First working animations, but lots of bugs and refactoring needed.

45-animation/src/text.cpp

@@ -0,0 +1,114 @@
+#include "text.hpp"
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include "config.hpp"
+#include <ft2build.h>
+#include FT_FREETYPE_H
+
+void Text::render(const std::string& text, float x, float y, float scale, glm::vec3 color) {
+  text_shader.use();
+  glm::mat4 projection = glm::ortho(0.0f, static_cast<float>(SCR_WIDTH), 0.0f, static_cast<float>(SCR_HEIGHT));
+  text_shader.setMat4("projection", projection);
+
+  glUniform3f(glGetUniformLocation(text_shader.ID, "textColor"), color.x, color.y, color.z);
+  glActiveTexture(GL_TEXTURE0);
+  glBindVertexArray(text_vao);
+
+  for(auto c : text) {
+    auto& ch = characters.at(c);
+    float xpos = x + ch.bearing.x * scale;
+    float ypos = y - (ch.size.y - ch.bearing.y) * scale;
+    float w = ch.size.x * scale;
+    float h = ch.size.y * scale;
+
+    float vertices[6][4] = {
+      { xpos,     ypos + h,   0.0f, 0.0f },
+      { xpos,     ypos,       0.0f, 1.0f },
+      { xpos + w, ypos,       1.0f, 1.0f },
+
+      { xpos,     ypos + h,   0.0f, 0.0f },
+      { xpos + w, ypos,       1.0f, 1.0f },
+      { xpos + w, ypos + h,   1.0f, 0.0f }
+    };
+
+    // rander glyph texture over quad
+    glBindTexture(GL_TEXTURE_2D, ch.texture_id);
+
+    // update content of VBO memory
+    glBindBuffer(GL_ARRAY_BUFFER, text_vbo);
+    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices);
+
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    // render quad
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+
+    x += (ch.advance >> 6) * scale;
+  }
+
+  glBindVertexArray(0);
+  glBindTexture(GL_TEXTURE_2D, 0);
+}
+
+void Text::load_font() {
+  FT_Library ft;
+  int fail = FT_Init_FreeType(&ft);
+  dbc::check(fail == 0, "FreeType failed.");
+
+  FT_Face face;
+  fail = FT_New_Face(ft, font.c_str(), 0, &face);
+  dbc::check(fail == 0, "Failed to load font.");
+
+  // load the font bitmaps
+  FT_Set_Pixel_Sizes(face, 0, 48);
+  glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+
+  for(unsigned char c = 0; c < 255; c++) {
+    fail = FT_Load_Char(face, c, FT_LOAD_RENDER);
+    dbc::check(fail == 0, $F("Failed to load char {}", int(c)));
+
+    unsigned int texture = UINT_MAX;
+    glGenTextures(1, &texture);
+    glBindTexture(GL_TEXTURE_2D, texture);
+    glTexImage2D(
+        GL_TEXTURE_2D,
+        0,
+        GL_RED,
+        face->glyph->bitmap.width,
+        face->glyph->bitmap.rows,
+        0,
+        GL_RED,
+        GL_UNSIGNED_BYTE,
+        face->glyph->bitmap.buffer);
+
+    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);
+
+    characters.try_emplace(c,
+        texture,
+        glm::ivec2(face->glyph->bitmap.width, face->glyph->bitmap.rows),
+        glm::ivec2(face->glyph->bitmap_left, face->glyph->bitmap_top),
+        static_cast<unsigned int>(face->glyph->advance.x));
+  }
+
+  // unbind
+  glBindTexture(GL_TEXTURE_2D, 0);
+
+  // cleanup
+  FT_Done_Face(face);
+  FT_Done_FreeType(ft);
+
+  // create teh vao/vbo
+  glGenVertexArrays(1, &text_vao);
+  glGenBuffers(1, &text_vbo);
+  glBindVertexArray(text_vao);
+  glBindBuffer(GL_ARRAY_BUFFER, text_vbo);
+  glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 6 * 4, NULL, GL_DYNAMIC_DRAW);
+  glEnableVertexAttribArray(0);
+  glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 4 * sizeof(float), 0);
+  glBindVertexArray(0);
+}