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开始折腾OpenGL

生命在于折腾啊。生命不息，折腾不止。

嗯，准备写一个类似Mineccraft的游戏

基本设定已经弄好了

不过目测是个大坑

希望到时候别弃坑吧

求有经验的人帮忙啊……

下面是go-gl的example源码

顺便测试一下代码高亮

  1. package main
  3. import (
  4.     "errors"
  5.     "fmt"
  6.     "github.com/go-gl/gl"
  7.     glfw "github.com/go-gl/glfw3"
  8.     "image"
  9.     "image/png"
  10.     "io"
  11.     "os"
  12. )
  14. const (
  15.     Title  = "Spinning Gopher"
  16.     Width  = 640
  17.     Height = 480
  18. )
  20. var (
  21.     texture    gl.Texture
  22.     rotx, roty float32
  23.     ambient    []float32 = []float32{0.5, 0.5, 0.5, 1}
  24.     diffuse    []float32 = []float32{1, 1, 1, 1}
  25.     lightpos   []float32 = []float32{-5, 5, 10, 0}
  26. )
  28. func errorCallback(err glfw.ErrorCode, desc string) {
  29.     fmt.Printf("%v: %v\n", err, desc)
  30. }
  32. func main() {
  33.     glfw.SetErrorCallback(errorCallback)
  35.     if !glfw.Init() {
  36.         panic("Can't init glfw!")
  37.     }
  38.     defer glfw.Terminate()
  40.     window, err := glfw.CreateWindow(Width, Height, Title, nil, nil)
  41.     if err != nil {
  42.         panic(err)
  43.     }
  45.     window.MakeContextCurrent()
  47.     glfw.SwapInterval(1)
  49.     gl.Init()
  51.     if err := initScene(); err != nil {
  52.         fmt.Fprintf(os.Stderr, "init: %s\n", err)
  53.         return
  54.     }
  55.     defer destroyScene()
  57.     for !window.ShouldClose() {
  58.         drawScene()
  59.         window.SwapBuffers()
  60.         glfw.PollEvents()
  61.     }
  62. }
  64. func createTexture(r io.Reader) (gl.Texture, error) {
  65.     img, err := png.Decode(r)
  66.     if err != nil {
  67.         return gl.Texture(0), err
  68.     }
  70.     rgbaImg, ok := img.(*image.NRGBA)
  71.     if !ok {
  72.         return gl.Texture(0), errors.New("texture must be an NRGBA image")
  73.     }
  75.     textureId := gl.GenTexture()
  76.     textureId.Bind(gl.TEXTURE_2D)
  77.     gl.TexParameterf(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
  78.     gl.TexParameterf(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
  80.     // flip image: first pixel is lower left corner
  81.     imgWidth, imgHeight := img.Bounds().Dx(), img.Bounds().Dy()
  82.     data := make([]byte, imgWidth*imgHeight*4)
  83.     lineLen := imgWidth * 4
  84.     dest := len(data) - lineLen
  85.     for src := 0; src < len(rgbaImg.Pix); src += rgbaImg.Stride {
  86.         copy(data[dest:dest+lineLen], rgbaImg.Pix[src:src+rgbaImg.Stride])
  87.         dest -= lineLen
  88.     }
  89.     gl.TexImage2D(gl.TEXTURE_2D, 0, 4, imgWidth, imgHeight, 0, gl.RGBA, gl.UNSIGNED_BYTE, data)
  91.     return textureId, nil
  92. }
  94. func initScene() (err error) {
  95.     gl.Enable(gl.TEXTURE_2D)
  96.     gl.Enable(gl.DEPTH_TEST)
  97.     gl.Enable(gl.LIGHTING)
  99.     gl.ClearColor(0.5, 0.5, 0.5, 0.0)
  100.     gl.ClearDepth(1)
  101.     gl.DepthFunc(gl.LEQUAL)
  103.     gl.Lightfv(gl.LIGHT0, gl.AMBIENT, ambient)
  104.     gl.Lightfv(gl.LIGHT0, gl.DIFFUSE, diffuse)
  105.     gl.Lightfv(gl.LIGHT0, gl.POSITION, lightpos)
  106.     gl.Enable(gl.LIGHT0)
  108.     gl.Viewport(0, 0, Width, Height)
  109.     gl.MatrixMode(gl.PROJECTION)
  110.     gl.LoadIdentity()
  111.     gl.Frustum(-1, 1, -1, 1, 1.0, 10.0)
  112.     gl.MatrixMode(gl.MODELVIEW)
  113.     gl.LoadIdentity()
  115.     goph, err := os.Open("gopher.png")
  116.     if err != nil {
  117.         panic(err)
  118.     }
  119.     defer goph.Close()
  121.     texture, err = createTexture(goph)
  122.     return
  123. }
  125. func destroyScene() {
  126.     texture.Delete()
  127. }
  129. func drawScene() {
  130.     gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
  132.     gl.MatrixMode(gl.MODELVIEW)
  133.     gl.LoadIdentity()
  134.     gl.Translatef(0, 0, -3.0)
  135.     gl.Rotatef(rotx, 1, 0, 0)
  136.     gl.Rotatef(roty, 0, 1, 0)
  138.     rotx += 0.5
  139.     roty += 0.1
  141.     texture.Bind(gl.TEXTURE_2D)
  143.     gl.Color4f(1, 1, 1, 1)
  145.     gl.Begin(gl.QUADS)
  147.     gl.Normal3f(0, 0, 1)
  148.     gl.TexCoord2f(0, 0)
  149.     gl.Vertex3f(-1, -1, 1)
  150.     gl.TexCoord2f(1, 0)
  151.     gl.Vertex3f(1, -1, 1)
  152.     gl.TexCoord2f(1, 1)
  153.     gl.Vertex3f(1, 1, 1)
  154.     gl.TexCoord2f(0, 1)
  155.     gl.Vertex3f(-1, 1, 1)
  157.     gl.Normal3f(0, 0, -1)
  158.     gl.TexCoord2f(1, 0)
  159.     gl.Vertex3f(-1, -1, -1)
  160.     gl.TexCoord2f(1, 1)
  161.     gl.Vertex3f(-1, 1, -1)
  162.     gl.TexCoord2f(0, 1)
  163.     gl.Vertex3f(1, 1, -1)
  164.     gl.TexCoord2f(0, 0)
  165.     gl.Vertex3f(1, -1, -1)
  167.     gl.Normal3f(0, 1, 0)
  168.     gl.TexCoord2f(0, 1)
  169.     gl.Vertex3f(-1, 1, -1)
  170.     gl.TexCoord2f(0, 0)
  171.     gl.Vertex3f(-1, 1, 1)
  172.     gl.TexCoord2f(1, 0)
  173.     gl.Vertex3f(1, 1, 1)
  174.     gl.TexCoord2f(1, 1)
  175.     gl.Vertex3f(1, 1, -1)
  177.     gl.Normal3f(0, -1, 0)
  178.     gl.TexCoord2f(1, 1)
  179.     gl.Vertex3f(-1, -1, -1)
  180.     gl.TexCoord2f(0, 1)
  181.     gl.Vertex3f(1, -1, -1)
  182.     gl.TexCoord2f(0, 0)
  183.     gl.Vertex3f(1, -1, 1)
  184.     gl.TexCoord2f(1, 0)
  185.     gl.Vertex3f(-1, -1, 1)
  187.     gl.Normal3f(1, 0, 0)
  188.     gl.TexCoord2f(1, 0)
  189.     gl.Vertex3f(1, -1, -1)
  190.     gl.TexCoord2f(1, 1)
  191.     gl.Vertex3f(1, 1, -1)
  192.     gl.TexCoord2f(0, 1)
  193.     gl.Vertex3f(1, 1, 1)
  194.     gl.TexCoord2f(0, 0)
  195.     gl.Vertex3f(1, -1, 1)
  197.     gl.Normal3f(-1, 0, 0)
  198.     gl.TexCoord2f(0, 0)
  199.     gl.Vertex3f(-1, -1, -1)
  200.     gl.TexCoord2f(1, 0)
  201.     gl.Vertex3f(-1, -1, 1)
  202.     gl.TexCoord2f(1, 1)
  203.     gl.Vertex3f(-1, 1, 1)
  204.     gl.TexCoord2f(0, 1)
  205.     gl.Vertex3f(-1, 1, -1)
  207.     gl.End()
  208. }