_count = 0;
+    TextMesh text;
-    GLuint font_buffers[2];
-    const int w = 512;
-    const int h = 512;
-    const int num_chars = 96;
-    const int start_char = 32;
 public:
     static App I;
     float width;

engine/font.cpp

@@ -1,5 +1,92 @@
 #include "pch.h"
 #include "font.h"
 
+std::map<kFont, Font> FontManager::m_fonts;
 
+bool Font::load(const char* ttf)
+{
+    FILE* font_file = fopen(ttf, "rb");
+    if (font_file)
+    {
+        fseek(font_file, 0, SEEK_END);
+        long sz = ftell(font_file);
+        auto data = std::make_unique<uint8_t[]>(sz);
+        fseek(font_file, 0, SEEK_SET);
+        auto bytes = fread(data.get(), 1, sz, font_file);
+        assert(bytes==sz);
+        auto bitmap = std::make_unique<uint8_t[]>(w*h);
+        chars.resize(num_chars);
+        int ret = stbtt_BakeFontBitmap(data.get(), 0, 50, bitmap.get(), w, h, start_char, num_chars, chars.data());
+        font_tex.create(w, h, GL_RED, bitmap.get());
+        fclose(font_file);
+        return true;
+    }
+    return false;
+}
 
+bool FontManager::load(kFont id, const char *ttf)
+{
+    return m_fonts[id].load(ttf);
+}
+
+const Font& FontManager::get(kFont id)
+{
+    return m_fonts[id];
+}
+
+bool TextMesh::create()
+{
+    glGenBuffers(2, font_buffers);
+    glGenVertexArrays(1, &font_array);
+    
+    glBindVertexArray(font_array);
+    glEnableVertexAttribArray(0);
+    glEnableVertexAttribArray(1);
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, font_buffers[1]);
+    glBindBuffer(GL_ARRAY_BUFFER, font_buffers[0]);
+    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(glm::vec4), (GLvoid*)0);
+    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(glm::vec4), (GLvoid*)(sizeof(float)*2));
+    glBindVertexArray(0);
+    return true;
+}
+
+void TextMesh::update(kFont id, const char* text)
+{
+    auto& f = FontManager::get(id);
+    if (f.chars.size())
+    {
+        static char str[64];
+        static int counter = 0;
+        counter++;
+        sprintf(str, "frame %04d", counter);
+        const auto len = strlen(str);
+        float x = 0;
+        float y = 0;
+        std::vector<glm::vec4> v;
+        std::vector<GLushort> idx;
+        for (int i = 0; i < len; i++)
+        {
+            int c = str[i] - f.start_char;
+            stbtt_aligned_quad q;
+            stbtt_GetBakedQuad((stbtt_bakedchar*)f.chars.data(), f.w, f.h, c, &x, &y, &q, true);
+            auto n = v.size();
+            v.emplace_back(q.x0, q.y1, q.s0, q.t1);
+            v.emplace_back(q.x0, q.y0, q.s0, q.t0);
+            v.emplace_back(q.x1, q.y0, q.s1, q.t0);
+            v.emplace_back(q.x1, q.y1, q.s1, q.t1);
+            idx.push_back(n+0);
+            idx.push_back(n+1);
+            idx.push_back(n+2);
+            idx.push_back(n+0);
+            idx.push_back(n+2);
+            idx.push_back(n+3);
+        }
+        font_array_count = (int)idx.size();
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, font_buffers[1]);
+        glBufferData(GL_ELEMENT_ARRAY_BUFFER, idx.size() * sizeof(GLushort), idx.data(), GL_STATIC_DRAW);
+        glBindBuffer(GL_ARRAY_BUFFER, font_buffers[0]);
+        glBufferData(GL_ARRAY_BUFFER, v.size() * sizeof(glm::vec4), v.data(), GL_STATIC_DRAW);
+        glBindBuffer(GL_ARRAY_BUFFER, 0);
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+    }
+}

engine/font.h

@@ -1,4 +1,40 @@
 #pragma once
+#include "texture.h"
+#include "util.h"
 
+enum class kFont : uint16_t
+{
+    Arial_11 = const_hash("arial-16"),
+};
 
+class Font
+{
+public:
+    const int w = 512;
+    const int h = 512;
+    const int num_chars = 96;
+    const int start_char = 32;
+    stbtt_fontinfo font;
+    Texture2D font_tex;
+    std::vector<stbtt_bakedchar> chars;
     
+    bool load(const char* ttf);
+};
+
+class FontManager
+{
+    static std::map<kFont, Font> m_fonts;
+public:
+    static bool load(kFont id, const char* ttf);
+    static const Font& get(kFont id);
+};
+
+class TextMesh
+{
+public:
+    GLuint font_array = 0;
+    int font_array_count = 0;
+    GLuint font_buffers[2] = {0, 0};
+    bool create();
+    void update(kFont id, const char* text);
+};

engine/shape.h

@@ -9,7 +9,6 @@ protected:
     GLvoid* ioff[2]{ 0 };
     struct vertex_t { glm::vec4 pos; glm::vec2 uvs; };
 public:
-//    att::AttrubutesMap attribs;
     bool create_buffers(GLvoid* idx, GLvoid* vertices, int isize, int vsize);
     void draw_fill() const;
     void draw_stroke() const;