gl01/main.go
2022-01-20 21:58:50 +08:00

131 lines
3.1 KiB
Go

package main
import (
"bytes"
"fmt"
"runtime"
"time"
"github.com/go-gl/gl/v4.1-core/gl"
"github.com/go-gl/glfw/v3.3/glfw"
"github.com/go-gl/mathgl/mgl32"
)
const (
windowWidth = 800
windowHeight = 600
)
func init() {
runtime.LockOSThread()
}
func main() {
if err := glfw.Init(); err != nil {
panic(err)
}
defer glfw.Terminate()
glfw.WindowHint(glfw.Resizable, 0)
glfw.WindowHint(glfw.ContextVersionMajor, 4)
glfw.WindowHint(glfw.ContextVersionMinor, 1)
glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
glfw.WindowHint(glfw.OpenGLForwardCompatible, 1)
win, err := glfw.CreateWindow(windowWidth, windowHeight, "Cube", nil, nil)
if err != nil {
panic(err)
}
win.MakeContextCurrent()
glfw.SwapInterval(1)
err = gl.Init()
if err != nil {
panic(err)
}
fmt.Println("OpenGL Version: ", gl.GoStr(gl.GetString(gl.VERSION)))
program, err := newProgram(shaderVert, shaderFrag)
if err != nil {
panic(err)
}
gl.UseProgram(program)
model := mgl32.Ident4()
modelUniform := gl.GetUniformLocation(program, gl.Str("model\x00"))
gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])
view := mgl32.LookAtV(mgl32.Vec3{3, 3, 3}, mgl32.Vec3{0, 0, 0}, mgl32.Vec3{0, 1, 0})
viewUniform := gl.GetUniformLocation(program, gl.Str("view\x00"))
gl.UniformMatrix4fv(viewUniform, 1, false, &view[0])
projection := mgl32.Perspective(mgl32.DegToRad(45), float32(windowWidth)/float32(windowHeight), 0.1, 10)
projectionUniform := gl.GetUniformLocation(program, gl.Str("projection\x00"))
gl.UniformMatrix4fv(projectionUniform, 1, false, &projection[0])
// Texture
textureUniform := gl.GetUniformLocation(program, gl.Str("tex\x00"))
gl.Uniform1i(textureUniform, 0)
texture, err := newTexture(bytes.NewReader(textureData))
if err != nil {
panic(err)
}
gl.BindFragDataLocation(program, 0, gl.Str("outputColor\x00"))
// Vertex Array
var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
// Vertex Buffer
var vbo uint32
gl.GenBuffers(1, &vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(cubeVertices)*4, gl.Ptr(cubeVertices), gl.STATIC_DRAW)
vertAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 5*4, gl.PtrOffset(0))
texCoordAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vertTexCoord\x00")))
gl.EnableVertexAttribArray(texCoordAttrib)
gl.VertexAttribPointer(texCoordAttrib, 2, gl.FLOAT, false, 5*4, gl.PtrOffset(3*4))
gl.Enable(gl.CULL_FACE)
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(1, 1, 1, 1)
angle := 0.0
prevTime := time.Now()
for !win.ShouldClose() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
// Angle update
angle += time.Since(prevTime).Seconds()
prevTime = time.Now()
model = mgl32.HomogRotate3D(float32(angle), mgl32.Vec3{0, 1, 0})
// Render
// Shader variable
gl.UseProgram(program)
gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])
gl.BindVertexArray(vao)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, texture)
gl.DrawArrays(gl.TRIANGLES, 0, 6*2*3)
win.SwapBuffers()
glfw.PollEvents()
}
}