最初コミット

README.md

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+# Odinで書いたOpenGLレンダー
+
+記事：
+* [日本語](https://technicalsuwako.moe/blog/odin-review)
+* [English](https://technicalsuwako.moe/enblog/odin-review)
+
+![](https://ass.technicalsuwako.moe/2026-03-04-031210_scrot.png)

main.odin

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+package main
+
+import gl "vendor:OpenGL"
+import "vendor:glfw"
+import "core:fmt"
+import "core:os"
+import "core:c"
+
+framebuffer_cb :: proc "c" (window: glfw.WindowHandle, width: i32, height: i32) {
+  gl.Viewport(0, 0, width, height)
+}
+
+vertexSrc: cstring =
+`#version 330 core
+layout (location = 0) in vec3 aPos;
+void main() {
+  gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);
+}`
+
+fragSrc: cstring =
+`#version 330 core
+out vec4 FragColor;
+void main() {
+  FragColor = vec4(1.f, .5f, .2f, 1.f);
+}`
+
+WIDTH :: 500
+HEIGHT :: 300
+
+main ::proc() {
+  glfw.Init()
+  glfw.WindowHint(glfw.CONTEXT_VERSION_MAJOR, 3)
+  glfw.WindowHint(glfw.CONTEXT_VERSION_MINOR, 3)
+  glfw.WindowHint(glfw.OPENGL_PROFILE, glfw.OPENGL_CORE_PROFILE)
+
+  window := glfw.CreateWindow(WIDTH, HEIGHT, "例え", nil, nil)
+  defer glfw.Terminate()
+  if window == nil {
+    fmt.println("GLFWウィンドウを開くに失敗")
+    os.exit(-1)
+  }
+  glfw.MakeContextCurrent(window)
+
+  gl.load_up_to(3, 3, glfw.gl_set_proc_address)
+  gl.Viewport(0, 0, WIDTH, HEIGHT)
+  glfw.SetFramebufferSizeCallback(window, framebuffer_cb)
+
+  success: i32
+  infoLog: [512]c.char
+
+  vertexShader := gl.CreateShader(gl.VERTEX_SHADER)
+  gl.ShaderSource(vertexShader, 1, &vertexSrc, nil)
+  gl.CompileShader(vertexShader)
+
+  gl.GetShaderiv(vertexShader, gl.COMPILE_STATUS, &success)
+  if success != 1 {
+    gl.GetShaderInfoLog(vertexShader, 512, nil, raw_data(&infoLog))
+    os.exit(-1)
+  }
+
+  fragShader := gl.CreateShader(gl.FRAGMENT_SHADER)
+  gl.ShaderSource(fragShader, 1, &fragSrc, nil)
+  gl.CompileShader(fragShader)
+
+  gl.GetShaderiv(fragShader, gl.COMPILE_STATUS, &success)
+  if success != 1 {
+    gl.GetShaderInfoLog(fragShader, 512, nil, raw_data(&infoLog))
+    os.exit(-1)
+  }
+
+  shaderProgram := gl.CreateProgram()
+  defer gl.DeleteProgram(shaderProgram)
+  gl.AttachShader(shaderProgram, vertexShader)
+  gl.AttachShader(shaderProgram, fragShader)
+  gl.LinkProgram(shaderProgram)
+
+  gl.GetProgramiv(fragShader, gl.LINK_STATUS, &success)
+  if success != 1 {
+    gl.GetShaderInfoLog(fragShader, 512, nil, raw_data(&infoLog))
+    os.exit(-1)
+  }
+
+  gl.DeleteShader(vertexShader)
+  gl.DeleteShader(fragShader)
+
+  vertices := [?]f32 {
+     .5,  .5, .0,
+     .5, -.5, .0,
+    -.5, -.5, .0,
+    -.5,  .5, .0,
+  }
+
+  indices := [?]u32 {
+    0, 1, 3,
+    1, 2, 3,
+  }
+
+  VBO, VAO, EBO: u32
+  gl.GenVertexArrays(1, &VAO)
+  defer gl.DeleteVertexArrays(1, &VAO)
+  gl.GenBuffers(1, &VBO)
+  defer gl.DeleteBuffers(1, &VBO)
+  gl.GenBuffers(1, &EBO)
+  defer gl.DeleteBuffers(1, &EBO)
+  gl.BindVertexArray(VAO)
+
+  gl.BindBuffer(gl.ARRAY_BUFFER, VBO)
+  gl.BufferData(gl.ARRAY_BUFFER, size_of(vertices),
+                raw_data(&vertices), gl.STATIC_DRAW)
+
+  gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, EBO)
+  gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, size_of(indices),
+                raw_data(&indices), gl.STATIC_DRAW)
+
+  gl.VertexAttribPointer(0, 3, gl.FLOAT, gl.FALSE, 3 * size_of(f32), 0)
+  gl.EnableVertexAttribArray(0)
+
+  gl.BindBuffer(gl.ARRAY_BUFFER, 0)
+  gl.BindVertexArray(0)
+
+  for !glfw.WindowShouldClose(window) {
+    if glfw.GetKey(window, glfw.KEY_Q) == glfw.PRESS {
+      glfw.SetWindowShouldClose(window, true)
+    }
+
+    gl.ClearColor(.6, .1, .6, 1.)
+    gl.Clear(gl.COLOR_BUFFER_BIT)
+    gl.UseProgram(shaderProgram)
+    gl.BindVertexArray(VAO)
+    gl.DrawElements(gl.TRIANGLES, 6, gl.UNSIGNED_INT, nil)
+
+    glfw.SwapBuffers(window)
+    glfw.PollEvents()
+  }
+}