1 files changed, 124 insertions, 0 deletions
diff --git a/src/text.cpp b/src/text.cpp
new file mode 100644
index 0000000..8726b88
--- /dev/null
+++ b/src/text.cpp
@@ -0,0 +1,124 @@
+#include "text.hpp"
+
+#include <iostream>
+
+void TextSystem::configure([[maybe_unused]] entityx::EntityManager& entities,
+                           [[maybe_unused]] entityx::EventManager& events)
+{
+    if (FT_Init_FreeType(&freetype) != 0) {
+        // TODO handle error
+    }
+}
+    
+/**
+ * Draws the text for all entities.
+ */
+void TextSystem::update([[maybe_unused]] entityx::EntityManager& entites,
+                        [[maybe_unused]] entityx::EventManager& events,
+                        [[maybe_unused]] entityx::TimeDelta dt)
+{
+    // TODO render each Text component's text
+}
+
+void TextSystem::loadFont(const std::string& name,
+                          const std::string& file,
+                          int size)
+{
+    // Find or load font at given size
+    //
+
+    if (fonts.find(file) == fonts.end()) {
+        FT_Face face;
+        if (FT_New_Face(freetype, file.c_str(), 0, &face)) {
+            // TODO handle this error
+        }
+        fonts.emplace(file, face);
+    }
+
+    auto& face = fonts[file];
+    FT_Set_Pixel_Sizes(face, 0, size);
+    fontData.try_emplace(name);
+
+    // Calculate dimensions of final texture
+    //
+
+    float width = 0, height = 0;
+    for (int c = 32; c < 128; c++) {
+        FT_Load_Char(face, c, FT_LOAD_RENDER);
+        width += face->glyph->bitmap.width + 1;
+        height = std::max(height, static_cast<float>(face->glyph->bitmap.rows));
+    }
+
+    // Generate texture to hold entire font
+    //
+
+    auto& font = fontData[name];
+    glGenTextures(1, &font.tex);
+    glGenBuffers(1, &font.vbo);
+    glBindTexture(GL_TEXTURE_2D, font.tex);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width, height,
+                 0, GL_RED, GL_UNSIGNED_BYTE, 0);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+
+    //    // convert red-on-black to RGBA
+    //    auto& g = face->glyph;
+    //    std::vector<uint32_t> buf (g->bitmap.width * g->bitmap.rows, 0xFFFFFF);
+    //    for (auto j = buf.size(); j--;)
+    //        buf[j] |= g->bitmap.buffer[j] << 24;
+
+    // Load each character and add it to the texture
+    //
+
+    float offsetX = 0, offsetY = 0;
+    for (int c = 32; c < 128; c++) {
+        FT_Load_Char(face, c, FT_LOAD_RENDER);
+
+        auto* g = face->glyph;
+        glTexSubImage2D(GL_TEXTURE_2D, 0, offsetX, offsetY,
+                        g->bitmap.width, g->bitmap.rows,
+                        GL_RED, GL_UNSIGNED_BYTE,
+                        g->bitmap.buffer);
+
+        auto& d = font.data[c - 32];
+        d.dim = { g->bitmap.width, g->bitmap.rows };
+        d.bitmap = { g->bitmap_left, g->bitmap_top };
+        d.advance = { g->advance.x >> 6, g->advance.y >> 6 };
+
+        d.offset = { offsetX / width, offsetY / height };
+        offsetX += g->bitmap.width;
+        // Keep offsetY at zero?
+    }
+
+    std::cout << "Loaded font: " << file << " (size: " << size << ", tex: "
+              << font.tex << ")" << std::endl;
+}
+
+void TextSystem::updateVBOs(void)
+{
+    for (auto& data : fontData) {
+        auto& d = data.second;
+        d.buffer.clear();
+        for (auto& text : d.text) {
+            for (char c : text.text) {
+                if (c < 32)
+                    continue;
+
+                d.buffer += {
+                    text.x, text.y, text.z,
+                    d.data[c].offset.first, d.data[c].offset.second,
+                    1.0f
+                };
+            }
+        }
+
+        glBindBuffer(GL_ARRAY_BUFFER, d.vbo);
+        glBufferData(GL_ARRAY_BUFFER,
+                     d.text.size() * sizeof(TextMeshData), d.text.data(),
+                     GL_STREAM_DRAW);
+    }
+}
+