func CreateSprite(t Texture) (s Sprite, err error) {
s.texture = t
s.shader, err = CreateShader(vertexShader, fragmentShader)
if err != nil {
return s, err
}
gl.GenBuffers(1, &s.ebo)
gl.GenBuffers(1, &s.vbo)
gl.GenVertexArrays(1, &s.vao)
gl.BindVertexArray(s.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, s.vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, s.ebo)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(indices)*4, gl.Ptr(indices), gl.STATIC_DRAW)
err = s.shader.SetAttrib("vert", 2, gl.FLOAT, 4*4, 0)
err = s.shader.SetAttrib("vertTexCoord", 2, gl.FLOAT, 4*4, 2*4)
gl.BindVertexArray(0)
return s, err
}
// Updating the list of Points that this LineRender should be rendering.
func (lr *LineRender) UpdatePoints(points []Point) {
// Determining the buffer mode.
var mode uint32
if lr.static {
mode = gl.STATIC_DRAW
} else {
mode = gl.DYNAMIC_DRAW
}
// Setting the number of points.
lr.points = int32(len(points))
// Generating the buffer data.
vboData := generateVBOData(points)
eboData := generateEBOData(len(points))
// Filling the buffer data.
gl.BindVertexArray(lr.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, lr.vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(vboData)*4, gl.Ptr(vboData), mode)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, lr.ebo)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(eboData)*4, gl.Ptr(eboData), mode)
}
// Creating a RenderObject with a given shaderProgram, texture, and set of
// vertices.
func CreateRenderObject(shaderProgram ShaderProgram, texture Texture, vertices []float32) *RenderObject {
renderObject := new(RenderObject)
// Creating the basic information.
renderObject.shaderProgram = uint32(shaderProgram)
renderObject.texture = uint32(texture)
gl.GenVertexArrays(1, &renderObject.vao)
gl.GenBuffers(1, &renderObject.vbo)
gl.GenBuffers(1, &renderObject.ebo)
// Filling the RenderObject with information.
gl.BindVertexArray(renderObject.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, renderObject.vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, renderObject.ebo)
vertOrder := []uint32{
0, 1, 2,
2, 3, 0,
}
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertOrder)*4, gl.Ptr(vertOrder), gl.STATIC_DRAW)
// Loading up vertex attributes.
vertAttrib := uint32(gl.GetAttribLocation(renderObject.shaderProgram, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 2, gl.FLOAT, false, 4*4, gl.PtrOffset(0))
// Loading up texture attributes.
texAttrib := uint32(gl.GetAttribLocation(renderObject.shaderProgram, gl.Str("vertTexCoord\x00")))
gl.EnableVertexAttribArray(texAttrib)
gl.VertexAttribPointer(texAttrib, 2, gl.FLOAT, false, 4*4, gl.PtrOffset(2*4))
return renderObject
}
func createPlane(x0, y0, x1, y1 float32, verts [12]float32, indexes [6]uint32, uvs [8]float32, normals [12]float32) *Renderable {
const floatSize = 4
const uintSize = 4
r := NewRenderable()
gl.GenVertexArrays(1, &r.Vao)
r.FaceCount = 2
// create a VBO to hold the vertex data
gl.GenBuffers(1, &r.VertVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.VertVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(verts), gl.Ptr(&verts[0]), gl.STATIC_DRAW)
// create a VBO to hold the uv data
gl.GenBuffers(1, &r.UvVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.UvVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(uvs), gl.Ptr(&uvs[0]), gl.STATIC_DRAW)
// create a VBO to hold the normals data
gl.GenBuffers(1, &r.NormsVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.NormsVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(normals), gl.Ptr(&normals[0]), gl.STATIC_DRAW)
// create a VBO to hold the face indexes
gl.GenBuffers(1, &r.ElementsVBO)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.ElementsVBO)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, uintSize*len(indexes), gl.Ptr(&indexes[0]), gl.STATIC_DRAW)
return r
}
func (lr *LinesRenderer) Draw(line *LineGeometry, mv mgl32.Mat4, style *LineStyle) (err error) {
var (
dataBytes int = len(line.Vertices) * int(lr.stride)
indexBytes int = len(line.Indices) * int(lr.stride)
elementCount int32 = int32(len(line.Indices))
r, g, b, a = style.Color.RGBA()
)
gl.Uniform1f(lr.thicknessLoc, style.Thickness)
gl.Uniform1f(lr.innerLoc, style.Inner)
gl.Uniform4f(lr.colorLoc, float32(r)/255.0, float32(g)/255.0, float32(b)/255.0, float32(a)/255.0)
gl.UniformMatrix4fv(lr.modelviewLoc, 1, false, &mv[0])
if dataBytes > lr.bufferBytes {
lr.bufferBytes = dataBytes
gl.BufferData(gl.ARRAY_BUFFER, dataBytes, gl.Ptr(line.Vertices), gl.STREAM_DRAW)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, indexBytes, gl.Ptr(line.Indices), gl.STREAM_DRAW)
} else {
gl.BufferSubData(gl.ARRAY_BUFFER, 0, dataBytes, gl.Ptr(line.Vertices))
gl.BufferSubData(gl.ELEMENT_ARRAY_BUFFER, 0, indexBytes, gl.Ptr(line.Indices))
}
gl.DrawElements(gl.TRIANGLES, elementCount, gl.UNSIGNED_INT, gl.PtrOffset(0))
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR: OpenGL error %X", e)
}
return
}
func (t *Text) SetString(fs string, argv ...interface{}) {
var indices []rune
if len(argv) == 0 {
indices = []rune(fs)
} else {
indices = []rune(fmt.Sprintf(fs, argv...))
}
if len(indices) == 0 {
return
}
if t.MaxRuneCount > 0 && len(indices) > t.MaxRuneCount+1 {
indices = indices[0:t.MaxRuneCount]
}
t.String = string(indices)
// ebo, vbo data
glfloat_size := int32(4)
t.vboIndexCount = len(indices) * 4 * 2 * 2 // 4 indexes per rune (containing 2 position + 2 texture)
t.eboIndexCount = len(indices) * 6 // each rune requires 6 triangle indices for a quad
t.RuneCount = len(indices)
t.vboData = make([]float32, t.vboIndexCount, t.vboIndexCount)
t.eboData = make([]int32, t.eboIndexCount, t.eboIndexCount)
// generate the basic vbo data and bounding box
t.X1 = Point{0, 0}
t.X2 = Point{0, 0}
t.makeBufferData(indices)
// find the centered position of the bounding box
lowerLeft := t.getLowerLeft()
// reposition the vbo data so that it is centered at (0,0)
// according to the orthographic projection being used
t.setDataPosition(lowerLeft)
if t.IsDebug {
fmt.Printf("bounding box %v %v\n", t.X1, t.X2)
fmt.Printf("lower left\n%v\n", lowerLeft)
fmt.Printf("text vbo data\n%v\n", t.vboData)
fmt.Printf("text ebo data\n%v\n", t.eboData)
}
gl.BindVertexArray(t.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, t.vbo)
gl.BufferData(
gl.ARRAY_BUFFER, int(glfloat_size)*t.vboIndexCount, gl.Ptr(t.vboData), gl.DYNAMIC_DRAW)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, t.ebo)
gl.BufferData(
gl.ELEMENT_ARRAY_BUFFER, int(glfloat_size)*t.eboIndexCount, gl.Ptr(t.eboData), gl.DYNAMIC_DRAW)
gl.BindVertexArray(0)
// not necesssary, but i just want to better understand using vertex arrays
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
// SetString can be called at anytime. we want to make sure that if the user is updating the text,
// the previous position will be maintained
t.SetPosition(t.SetPositionX, t.SetPositionY)
}
func createElementArrayBuffer(data []uint16) uint32 {
var name uint32
gl.GenBuffers(1, &name)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, name)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(data)*2 /* total bytes */, gl.Ptr(data), gl.STATIC_DRAW)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
return name
}
func createArrayBuffer(data []float32) uint32 {
var name uint32
gl.GenBuffers(1, &name)
gl.BindBuffer(gl.ARRAY_BUFFER, name)
gl.BufferData(gl.ARRAY_BUFFER, len(data)*4 /* total bytes */, gl.Ptr(data), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
return name
}
//InitPostProcessSystem will allocate all the resources required to make the Image Post Processing system work.
func InitPostProcessSystem() {
//init model
quadvao := gl2.GenVertexArray()
quadvao.Bind()
defer quadvao.Unbind()
vertpos := gl2.GenBuffer()
vertpos.Bind(gl.ARRAY_BUFFER)
gl.BufferData(gl.ARRAY_BUFFER, len(_quadvertpos)*2*4, ptr(_quadvertpos), gl.STATIC_DRAW)
vertuv := gl2.GenBuffer()
vertuv.Bind(gl.ARRAY_BUFFER)
gl.BufferData(gl.ARRAY_BUFFER, len(_quadvertuv)*2*4, ptr(_quadvertuv), gl.STATIC_DRAW)
fstri.vao = quadvao
fstri.pos = vertpos
fstri.uv = vertuv
}
func (b *GLBuffer) Upload(data interface{}, size int) {
b.Bind()
if size > b.bufferBytes {
b.bufferBytes = size
gl.BufferData(b.target, size, gl.Ptr(data), gl.STREAM_DRAW)
} else {
gl.BufferSubData(b.target, 0, size, gl.Ptr(data))
}
}
//CreateVertexArray is a "constructor" of vertex array, hence returns a opengl
//mesh, specifically a cube for testing
func CreateVertexArray() VertexArray {
var vertexArray VertexArray
cubeVertices := vertexArray.PosData()
gl.GenVertexArrays(1, &vertexArray.handleVAO)
gl.BindVertexArray(vertexArray.handleVAO)
gl.GenBuffers(1, &vertexArray.handleVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, vertexArray.handleVBO)
gl.BufferData(gl.ARRAY_BUFFER, len(cubeVertices)*4, gl.Ptr(cubeVertices), gl.STATIC_DRAW)
return vertexArray
}
func Draw() {
// if len(layers) == 0 {
// fmt.Println("layers empty!!!")
// return
// }
// for _, layer := range layers {
// vertexData := textureHash[layer]
vertexData := &vertexDataTest
// check to see if there are any vertices at all to draw
if len(vertexData.vertexData) == 0 {
return
}
// vertexData.Print()
// vertexData := vertexDataTest
//vertexData.Print()
// BindBuffers(vertexData)
// vertexData.Print()
//gl.BufferSubData(gl.ARRAY_BUFFER, 0, len(vertexData.VertexData)*4, gl.Ptr(vertexData.VertexData))
// gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(vertexData.vertexData)*4, gl.Ptr(vertexData.vertexData), gl.DYNAMIC_DRAW)
// gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementvbo)
// gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertexData.Elements)*4, gl.Ptr(vertexData.Elements), gl.DYNAMIC_DRAW)
MVP := projectionM.Mul4(viewM) //.Mul4(Model)
gl.UniformMatrix4fv(MVPid, 1, false, &MVP[0])
lightPos := mathgl.Vec3{0, 3, 10}
lightintensities := mathgl.Vec3{1, .4, .2}
gl.Uniform3f(lightpositionID, lightPos[0], lightPos[1], lightPos[2])
gl.Uniform3f(lightintensitiesID, lightintensities[0], lightintensities[1], lightintensities[2])
gl.Uniform3f(cameraPositionID, 0.0, 1.0, -1.0)
// vertexData.Print()
// gl.DrawElements(gl.TRIANGLES, int32(len(vertexData.Elements)), gl.UNSIGNED_INT, nil)
// }
numTriVerts := int32((len(vertexData.vertexData) / (int(NUM_ATTRIBUTES) * 2)) * 3)
gl.DrawArrays(gl.TRIANGLES, 0, numTriVerts)
ClearVertexData()
}
func BindBuffers() { //vertexData *OpenGLVertexInfo) {
vertexData := &vertexDataTest
// check to see if there are any vertices at all to bind
if len(vertexData.vertexData) == 0 {
return
}
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(vertexData.vertexData)*4, gl.Ptr(vertexData.vertexData), gl.DYNAMIC_DRAW)
positionAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vertexPosition_modelspace\x00")))
gl.EnableVertexAttribArray(positionAttrib)
gl.VertexAttribPointer(positionAttrib, 3, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(0))
colorAttrib := uint32(gl.GetAttribLocation(program, gl.Str("diffuse\x00")))
gl.EnableVertexAttribArray(colorAttrib)
gl.VertexAttribPointer(colorAttrib, 4, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(3*4))
uvAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vertexUV\x00")))
gl.EnableVertexAttribArray(uvAttrib)
gl.VertexAttribPointer(uvAttrib, 2, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(7*4))
mNormAttrib := uint32(gl.GetAttribLocation(program, gl.Str("mNorm\x00")))
gl.EnableVertexAttribArray(mNormAttrib)
gl.VertexAttribPointer(mNormAttrib, 3, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(9*4))
wNormAttrib := uint32(gl.GetAttribLocation(program, gl.Str("wNorm\x00")))
gl.EnableVertexAttribArray(wNormAttrib)
gl.VertexAttribPointer(wNormAttrib, 3, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(12*4))
shaderMode := uint32(gl.GetAttribLocation(program, gl.Str("mode\x00")))
gl.EnableVertexAttribArray(shaderMode)
gl.VertexAttribPointer(shaderMode, 1, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(15*4))
samplerIdx := uint32(gl.GetAttribLocation(program, gl.Str("samplerIdx\x00")))
gl.EnableVertexAttribArray(samplerIdx)
gl.VertexAttribPointer(samplerIdx, 1, gl.FLOAT, false, 4*NUM_ATTRIBUTES, gl.PtrOffset(16*4))
// gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementvbo)
// gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertexData.Elements)*4, gl.Ptr(vertexData.Elements), gl.STATIC_DRAW)
// gl.ActiveTexture(gl.TEXTURE0)
// gl.BindTexture(gl.TEXTURE_2D, 1)
}
func CreateVBO(size int, data interface{}, usage uint32) (buffer uint32, err error) {
gl.GenBuffers(1, &buffer)
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR gl.GenBuffer %X", e)
return
}
gl.BindBuffer(gl.ARRAY_BUFFER, buffer)
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR buffer.Bind %X", e)
return
}
gl.BufferData(gl.ARRAY_BUFFER, size, gl.Ptr(data), usage)
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR gl.BufferData %X", e)
return
}
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR buffer.Unbind %X", e)
return
}
return
}
func (r *Framerate) Render(camera *core.Camera) (err error) {
r.data.Sample()
var (
modelView = mgl32.Ident4()
dataBytes int = int(r.data.Count) * int(r.stride)
)
gl.Uniform4f(r.locColor, 255.0/255.0, 0, 0, 255.0/255.0)
gl.UniformMatrix4fv(r.locModelView, 1, false, &modelView[0])
gl.UniformMatrix4fv(r.locProjection, 1, false, &camera.Projection[0])
if dataBytes > r.vboBytes {
r.vboBytes = dataBytes
gl.BufferData(gl.ARRAY_BUFFER, dataBytes, gl.Ptr(r.data.Points), gl.STREAM_DRAW)
} else {
gl.BufferSubData(gl.ARRAY_BUFFER, 0, dataBytes, gl.Ptr(r.data.Points))
}
gl.DrawArrays(gl.POINTS, 0, r.data.Count)
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR: OpenGL error %X", e)
}
return
}
// CreateSphere generates a 3d uv-sphere with the given radius and returns a Renderable.
func CreateSphere(radius float32, rings int, sectors int) *Renderable {
// nothing to create
if rings < 2 || sectors < 2 {
return nil
}
const piDiv2 = math.Pi / 2.0
verts := make([]float32, 0, rings*sectors)
indexes := make([]uint32, 0, rings*sectors)
uvs := make([]float32, 0, rings*sectors)
normals := make([]float32, 0, rings*sectors)
R := float64(1.0 / float32(rings-1))
S := float64(1.0 / float32(sectors-1))
for ri := 0; ri < int(rings); ri++ {
for si := 0; si < int(sectors); si++ {
y := float32(math.Sin(-piDiv2 + math.Pi*float64(ri)*R))
x := float32(math.Cos(2.0*math.Pi*float64(si)*S) * math.Sin(math.Pi*float64(ri)*R))
z := float32(math.Sin(2.0*math.Pi*float64(si)*S) * math.Sin(math.Pi*float64(ri)*R))
uvs = append(uvs, float32(si)*float32(S))
uvs = append(uvs, float32(ri)*float32(R))
verts = append(verts, x*radius)
verts = append(verts, y*radius)
verts = append(verts, z*radius)
normals = append(normals, x)
normals = append(normals, y)
normals = append(normals, z)
currentRow := ri * sectors
nextRow := (ri + 1) * sectors
indexes = append(indexes, uint32(currentRow+si))
indexes = append(indexes, uint32(nextRow+si))
indexes = append(indexes, uint32(nextRow+si+1))
indexes = append(indexes, uint32(currentRow+si))
indexes = append(indexes, uint32(nextRow+si+1))
indexes = append(indexes, uint32(currentRow+si+1))
}
}
r := NewRenderable()
gl.GenVertexArrays(1, &r.Vao)
r.FaceCount = rings * sectors * 2
const floatSize = 4
const uintSize = 4
// create a VBO to hold the vertex data
gl.GenBuffers(1, &r.VertVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.VertVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(verts), gl.Ptr(&verts[0]), gl.STATIC_DRAW)
// create a VBO to hold the uv data
gl.GenBuffers(1, &r.UvVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.UvVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(uvs), gl.Ptr(&uvs[0]), gl.STATIC_DRAW)
// create a VBO to hold the normals data
gl.GenBuffers(1, &r.NormsVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.NormsVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(normals), gl.Ptr(&normals[0]), gl.STATIC_DRAW)
// create a VBO to hold the face indexes
gl.GenBuffers(1, &r.ElementsVBO)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.ElementsVBO)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, uintSize*len(indexes), gl.Ptr(&indexes[0]), gl.STATIC_DRAW)
return r
}
func CreateContext(width, height int) Context {
vertexShader := `
#version 330
uniform mat4 projection;
uniform mat4 camera;
uniform mat4 model;
in vec3 vert;
void main() {
gl_Position = projection * camera * model * vec4(vert, 1);
}
` + "\x00"
fragmentShader := `
#version 330
uniform vec4 color;
out vec4 outputColor;
void main() {
outputColor = color;
}
` + "\x00"
vertices := []float32{
0.0, 0.0, 0.0,
1.0, 0.0, 0.0,
1.0, 1.0, 0.0,
1.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 0.0, 0.0,
}
if err := glfw.Init(); err != nil {
log.Fatalln("failed to initialize glfw:", err)
}
// defer glfw.Terminate()
glfw.WindowHint(glfw.Resizable, glfw.False)
glfw.WindowHint(glfw.ContextVersionMajor, 3)
glfw.WindowHint(glfw.ContextVersionMinor, 3)
glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
window, err := glfw.CreateWindow(width, height, "OpenGL", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
if err := gl.Init(); err != nil {
panic(err)
}
program, err := newProgram(vertexShader, fragmentShader)
if err != nil {
panic(err)
}
gl.UseProgram(program)
projection := mgl32.Ortho2D(0, 800, 0, 600)
projectionUniform := gl.GetUniformLocation(program, gl.Str("projection\x00"))
gl.UniformMatrix4fv(projectionUniform, 1, false, &projection[0])
camera := mgl32.LookAtV(mgl32.Vec3{0, 0, 0.5}, 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])
var vao uint32
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(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
vertAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 3*4, gl.PtrOffset(0))
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
return Context{Window: window, program: program}
}
func main() {
vertices, normals := obj.Parse(os.Args[1])
// initialize GLFW
if err := glfw.Init(); err != nil {
panic(err)
}
defer glfw.Terminate()
// set opengl core profile 3.3
glfw.WindowHint(glfw.ContextVersionMajor, 3)
glfw.WindowHint(glfw.ContextVersionMinor, 3)
glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
window, err := glfw.CreateWindow(640, 480, "GOpenGL", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
// initialise OpenGL library
if err := gl.Init(); err != nil {
panic(err)
}
// link program from shaders
program, err := newProgram("vertex.glsl", "fragment.glsl")
if err != nil {
panic(err)
}
gl.UseProgram(program)
// vertex attribute object holds links between attributes and vbo
var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
// vertex buffer with per-vertex data
var vbo [2]uint32
gl.GenBuffers(2, &vbo[0])
// position data
gl.BindBuffer(gl.ARRAY_BUFFER, vbo[0])
gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
// set up position attribute with layout of vertices
posAttrib := uint32(gl.GetAttribLocation(program, gl.Str("position\x00")))
gl.VertexAttribPointer(posAttrib, 3, gl.FLOAT, false, 3*4, gl.PtrOffset(0))
gl.EnableVertexAttribArray(posAttrib)
// normal data
gl.BindBuffer(gl.ARRAY_BUFFER, vbo[1])
gl.BufferData(gl.ARRAY_BUFFER, len(normals)*4, gl.Ptr(normals), gl.STATIC_DRAW)
normAttrib := uint32(gl.GetAttribLocation(program, gl.Str("normal\x00")))
gl.VertexAttribPointer(normAttrib, 3, gl.FLOAT, false, 3*4, gl.PtrOffset(0))
gl.EnableVertexAttribArray(normAttrib)
uniModel := gl.GetUniformLocation(program, gl.Str("model\x00"))
uniView := gl.GetUniformLocation(program, gl.Str("view\x00"))
uniProj := gl.GetUniformLocation(program, gl.Str("proj\x00"))
matView := mgl32.LookAt(2.0, 2.0, 2.0,
0.0, 0.0, 0.0,
0.0, 0.0, 1.0)
gl.UniformMatrix4fv(uniView, 1, false, &matView[0])
matProj := mgl32.Perspective(mgl32.DegToRad(45.0), 640.0/480.0, 1.0, 10.0)
gl.UniformMatrix4fv(uniProj, 1, false, &matProj[0])
uniLightDir := gl.GetUniformLocation(program, gl.Str("lightDir\x00"))
uniLightCol := gl.GetUniformLocation(program, gl.Str("lightCol\x00"))
gl.Uniform3f(uniLightDir, -0.5, 0.0, -1.0)
gl.Uniform3f(uniLightCol, 0.0, 0.5, 0.5)
startTime := glfw.GetTime()
gl.Enable(gl.DEPTH_TEST)
gl.ClearColor(1.0, 1.0, 1.0, 1.0)
for !window.ShouldClose() {
// clear buffer
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
matRot := mgl32.HomogRotate3DZ(float32(glfw.GetTime() - startTime))
gl.UniformMatrix4fv(uniModel, 1, false, &matRot[0])
gl.DrawArrays(gl.TRIANGLES, 0, int32(len(vertices)))
window.SwapBuffers()
glfw.PollEvents()
}
}
func (c *Chunk) buildLandscapeRenderable() *fizzle.Renderable {
var xmax, ymax, zmax float32 = 1.0, 1.0, 1.0
var xmin, ymin, zmin float32 = 0.0, 0.0, 0.0
/* Cube vertices are layed out like this:
+--------+ 6 5
/ | /|
+--------+ | 1 0 +Y
| | | | |___ +X
| +------|-+ 7 4 /
|/ |/ +Z
+--------+ 2 3
*/
verts := [...]float32{
xmax, ymax, zmax, xmin, ymax, zmax, xmin, ymin, zmax, xmax, ymin, zmax, // v0,v1,v2,v3 (front)
xmax, ymax, zmin, xmax, ymax, zmax, xmax, ymin, zmax, xmax, ymin, zmin, // v5,v0,v3,v4 (right)
xmax, ymax, zmin, xmin, ymax, zmin, xmin, ymax, zmax, xmax, ymax, zmax, // v5,v6,v1,v0 (top)
xmin, ymax, zmax, xmin, ymax, zmin, xmin, ymin, zmin, xmin, ymin, zmax, // v1,v6,v7,v2 (left)
xmax, ymin, zmax, xmin, ymin, zmax, xmin, ymin, zmin, xmax, ymin, zmin, // v3,v2,v7,v4 (bottom)
xmin, ymax, zmin, xmax, ymax, zmin, xmax, ymin, zmin, xmin, ymin, zmin, // v6,v5,v4,v7 (back)
}
indexes := [...]uint32{
0, 1, 2, 2, 3, 0,
}
uvs := [...]float32{
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
}
normals := [...]float32{
0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, // v0,v1,v2,v3 (front)
1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, // v5,v0,v3,v4 (right)
0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, // v5,v6,v1,v0 (top)
-1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, // v1,v6,v7,v2 (left)
0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, // v3,v2,v7,v4 (bottom)
0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, // v6,v5,v4,v7 (back)
}
sectorVerts := make([]float32, 0, len(verts)*ChunkSize3)
sectorNormals := make([]float32, 0, len(verts)*ChunkSize3)
sectorIndexes := make([]uint32, 0, len(indexes)*ChunkSize3)
sectorUVs := make([]float32, 0, len(uvs)*ChunkSize3)
const comboFloatsPerGrid int = len(verts)
sectorCombo := make([]float32, 0, comboFloatsPerGrid*ChunkSize3)
var faceCount uint32
// create some temporary buffers
instVerts := make([]float32, 12)
instIndexes := make([]uint32, 6)
instNorms := make([]float32, 12)
instCombo := make([]float32, 12)
// loop through each block
for y := 0; y < ChunkSize; y++ {
for x := 0; x < ChunkSize; x++ {
for z := 0; z < ChunkSize; z++ {
worldX := c.X*ChunkSize + x
worldY := c.Y*ChunkSize + y
worldZ := c.Z*ChunkSize + z
// if the block itself is not visible, then just move on
if c.IsBlockVisible(x, y, z) == false {
continue
}
// get the block
block := c.BlockAt(x, y, z)
// process each face on the block separately
currentFaceCount := 0
for face := 0; face < 6; face++ {
// do we need this face? check to see if there's an obstructing block.
// NOTE: this is done with a lame implementation right now, because
// going back to the manager isn't efficient.
switch {
case face == 0:
b, _ := c.Owner.GetBlockAt(worldX, worldY, worldZ+1)
if b != nil && b.Type > 0 {
continue
}
case face == 1:
b, _ := c.Owner.GetBlockAt(worldX+1, worldY, worldZ)
if b != nil && b.Type > 0 {
continue
}
case face == 2:
b, _ := c.Owner.GetBlockAt(worldX, worldY+1, worldZ)
if b != nil && b.Type > 0 {
continue
}
case face == 3:
b, _ := c.Owner.GetBlockAt(worldX-1, worldY, worldZ)
if b != nil && b.Type > 0 {
continue
}
case face == 4:
b, _ := c.Owner.GetBlockAt(worldX, worldY-1, worldZ)
if b != nil && b.Type > 0 {
continue
}
case face == 5:
b, _ := c.Owner.GetBlockAt(worldX, worldY, worldZ-1)
if b != nil && b.Type > 0 {
continue
}
}
// time to make the vertices
baseV := face * 12
for iv := 0; iv < 4; iv++ {
iv3 := iv * 3
instVerts[iv3] = verts[baseV+iv3] + float32(x)
instVerts[iv3+1] = verts[baseV+iv3+1] + float32(y)
instVerts[iv3+2] = verts[baseV+iv3+2] + float32(z)
// add the normals too
instNorms[iv3] = normals[baseV+iv3]
instNorms[iv3+1] = normals[baseV+iv3+1]
instNorms[iv3+2] = normals[baseV+iv3+2]
// add the combo, per-vertex data as well
instCombo[iv3] = float32(block.Color[0]) / 256.0
instCombo[iv3+1] = float32(block.Color[1]) / 256.0
instCombo[iv3+2] = float32(block.Color[2]) / 256.0
}
// time to make the element indeces
for iv := 0; iv < 6; iv++ {
instIndexes[iv] = indexes[iv] + uint32(currentFaceCount*4) + uint32(faceCount*2)
}
sectorVerts = append(sectorVerts, instVerts...)
sectorIndexes = append(sectorIndexes, instIndexes...)
sectorUVs = append(sectorUVs, uvs[:]...)
sectorNormals = append(sectorNormals, instNorms...)
sectorCombo = append(sectorCombo, instCombo...)
// we're not skiping the face, so lets boost the count
currentFaceCount += 1
}
faceCount += uint32(currentFaceCount) * 2
} // z
} // x
} // y
// if we didn't make any faces, just stop here and return an empty renderable
r := fizzle.NewRenderable()
r.Core = fizzle.NewRenderableCore()
if faceCount < 1 {
return r
}
r.ShaderName = "landscape"
r.FaceCount = faceCount
r.BoundingRect.Top[0] = ChunkSize
r.BoundingRect.Top[1] = ChunkSize
r.BoundingRect.Top[2] = ChunkSize
r.Location[0] = float32(c.X * ChunkSize)
r.Location[1] = float32(c.Y * ChunkSize)
r.Location[2] = float32(c.Z * ChunkSize)
r.Core.DiffuseColor[0] = 1.0
r.Core.DiffuseColor[1] = 1.0
r.Core.DiffuseColor[2] = 1.0
r.Core.DiffuseColor[3] = 1.0
r.Core.SpecularColor[0] = 1.0
r.Core.SpecularColor[1] = 1.0
r.Core.SpecularColor[2] = 1.0
r.Core.SpecularColor[3] = 1.0
r.Core.Shininess = 0.00
// calculate the memory size of floats used to calculate total memory size of float arrays
const floatSize = 4
const uintSize = 4
//groggy.Logsf("DEBUG", "buildLandscapeRenderable() v:%d, uv:%d, n:%d, elem:%d, faces:%d", len(sectorVerts), len(sectorUVs), len(sectorNormals), len(sectorIndexes), faceCount)
// create a VBO to hold the vertex data
gl.GenBuffers(1, &r.Core.VertVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.Core.VertVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(sectorVerts), gl.Ptr(§orVerts[0]), gl.STATIC_DRAW)
// create a VBO to hold the uv data
gl.GenBuffers(1, &r.Core.UvVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.Core.UvVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(sectorUVs), gl.Ptr(§orUVs[0]), gl.STATIC_DRAW)
// create a VBO to hold the normals data
gl.GenBuffers(1, &r.Core.NormsVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.Core.NormsVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(sectorNormals), gl.Ptr(§orNormals[0]), gl.STATIC_DRAW)
// create a VBO to hold the combo data
gl.GenBuffers(1, &r.Core.ComboVBO1)
gl.BindBuffer(gl.ARRAY_BUFFER, r.Core.ComboVBO1)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(sectorCombo), gl.Ptr(§orCombo[0]), gl.STATIC_DRAW)
// create a VBO to hold the face indexes
gl.GenBuffers(1, &r.Core.ElementsVBO)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.Core.ElementsVBO)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, uintSize*len(sectorIndexes), gl.Ptr(§orIndexes[0]), gl.STATIC_DRAW)
return r
}
func main() {
// init glfw
if err := glfw.Init(); err != nil {
panic(err)
}
defer glfw.Terminate()
glfw.WindowHint(glfw.Resizable, glfw.False)
glfw.WindowHint(glfw.ContextVersionMajor, 4)
glfw.WindowHint(glfw.ContextVersionMinor, 1)
glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
// make an application window
window, err := glfw.CreateWindow(windowWidth, windowHeight, "Hello", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
// init gl
if err := gl.Init(); err != nil {
panic(err)
}
fmt.Println("OpenGL version", gl.GoStr(gl.GetString(gl.VERSION)))
// create vertex & fragment shader
program, err := newProgram(vertexShader, fragmentShader)
if err != nil {
panic(err)
}
gl.UseProgram(program)
gl.BindFragDataLocation(program, 0, gl.Str("fc\x00"))
points := []float32{
-0.5, -0.5,
0.5, 0.5,
0.5, -0.5,
-0.5, 0.5,
}
vertices := []uint32{
0, 2, 1, 3,
}
// configure the vertex data
var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
defer gl.BindVertexArray(0)
var vbo uint32
gl.GenBuffers(1, &vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(points)*4, gl.Ptr(points), gl.STATIC_DRAW)
var ibo uint32
gl.GenBuffers(1, &ibo)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ibo)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
vertAttrib := uint32(gl.GetAttribLocation(program, gl.Str("pv\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 2, gl.FLOAT, false, 2*4, gl.PtrOffset(0))
// global settings
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(1.0, 1.0, 1.0, 1.0)
for !window.ShouldClose() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
gl.UseProgram(program)
gl.BindVertexArray(vao)
gl.DrawElements(gl.LINE_LOOP, 4, gl.UNSIGNED_INT, gl.PtrOffset(0))
window.SwapBuffers()
glfw.PollEvents()
}
}
func (tr *SpriteRenderer) Draw(instances []SpriteConfig) error {
var (
bytesNeeded int
byteoffset int
count int32
data unsafe.Pointer
float float32 = 0
floatSize uint32
i uint32
offset unsafe.Pointer
sprite SpriteConfig
stride int32
)
floatSize = uint32(unsafe.Sizeof(float))
stride = int32(unsafe.Sizeof(sprite))
gl.UseProgram(tr.program)
gl.Uniform1i(tr.textureUnitLoc, 0)
// Instance data binding
gl.BindBuffer(gl.ARRAY_BUFFER, tr.instanceVBO)
count = int32(len(instances))
bytesNeeded = int(stride * count)
data = gl.Ptr(instances)
if bytesNeeded > tr.instanceBytes {
gl.BufferData(gl.ARRAY_BUFFER, bytesNeeded, data, gl.STREAM_DRAW)
tr.instanceBytes = bytesNeeded
} else {
gl.BufferSubData(gl.ARRAY_BUFFER, 0, bytesNeeded, data)
}
gl.EnableVertexAttribArray(tr.translationLoc)
gl.VertexAttribPointer(tr.translationLoc, 3, gl.FLOAT, false, stride, tr.offAttrX)
gl.VertexAttribDivisor(tr.translationLoc, 1)
gl.EnableVertexAttribArray(tr.rotationLoc)
gl.VertexAttribPointer(tr.rotationLoc, 3, gl.FLOAT, false, stride, tr.offAttrRotationX)
gl.VertexAttribDivisor(tr.rotationLoc, 1)
gl.EnableVertexAttribArray(tr.scaleLoc)
gl.VertexAttribPointer(tr.scaleLoc, 3, gl.FLOAT, false, stride, tr.offAttrScaleX)
gl.VertexAttribDivisor(tr.scaleLoc, 1)
gl.EnableVertexAttribArray(tr.colorLoc)
gl.VertexAttribPointer(tr.colorLoc, 4, gl.FLOAT, false, stride, tr.offAttrColor)
gl.VertexAttribDivisor(tr.colorLoc, 1)
for i = 0; i < 4; i++ {
byteoffset = int(i * 4 * floatSize)
offset = gl.PtrOffset(tr.offAttrPointAdj + byteoffset)
gl.EnableVertexAttribArray(tr.pointAdjLoc + i)
gl.VertexAttribPointer(tr.pointAdjLoc+i, 4, gl.FLOAT, false, stride, offset)
gl.VertexAttribDivisor(tr.pointAdjLoc+i, 1)
offset = gl.PtrOffset(tr.offAttrTextureAdj + byteoffset)
gl.EnableVertexAttribArray(tr.textureAdjLoc + i)
gl.VertexAttribPointer(tr.textureAdjLoc+i, 4, gl.FLOAT, false, stride, offset)
gl.VertexAttribDivisor(tr.textureAdjLoc+i, 1)
}
// Projection
gl.UniformMatrix4fv(tr.projectionLoc, 1, false, &tr.Renderer.Camera.Projection[0])
// Actually draw.
gl.DrawArraysInstanced(gl.TRIANGLES, 0, 6, int32(len(instances)))
// Undo instance attr repetition.
gl.VertexAttribDivisor(tr.translationLoc, 0)
gl.VertexAttribDivisor(tr.rotationLoc, 0)
gl.VertexAttribDivisor(tr.scaleLoc, 0)
gl.VertexAttribDivisor(tr.colorLoc, 0)
for i = 0; i < 4; i++ {
gl.VertexAttribDivisor(tr.pointAdjLoc+i, 0)
gl.VertexAttribDivisor(tr.textureAdjLoc+i, 0)
}
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
return nil
}
func loadBoundingBox(f *Font, X1 Point, X2 Point) (b *BoundingBox, err error) {
b = new(BoundingBox)
b.font = f
// create shader program and define attributes and uniforms
b.program, err = NewProgram(boxVertexShaderSource, boxFragmentShaderSource)
if err != nil {
return b, err
}
// ebo, vbo data
b.vboIndexCount = 4 * 2 // 4 indexes per bounding box (containing 2 position)
b.eboIndexCount = 6 // each rune requires 6 triangle indices for a quad
b.vboData = make([]float32, b.vboIndexCount, b.vboIndexCount)
b.eboData = make([]int32, b.eboIndexCount, b.eboIndexCount)
b.makeBufferData(X1, X2)
if f.IsDebug {
fmt.Printf("bounding %v %v\n", X1, X2)
fmt.Printf("bounding vbo data\n%v\n", b.vboData)
fmt.Printf("bounding ebo data\n%v\n", b.eboData)
}
// attributes
b.centeredPosition = uint32(gl.GetAttribLocation(b.program, gl.Str("centered_position\x00")))
// uniforms
b.finalPositionUniform = gl.GetUniformLocation(b.program, gl.Str("final_position\x00"))
b.orthographicMatrixUniform = gl.GetUniformLocation(b.program, gl.Str("orthographic_matrix\x00"))
// size of glfloat
glfloatSize := int32(4)
gl.GenVertexArrays(1, &b.vao)
gl.GenBuffers(1, &b.vbo)
gl.GenBuffers(1, &b.ebo)
// vao
gl.BindVertexArray(b.vao)
// vbo
// specify the buffer for which the VertexAttribPointer calls apply
gl.BindBuffer(gl.ARRAY_BUFFER, b.vbo)
gl.EnableVertexAttribArray(b.centeredPosition)
gl.VertexAttribPointer(
b.centeredPosition,
2,
gl.FLOAT,
false,
0,
gl.PtrOffset(0),
)
gl.BufferData(gl.ARRAY_BUFFER, int(glfloatSize)*b.vboIndexCount, gl.Ptr(b.vboData), gl.DYNAMIC_DRAW)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, b.ebo)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int(glfloatSize)*b.eboIndexCount, gl.Ptr(b.eboData), gl.DYNAMIC_DRAW)
gl.BindVertexArray(0)
// not necesssary, but i just want to better understand using vertex arrays
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
return b, nil
}
// bindString generates all of the vertex buffers and vertex arrays for a single constant line of
// text. No error checking is done.
func (d *Dictionary) bindString(str string) strData {
var data strData
gl.GenVertexArrays(1, &data.varrays[0])
gl.BindVertexArray(data.varrays[0])
gl.GenBuffers(2, &data.vbuffers[0])
var positions, texcoords []float32
var pen pos
var prev rune
for _, r := range str {
ri := d.Runes[r]
var scale float32 = 1.0 / float32(d.GlyphMax.Dy())
var posMin, posMax pos
posMin.x = pen.x + float32(ri.GlyphBounds.Min.X)*scale
posMin.y = pen.y + float32(ri.GlyphBounds.Min.Y)*scale
posMax.x = pen.x + float32(ri.GlyphBounds.Max.X)*scale
posMax.y = pen.y + float32(ri.GlyphBounds.Max.Y)*scale
var texMin, texMax pos
texMin.x = float32(ri.PixBounds.Min.X) / float32(d.Dx)
texMin.y = float32(ri.PixBounds.Min.Y) / float32(d.Dy)
texMax.x = float32(ri.PixBounds.Max.X) / float32(d.Dx)
texMax.y = float32(ri.PixBounds.Max.Y) / float32(d.Dy)
pen.x += float32(ri.AdvanceWidth) * scale
pen.x += float32(d.Kerning[RunePair{prev, r}]) * scale
// pen.x -= float32(d.Kerning[RunePair{prev, r}]) * scale
positions = append(positions, posMin.x) // lower left
positions = append(positions, posMin.y)
positions = append(positions, posMin.x) // upper left
positions = append(positions, posMax.y)
positions = append(positions, posMax.x) // upper right
positions = append(positions, posMax.y)
positions = append(positions, posMin.x) // lower left
positions = append(positions, posMin.y)
positions = append(positions, posMax.x) // upper right
positions = append(positions, posMax.y)
positions = append(positions, posMax.x) // lower right
positions = append(positions, posMin.y)
texcoords = append(texcoords, texMin.x) // lower left
texcoords = append(texcoords, texMax.y)
texcoords = append(texcoords, texMin.x) // upper left
texcoords = append(texcoords, texMin.y)
texcoords = append(texcoords, texMax.x) // upper right
texcoords = append(texcoords, texMin.y)
texcoords = append(texcoords, texMin.x) // lower left
texcoords = append(texcoords, texMax.y)
texcoords = append(texcoords, texMax.x) // upper right
texcoords = append(texcoords, texMin.y)
texcoords = append(texcoords, texMax.x) // lower right
texcoords = append(texcoords, texMax.y)
prev = r
}
data.count = int32(len(positions))
gl.BindBuffer(gl.ARRAY_BUFFER, data.vbuffers[0])
gl.BufferData(gl.ARRAY_BUFFER, len(positions)*int(unsafe.Sizeof(positions[0])), gl.Ptr(&positions[0]), gl.STATIC_DRAW)
location, _ := render.GetAttribLocation("glop.font", "position")
gl.EnableVertexAttribArray(uint32(location))
gl.VertexAttribPointer(uint32(location), 2, gl.FLOAT, false, 0, gl.PtrOffset(0))
gl.BindBuffer(gl.ARRAY_BUFFER, data.vbuffers[1])
gl.BufferData(gl.ARRAY_BUFFER, len(texcoords)*int(unsafe.Sizeof(texcoords[0])), gl.Ptr(&texcoords[0]), gl.STATIC_DRAW)
location, _ = render.GetAttribLocation("glop.font", "texCoord")
gl.EnableVertexAttribArray(uint32(location))
gl.VertexAttribPointer(uint32(location), 2, gl.FLOAT, false, 0, gl.PtrOffset(0))
return data
}
func main() {
// init glfw
if err := glfw.Init(); err != nil {
panic(err)
}
defer glfw.Terminate()
glfw.WindowHint(glfw.Resizable, glfw.False)
glfw.WindowHint(glfw.ContextVersionMajor, 4)
glfw.WindowHint(glfw.ContextVersionMinor, 1)
glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
// make an application window
window, err := glfw.CreateWindow(windowWidth, windowHeight, "Transform", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
// init gl
if err := gl.Init(); err != nil {
panic(err)
}
fmt.Println("OpenGL version", gl.GoStr(gl.GetString(gl.VERSION)))
// create vertex & fragment shader
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])
gl.BindFragDataLocation(program, 0, gl.Str("vert\x00"))
points := []float32{
-0.9, -0.9, -0.9,
0.9, -0.9, -0.9,
0.9, -0.9, 0.9,
-0.9, -0.9, 0.9,
-0.9, 0.9, -0.9,
0.9, 0.9, -0.9,
0.9, 0.9, 0.9,
-0.9, 0.9, 0.9,
}
vertices := []uint32{
0, 1,
1, 2,
2, 3,
3, 0,
0, 4,
1, 5,
2, 6,
3, 7,
4, 5,
5, 6,
6, 7,
7, 4,
}
// configure the vertex data
var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
defer gl.BindVertexArray(0)
var vbo uint32
gl.GenBuffers(1, &vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(points)*4, gl.Ptr(points), gl.STATIC_DRAW)
var ibo uint32
gl.GenBuffers(1, &ibo)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ibo)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
vertAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 3*4, gl.PtrOffset(0))
// global settings
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(0.0, 0.0, 0.0, 1.0)
angleX := 0.0
angleY := 0.0
angleZ := 0.0
previousTime := glfw.GetTime()
for !window.ShouldClose() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
time := glfw.GetTime()
elapsed := time - previousTime
previousTime = time
angleX += math.Sin((elapsed / period) * math.Pi * 2.0)
angleY += math.Sin((elapsed / period) / 6.0 * math.Pi * 2.0)
angleZ += math.Sin((elapsed / period) / 3.0 * math.Pi * 2.0)
model = mgl32.HomogRotate3DY(float32(angleY)).Mul4(mgl32.HomogRotate3DX(float32(angleX))).Mul4(mgl32.HomogRotate3DZ(float32(angleZ)))
gl.UseProgram(program)
gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])
gl.BindVertexArray(vao)
gl.DrawElements(gl.LINES, int32(len(vertices)), gl.UNSIGNED_INT, gl.PtrOffset(0))
window.SwapBuffers()
glfw.PollEvents()
}
}
// CreateCube makes a new Renderable object with the specified dimensions for the cube.
func CreateCube(xmin, ymin, zmin, xmax, ymax, zmax float32) *Renderable {
/* Cube vertices are layed out like this:
+--------+ 6 5
/ | /|
+--------+ | 1 0 +Y
| | | | |___ +X
| +------|-+ 7 4 /
|/ |/ +Z
+--------+ 2 3
*/
verts := [...]float32{
xmax, ymax, zmax, xmin, ymax, zmax, xmin, ymin, zmax, xmax, ymin, zmax, // v0,v1,v2,v3 (front)
xmax, ymax, zmin, xmax, ymax, zmax, xmax, ymin, zmax, xmax, ymin, zmin, // v5,v0,v3,v4 (right)
xmax, ymax, zmin, xmin, ymax, zmin, xmin, ymax, zmax, xmax, ymax, zmax, // v5,v6,v1,v0 (top)
xmin, ymax, zmax, xmin, ymax, zmin, xmin, ymin, zmin, xmin, ymin, zmax, // v1,v6,v7,v2 (left)
xmax, ymin, zmax, xmin, ymin, zmax, xmin, ymin, zmin, xmax, ymin, zmin, // v3,v2,v7,v4 (bottom)
xmin, ymax, zmin, xmax, ymax, zmin, xmax, ymin, zmin, xmin, ymin, zmin, // v6,v5,v4,v7 (back)
}
indexes := [...]uint32{
0, 1, 2, 2, 3, 0,
4, 5, 6, 6, 7, 4,
8, 9, 10, 10, 11, 8,
12, 13, 14, 14, 15, 12,
16, 17, 18, 18, 19, 16,
20, 21, 22, 22, 23, 20,
}
uvs := [...]float32{
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
}
normals := [...]float32{
0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, // v0,v1,v2,v3 (front)
1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, // v5,v0,v3,v4 (right)
0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, // v5,v6,v1,v0 (top)
-1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, // v1,v6,v7,v2 (left)
0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, // v3,v2,v7,v4 (bottom)
0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, // v6,v5,v4,v7 (back)
}
r := NewRenderable()
gl.GenVertexArrays(1, &r.Vao)
r.FaceCount = 12
const floatSize = 4
const uintSize = 4
// create a VBO to hold the vertex data
gl.GenBuffers(1, &r.VertVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.VertVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(verts), gl.Ptr(&verts[0]), gl.STATIC_DRAW)
// create a VBO to hold the uv data
gl.GenBuffers(1, &r.UvVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.UvVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(uvs), gl.Ptr(&uvs[0]), gl.STATIC_DRAW)
// create a VBO to hold the normals data
gl.GenBuffers(1, &r.NormsVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.NormsVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(normals), gl.Ptr(&normals[0]), gl.STATIC_DRAW)
// create a VBO to hold the face indexes
gl.GenBuffers(1, &r.ElementsVBO)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.ElementsVBO)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, uintSize*len(indexes), gl.Ptr(&indexes[0]), gl.STATIC_DRAW)
return r
}