/
main.go
283 lines (238 loc) · 6.64 KB
/
main.go
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package main
import (
"fmt"
"time"
"github.com/go-gl/mathgl/mgl32"
"golang.org/x/mobile/app"
"golang.org/x/mobile/event/size"
"golang.org/x/mobile/event/lifecycle"
"golang.org/x/mobile/event/paint"
"golang.org/x/mobile/event/touch"
"golang.org/x/mobile/exp/app/debug"
"golang.org/x/mobile/geom"
"golang.org/x/mobile/gl"
"bytes"
"encoding/binary"
_ "image/png"
"io/ioutil"
"golang.org/x/mobile/asset"
"golang.org/x/mobile/exp/gl/glutil"
"golang.org/x/mobile/exp/f32"
)
type Shape struct {
buf gl.Buffer
colorbuf gl.Buffer
}
type Shader struct {
program gl.Program
vertCoord gl.Attrib
projection gl.Uniform
view gl.Uniform
modelx gl.Uniform
modely gl.Uniform
color gl.Attrib
}
type Engine struct {
shader Shader
shape Shape
touchLocX geom.Pt
touchLocY geom.Pt
started time.Time
}
func (e *Engine) Start() {
var err error
e.shader.program, err = LoadProgram("shader.v.glsl", "shader.f.glsl")
if err != nil {
panic(fmt.Sprintln("LoadProgram failed:", err))
}
e.shape.buf = gl.CreateBuffer()
gl.BindBuffer(gl.ARRAY_BUFFER, e.shape.buf)
gl.BufferData(gl.ARRAY_BUFFER, cubeData, gl.STATIC_DRAW)
fmt.Println(len(cubeData))
e.shader.vertCoord = gl.GetAttribLocation(e.shader.program, "vertCoord")
e.shader.projection = gl.GetUniformLocation(e.shader.program, "projection")
e.shader.view = gl.GetUniformLocation(e.shader.program, "view")
e.shader.modelx = gl.GetUniformLocation(e.shader.program, "modelx")
e.shader.modely = gl.GetUniformLocation(e.shader.program, "modely")
e.shader.color = gl.GetAttribLocation(e.shader.program, "color")
e.shape.colorbuf = gl.CreateBuffer()
gl.BindBuffer(gl.ARRAY_BUFFER, e.shape.colorbuf)
gl.BufferData(gl.ARRAY_BUFFER, colorData, gl.STATIC_DRAW)
gl.VertexAttribPointer(e.shader.color, colorsPerVertex, gl.FLOAT, false, 4, 0) //更新color值
gl.DrawArrays(gl.TRIANGLES, 0, vertexCount)
e.started = time.Now()
}
func (e *Engine) Stop() {
gl.DeleteProgram(e.shader.program)
gl.DeleteBuffer(e.shape.buf)
gl.DeleteBuffer(e.shape.colorbuf)
}
func (e *Engine) Draw(c size.Event) {
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(0, 0, 0, 1)
gl.Clear(gl.COLOR_BUFFER_BIT)
gl.Clear(gl.DEPTH_BUFFER_BIT)
gl.UseProgram(e.shader.program)
m := mgl32.Perspective(0.785, float32(c.WidthPt/c.HeightPt), 0.1, 10.0)
gl.UniformMatrix4fv(e.shader.projection, m[:])
eye := mgl32.Vec3{0, 3, 3}
center := mgl32.Vec3{0, 0, 0}
up := mgl32.Vec3{0, 1, 0}
m = mgl32.LookAtV(eye, center, up)
gl.UniformMatrix4fv(e.shader.view, m[:])
m = mgl32.HomogRotate3D(float32(e.touchLocX*5/c.WidthPt), mgl32.Vec3{0, 1, 0})
gl.UniformMatrix4fv(e.shader.modelx, m[:])
m = mgl32.HomogRotate3D(float32(e.touchLocY*5/c.HeightPt), mgl32.Vec3{1, 0, 0})
gl.UniformMatrix4fv(e.shader.modely, m[:])
gl.BindBuffer(gl.ARRAY_BUFFER, e.shape.buf)
gl.EnableVertexAttribArray(e.shader.vertCoord)
gl.VertexAttribPointer(e.shader.vertCoord, coordsPerVertex, gl.FLOAT, false, 0, 0)
gl.BindBuffer(gl.ARRAY_BUFFER, e.shape.colorbuf)
gl.EnableVertexAttribArray(e.shader.color)
gl.VertexAttribPointer(e.shader.color, colorsPerVertex, gl.FLOAT, false, 0, 0) //更新color值
gl.DrawArrays(gl.TRIANGLES, 0, vertexCount)
gl.DisableVertexAttribArray(e.shader.vertCoord)
gl.DisableVertexAttribArray(e.shader.color)
debug.DrawFPS(c)
}
var cubeData = f32.Bytes(binary.LittleEndian,
-1.0, -1.0, -1.0,
1.0, -1.0, -1.0,
-1.0, -1.0, 1.0,
1.0, -1.0, -1.0,
1.0, -1.0, 1.0,
-1.0, -1.0, 1.0,
-1.0, 1.0, -1.0,
-1.0, 1.0, 1.0,
1.0, 1.0, -1.0,
1.0, 1.0, -1.0,
-1.0, 1.0, 1.0,
1.0, 1.0, 1.0,
-1.0, -1.0, 1.0,
1.0, -1.0, 1.0,
-1.0, 1.0, 1.0,
1.0, -1.0, 1.0,
1.0, 1.0, 1.0,
-1.0, 1.0, 1.0,
-1.0, -1.0, -1.0,
-1.0, 1.0, -1.0,
1.0, -1.0, -1.0,
1.0, -1.0, -1.0,
-1.0, 1.0, -1.0,
1.0, 1.0, -1.0,
-1.0, -1.0, 1.0,
-1.0, 1.0, -1.0,
-1.0, -1.0, -1.0,
-1.0, -1.0, 1.0,
-1.0, 1.0, 1.0,
-1.0, 1.0, -1.0,
1.0, -1.0, 1.0,
1.0, -1.0, -1.0,
1.0, 1.0, -1.0,
1.0, -1.0, 1.0,
1.0, 1.0, -1.0,
1.0, 1.0, 1.0,
)
var colorData = f32.Bytes(binary.LittleEndian, //过渡色
1,1,1,1,
1,1,0,1,
1,0,1,1,
1,1,0,1,
0,1,0,1,
1,0,1,1,
0,0,0,1,
1,0,0,1,
0,0,1,1,
0,0,1,1,
1,0,0,1,
0,1,1,1,
1,0,1,1,
0,1,0,1,
1,0,0,1,
0,1,0,1,
0,1,1,1,
1,0,0,1,
1,1,1,1,
0,0,0,1,
1,1,0,1,
1,1,0,1,
0,0,0,1,
0,0,1,1,
1,0,1,1,
0,0,0,1,
1,1,1,1,
1,0,1,1,
1,0,0,1,
0,0,0,1,
0,1,0,1,
1,1,0,1,
0,0,1,1,
0,1,0,1,
0,0,1,1,
0,1,1,1,
)
const (
coordsPerVertex = 3 //坐标属性个数 x y z
vertexCount = 36 //总点数
colorsPerVertex = 4 //颜色属性个数 r g b a
)
func main() {
e := Engine{}
app.Main(func(a app.App) {
var c size.Event
for eve := range a.Events() {
switch eve := app.Filter(eve).(type) {
case lifecycle.Event:
switch eve.Crosses(lifecycle.StageVisible) {
case lifecycle.CrossOn:
e.Start()
case lifecycle.CrossOff:
e.Stop()
}
case size.Event:
c = eve
e.touchLocX = c.WidthPt / 2
e.touchLocY=c.HeightPt / 2
case paint.Event:
e.Draw(c)
a.EndPaint(eve)
case touch.Event:
e.touchLocX = geom.Pt(eve.X/c.PixelsPerPt)
e.touchLocY = geom.Pt(eve.Y/c.PixelsPerPt)
}
}
})
}
// EncodeObject converts float32 vertices into a LittleEndian byte array.
func EncodeObject(vertices ...[]float32) []byte {
buf := bytes.Buffer{}
for _, v := range vertices {
err := binary.Write(&buf, binary.LittleEndian, v)
if err != nil {
panic(fmt.Sprintln("binary.Write failed:", err))
}
}
return buf.Bytes()
}
func loadAsset(name string) ([]byte, error) {
f, err := asset.Open(name)
if err != nil {
return nil, err
}
return ioutil.ReadAll(f)
}
// LoadProgram reads shader sources from the asset repository, compiles, and
// links them into a program.
func LoadProgram(vertexAsset, fragmentAsset string) (p gl.Program, err error) {
vertexSrc, err := loadAsset(vertexAsset)
if err != nil {
return
}
fragmentSrc, err := loadAsset(fragmentAsset)
if err != nil {
return
}
p, err = glutil.CreateProgram(string(vertexSrc), string(fragmentSrc))
return
}