Commit 6cc9f3a1 authored by Boris Mühmer's avatar Boris Mühmer
Browse files

imported and adapted gldemo

parent 9986b87f

main.go

+3 −2
Original line number Diff line number Diff line
@@ -6,7 +6,8 @@ import ( 


	"repositories.muehmer.net/bsmrgo/saola/support/scene"



	si "repositories.muehmer.net/bsmrgo/graphics-playground/scenes/icosahedron"

	//si "repositories.muehmer.net/bsmrgo/graphics-playground/scenes/icosahedron"

	sd "repositories.muehmer.net/bsmrgo/graphics-playground/scenes/gldemo"

)



func init() {
@@ -31,6 +32,6 @@ func main() { 
		ContextVersionMinor:    3,

		CenterOnPrimaryMonitor: true,

	}

	hooks := si.Hooks()

	hooks := sd.Hooks()

	scene.Manage(setup, hooks)

}

scenes/gldemo/gldemo.go

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+323 −0
Original line number Diff line number Diff line 
package gldemo



import (

	"fmt"

	"image"

	"image/draw"

	_ "image/png" // register PNG

	"log"

	"os"

	"strings"



	"github.com/go-gl/gl/v4.3-core/gl"

	"github.com/go-gl/glfw/v3.2/glfw"

	"github.com/go-gl/mathgl/mgl32"

	"repositories.muehmer.net/bsmrgo/saola/support/scene"

)



const (

	sceneName    = "GL-Demo"

	windowWidth  = 1650

	windowHeight = 1080

)



var (

	angle        float64

	previousTime float64

	err          error

	program      uint32

	projection   mgl32.Mat4

	camera       mgl32.Mat4

	model        mgl32.Mat4

	modelUniform int32

	texture      uint32

	vao          uint32

)



// Hooks returns our hooks.

func Hooks() scene.HooksType {

	hooks := scene.HooksType{

		Initialize: initialize,

		Render:     render,

		Resize:     resize,

		Key:        keyCallback,

	}

	return hooks

}



func initialize() {

	fmt.Fprintf(os.Stderr, "[%s] Initialize()\n", sceneName)



	// Configure the vertex and fragment shaders

	program, err = newProgram(vertexShader, fragmentShader)

	if err != nil {

		panic(err)

	}



	gl.UseProgram(program)



	projection = mgl32.Perspective(mgl32.DegToRad(45.0), float32(windowWidth)/windowHeight, 0.1, 10.0)

	projectionUniform := gl.GetUniformLocation(program, gl.Str("projection\x00"))

	gl.UniformMatrix4fv(projectionUniform, 1, false, &projection[0])



	camera = mgl32.LookAtV(mgl32.Vec3{3, 3, 3}, mgl32.Vec3{0, 0, 0}, mgl32.Vec3{0, 1, 0})

	cameraUniform := gl.GetUniformLocation(program, gl.Str("camera\x00"))

	gl.UniformMatrix4fv(cameraUniform, 1, false, &camera[0])



	model = mgl32.Ident4()

	modelUniform = gl.GetUniformLocation(program, gl.Str("model\x00"))

	gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])



	textureUniform := gl.GetUniformLocation(program, gl.Str("tex\x00"))

	gl.Uniform1i(textureUniform, 0)



	gl.BindFragDataLocation(program, 0, gl.Str("outputColor\x00"))



	// Load the texture

	texture, err = newTexture("/home/MUEHMER/bsmr/go/src/repositories.muehmer.net/bsmrgo/graphics-playground/scenes/gldemo/square.png")

	if err != nil {

		log.Fatalln(err)

	}



	// Configure the vertex data

	gl.GenVertexArrays(1, &vao)

	gl.BindVertexArray(vao)



	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))



	// Configure global settings

	gl.Enable(gl.DEPTH_TEST)

	gl.DepthFunc(gl.LESS)

	gl.ClearColor(1.0, 1.0, 1.0, 1.0)



	angle = 0.0

	previousTime = glfw.GetTime()



}



// Resize changes the view.

func resize(width, height int) {

	fmt.Fprintf(os.Stderr, "[%s] Resize(%d, %d)\n", sceneName, width, height)

}



// Render something.

func render() {

	gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)



	// Update

	time := glfw.GetTime()

	elapsed := time - previousTime

	previousTime = time



	angle += elapsed

	model = mgl32.HomogRotate3D(float32(angle), mgl32.Vec3{0, 1, 0})



	// Render

	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)



}



func keyCallback(w *glfw.Window, key glfw.Key, scancode int, action glfw.Action, mods glfw.ModifierKey) {

	fmt.Fprintf(os.Stderr, "[%s] key: %v - scancode: %d - action: %v - mode: %v\n", sceneName, key, scancode, action, mods)

	if key == glfw.KeyEscape && action == glfw.Press {

		w.SetShouldClose(true)

	}

}



func newProgram(vertexShaderSource, fragmentShaderSource string) (uint32, error) {

	vertexShader, err := compileShader(vertexShaderSource, gl.VERTEX_SHADER)

	if err != nil {

		return 0, err

	}



	fragmentShader, err := compileShader(fragmentShaderSource, gl.FRAGMENT_SHADER)

	if err != nil {

		return 0, err

	}



	program := gl.CreateProgram()



	gl.AttachShader(program, vertexShader)

	gl.AttachShader(program, fragmentShader)

	gl.LinkProgram(program)



	var status int32

	gl.GetProgramiv(program, gl.LINK_STATUS, &status)

	if status == gl.FALSE {

		var logLength int32

		gl.GetProgramiv(program, gl.INFO_LOG_LENGTH, &logLength)



		log := strings.Repeat("\x00", int(logLength+1))

		gl.GetProgramInfoLog(program, logLength, nil, gl.Str(log))



		return 0, fmt.Errorf("failed to link program: %v", log)

	}



	gl.DeleteShader(vertexShader)

	gl.DeleteShader(fragmentShader)



	return program, nil

}



func compileShader(source string, shaderType uint32) (uint32, error) {

	shader := gl.CreateShader(shaderType)



	csources, free := gl.Strs(source)

	gl.ShaderSource(shader, 1, csources, nil)

	free()

	gl.CompileShader(shader)



	var status int32

	gl.GetShaderiv(shader, gl.COMPILE_STATUS, &status)

	if status == gl.FALSE {

		var logLength int32

		gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, &logLength)



		log := strings.Repeat("\x00", int(logLength+1))

		gl.GetShaderInfoLog(shader, logLength, nil, gl.Str(log))



		return 0, fmt.Errorf("failed to compile %v: %v", source, log)

	}



	return shader, nil

}



func newTexture(file string) (uint32, error) {

	imgFile, err := os.Open(file)

	if err != nil {

		return 0, fmt.Errorf("texture %q not found on disk: %v", file, err)

	}

	img, _, err := image.Decode(imgFile)

	if err != nil {

		return 0, err

	}



	rgba := image.NewRGBA(img.Bounds())

	if rgba.Stride != rgba.Rect.Size().X*4 {

		return 0, fmt.Errorf("unsupported stride")

	}

	draw.Draw(rgba, rgba.Bounds(), img, image.Point{0, 0}, draw.Src)



	var texture uint32

	gl.GenTextures(1, &texture)

	gl.ActiveTexture(gl.TEXTURE0)

	gl.BindTexture(gl.TEXTURE_2D, texture)

	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)

	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)

	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)

	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)

	gl.TexImage2D(

		gl.TEXTURE_2D,

		0,

		gl.RGBA,

		int32(rgba.Rect.Size().X),

		int32(rgba.Rect.Size().Y),

		0,

		gl.RGBA,

		gl.UNSIGNED_BYTE,

		gl.Ptr(rgba.Pix))



	return texture, nil

}



var vertexShader = `

#version 330



uniform mat4 projection;

uniform mat4 camera;

uniform mat4 model;



in vec3 vert;

in vec2 vertTexCoord;



out vec2 fragTexCoord;



void main() {

    fragTexCoord = vertTexCoord;

    gl_Position = projection * camera * model * vec4(vert, 1);

}

` + "\x00"



var fragmentShader = `

#version 330



uniform sampler2D tex;



in vec2 fragTexCoord;



out vec4 outputColor;



void main() {

    outputColor = texture(tex, fragTexCoord);

}

` + "\x00"



var cubeVertices = []float32{

	//  X, Y, Z, U, V

	// Bottom

	-1.0, -1.0, -1.0, 0.0, 0.0,

	1.0, -1.0, -1.0, 1.0, 0.0,

	-1.0, -1.0, 1.0, 0.0, 1.0,

	1.0, -1.0, -1.0, 1.0, 0.0,

	1.0, -1.0, 1.0, 1.0, 1.0,

	-1.0, -1.0, 1.0, 0.0, 1.0,



	// Top

	-1.0, 1.0, -1.0, 0.0, 0.0,

	-1.0, 1.0, 1.0, 0.0, 1.0,

	1.0, 1.0, -1.0, 1.0, 0.0,

	1.0, 1.0, -1.0, 1.0, 0.0,

	-1.0, 1.0, 1.0, 0.0, 1.0,

	1.0, 1.0, 1.0, 1.0, 1.0,



	// Front

	-1.0, -1.0, 1.0, 1.0, 0.0,

	1.0, -1.0, 1.0, 0.0, 0.0,

	-1.0, 1.0, 1.0, 1.0, 1.0,

	1.0, -1.0, 1.0, 0.0, 0.0,

	1.0, 1.0, 1.0, 0.0, 1.0,

	-1.0, 1.0, 1.0, 1.0, 1.0,



	// Back

	-1.0, -1.0, -1.0, 0.0, 0.0,

	-1.0, 1.0, -1.0, 0.0, 1.0,

	1.0, -1.0, -1.0, 1.0, 0.0,

	1.0, -1.0, -1.0, 1.0, 0.0,

	-1.0, 1.0, -1.0, 0.0, 1.0,

	1.0, 1.0, -1.0, 1.0, 1.0,



	// Left

	-1.0, -1.0, 1.0, 0.0, 1.0,

	-1.0, 1.0, -1.0, 1.0, 0.0,

	-1.0, -1.0, -1.0, 0.0, 0.0,

	-1.0, -1.0, 1.0, 0.0, 1.0,

	-1.0, 1.0, 1.0, 1.0, 1.0,

	-1.0, 1.0, -1.0, 1.0, 0.0,



	// Right

	1.0, -1.0, 1.0, 1.0, 1.0,

	1.0, -1.0, -1.0, 1.0, 0.0,

	1.0, 1.0, -1.0, 0.0, 0.0,

	1.0, -1.0, 1.0, 1.0, 1.0,

	1.0, 1.0, -1.0, 0.0, 0.0,

	1.0, 1.0, 1.0, 0.0, 1.0,

}

scenes/gldemo/square.png

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