//
// Draw Loop Function
// This function gets called on every update.
//
func drawLoop(glw *wrapper.Glw) {
// Sets the Clear Color (Background Color)
gl.ClearColor(0.0, 0.0, 0.0, 1.0)
// Clears the Window
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
// Enables Depth
gl.Enable(gl.DEPTH_TEST)
// Sets the Shader program to Use
gl.UseProgram(shaderProgram)
// Define the model transformations for the cube
cube.ResetModel()
cube.Translate(x+0.5, y, z)
cube.Scale(scale, scale, scale) //scale equally in all axis
cube.Rotate(-angle_x, mgl32.Vec3{1, 0, 0}) //rotating in clockwise direction around x-axis
cube.Rotate(-angle_y, mgl32.Vec3{0, 1, 0}) //rotating in clockwise direction around y-axis
cube.Rotate(-angle_z, mgl32.Vec3{0, 0, 1}) //rotating in clockwise direction around z-axis
// Define the model transformations for our sphere
sphere.ResetModel()
sphere.Translate(-x-0.5, 0, 0)
sphere.Scale(scale/3.0, scale/3.0, scale/3.0) //scale equally in all axis
sphere.Rotate(-angle_x, mgl32.Vec3{1, 0, 0}) //rotating in clockwise direction around x-axis
sphere.Rotate(-angle_y, mgl32.Vec3{0, 1, 0}) //rotating in clockwise direction around y-axis
sphere.Rotate(-angle_z, mgl32.Vec3{0, 0, 1}) //rotating in clockwise direction around z-axis
// Projection matrix : 45° Field of View, 4:3 ratio, display range : 0.1 unit <-> 100 units
var Projection mgl32.Mat4 = mgl32.Perspective(30.0, aspect_ratio, 0.1, 100.0)
// Camera matrix
var View mgl32.Mat4 = mgl32.LookAtV(
mgl32.Vec3{0, 0, 4}, // Camera is at (0,0,4), in World Space
mgl32.Vec3{0, 0, 0}, // and looks at the origin
mgl32.Vec3{0, 1, 0}, // Head is up (set to 0,-1,0 to look upside-down)
)
// Send our uniforms variables to the currently bound shader,
gl.Uniform1ui(colourmodeUniform, uint32(colourmode))
gl.UniformMatrix4fv(viewUniform, 1, false, &View[0])
gl.UniformMatrix4fv(projectionUniform, 1, false, &Projection[0])
// Draws the Cube
gl.UniformMatrix4fv(modelUniform, 1, false, &cube.Model[0])
cube.Draw()
// Draw our sphere
gl.UniformMatrix4fv(modelUniform, 1, false, &sphere.Model[0])
sphere.DrawSphere()
gl.DisableVertexAttribArray(0)
gl.UseProgram(0)
/* Modify our animation variables */
angle_x += angle_inc_x
angle_y += angle_inc_y
angle_z += angle_inc_z
}
func (r *Renderer) Render() {
// defer glfw.Terminate()
shader := r.Shaders.textureFlat
program := shader.program
//
gl.UseProgram(program)
//
gl.BindFragDataLocation(program, 0, gl.Str("outputColor\x00"))
// // Configure global settings
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(1.0, 1.0, 1.0, 1.0)
//
// angle += elapsed
// r.Mesh.modelView = mgl32.HomogRotate3D(float32(angle), mgl32.Vec3{0, 1, 0})
// Render
// gl.UniformMatrix4fv(shader.uniforms["modelView"], 1, false, &r.Mesh.modelView[0])
time := glfw.GetTime()
_ = time - r.PreviousTime
r.PreviousTime = time
// fmt.Println(elapsed * 100)
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
gl.UniformMatrix4fv(shader.uniforms["projection"], 1, false, &r.Projection[0])
gl.UniformMatrix4fv(shader.uniforms["camera"], 1, false, &r.Camera[0])
// TODO : batch triangles and use multiple textures
for _, mesh := range r.Meshes {
gl.UniformMatrix4fv(shader.uniforms["modelView"], 1, false, &mesh.modelView[0])
gl.Uniform1i(shader.uniforms["tex"], 0)
gl.BindVertexArray(mesh.vao)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, mesh.textures[0])
gl.DrawArrays(gl.TRIANGLES, 0, int32(len(mesh.verticies)/5))
}
// Maintenance
r.Window.SwapBuffers()
glfw.PollEvents()
if r.Ready == false {
r.Ready = true
}
}
func (glr *GlRenderer) initScreen() {
var err error
glr.program, err = createScreenShader()
if err != nil {
panic(err)
}
gl.UseProgram(glr.program)
projection := mgl32.Ortho2D(-1, 1, 1, -1)
projectionUniform := gl.GetUniformLocation(glr.program, gl.Str("projection\x00"))
gl.UniformMatrix4fv(projectionUniform, 1, false, &projection[0])
textureUniform := gl.GetUniformLocation(glr.program, gl.Str("tex\x00"))
gl.Uniform1i(textureUniform, 0)
glr.texture = createScreenTexture(glr.width, glr.height)
gl.GenVertexArrays(1, &glr.vao)
gl.BindVertexArray(glr.vao)
var quadVertices = []float32{
// X, Y, Z, U, V
1.0, -1.0, 0.0, 1.0, 0.0,
-1.0, -1.0, 0.0, 0.0, 0.0,
1.0, 1.0, 0.0, 1.0, 1.0,
-1.0, -1.0, 0.0, 0.0, 0.0,
-1.0, 1.0, 0.0, 0.0, 1.0,
1.0, 1.0, 0.0, 1.0, 1.0,
}
var vbo uint32
gl.GenBuffers(1, &vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(quadVertices)*4, gl.Ptr(quadVertices), gl.STATIC_DRAW)
vertAttrib := uint32(gl.GetAttribLocation(glr.program, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 5*4, gl.PtrOffset(0))
texCoordAttrib := uint32(gl.GetAttribLocation(glr.program, gl.Str("vertTexCoord\x00")))
gl.EnableVertexAttribArray(texCoordAttrib)
gl.VertexAttribPointer(texCoordAttrib, 2, gl.FLOAT, false, 5*4, gl.PtrOffset(3*4))
gl.Enable(gl.DEPTH_TEST)
gl.ClearColor(1.0, 1.0, 1.0, 1.0)
}
func (shaderManager *ShaderManager) SetUniformMatrix4fv(shaderName, uniformName string, count int32, transpose bool, value *float32) {
gl.UniformMatrix4fv(shaderManager.GetUniform(shaderName, uniformName), count, transpose, value)
}
func (objectLoader *WavefrontObject) DrawObject(shaderProgram uint32) {
for _, object := range objectLoader.Objects {
// Reads the uniform Locations
modelUniform := gl.GetUniformLocation(shaderProgram, gl.Str("model\x00"))
ambientUniform := gl.GetUniformLocation(shaderProgram, gl.Str("ambient\x00"))
diffuseUniform := gl.GetUniformLocation(shaderProgram, gl.Str("diffuse\x00"))
specularUniform := gl.GetUniformLocation(shaderProgram, gl.Str("specular\x00"))
emissiveUniform := gl.GetUniformLocation(shaderProgram, gl.Str("emissive\x00"))
// Send our uniforms variables to the currently bound shader
if object.Material != nil {
gl.Uniform4f(ambientUniform, object.Material.KaR, object.Material.KaG, object.Material.KaB, object.Material.Tr) // Ambient colour.
gl.Uniform4f(diffuseUniform, object.Material.KdR, object.Material.KdG, object.Material.KdB, object.Material.Tr) // Diffuse colour.
gl.Uniform4f(specularUniform, object.Material.KsR, object.Material.KsG, object.Material.KsB, object.Material.Tr) // Specular colour.
gl.Uniform4f(emissiveUniform, object.Material.KeR, object.Material.KeG, object.Material.KeB, object.Material.Tr) // Emissive colour.
if object.Material.Texture != 0 {
textureUniform := gl.GetUniformLocation(shaderProgram, gl.Str("DiffuseTextureSampler\x00"))
gl.Uniform1i(textureUniform, 0)
normalTextureUniform := gl.GetUniformLocation(shaderProgram, gl.Str("NormalTextureSampler\x00"))
gl.Uniform1i(normalTextureUniform, 1)
specularTextureUniform := gl.GetUniformLocation(shaderProgram, gl.Str("SpecularTextureSampler\x00"))
gl.Uniform1i(specularTextureUniform, 2)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, object.Material.Texture)
gl.ActiveTexture(gl.TEXTURE1)
gl.BindTexture(gl.TEXTURE_2D, object.Material.NormalMap)
gl.ActiveTexture(gl.TEXTURE2)
gl.BindTexture(gl.TEXTURE_2D, object.Material.SpecularMap)
}
if object.Material.Tr < 1.0 {
// Enables Transparencies
gl.Enable(gl.BLEND)
// gl.BlendFunc(gl.SRC_COLOR, gl.ONE)
// gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
}
}
// Geometry
var size int32 // Used to get the byte size of the element (vertex index) array
gl.UniformMatrix4fv(modelUniform, 1, false, &object.Model[0])
// Get the vertices uniform position
verticesUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("position\x00")))
normalsUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("normal\x00")))
textureCoordinatesUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("texcoord\x00")))
// Describe our vertices array to OpenGL (it can't guess its format automatically)
gl.BindBuffer(gl.ARRAY_BUFFER, object.VertexBufferObjectVertices)
gl.VertexAttribPointer(
verticesUniform, // attribute index
3, // number of elements per vertex, here (x,y,z)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
gl.EnableVertexAttribArray(normalsUniform)
gl.BindBuffer(gl.ARRAY_BUFFER, object.VertexBufferObjectNormals)
gl.VertexAttribPointer(
normalsUniform, // attribute
3, // number of elements per vertex, here (x,y,z)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
gl.EnableVertexAttribArray(textureCoordinatesUniform)
gl.BindBuffer(gl.ARRAY_BUFFER, object.VertexBufferObjectTextureCoords)
gl.VertexAttribPointer(
textureCoordinatesUniform, // attribute
2, // number of elements per vertex, here (u,v)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
size = int32(len(object.Vertex))
gl.PointSize(3.0)
// Enable this line to show model in wireframe
switch objectLoader.DrawMode {
case 1:
gl.PolygonMode(gl.FRONT_AND_BACK, gl.LINE)
default:
gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL)
}
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, object.VertexBufferObjectFaces)
gl.GetBufferParameteriv(gl.ELEMENT_ARRAY_BUFFER, gl.BUFFER_SIZE, &size)
gl.DrawElements(gl.TRIANGLES, int32(len(object.Faces)), gl.UNSIGNED_SHORT, nil)
// gl.DrawElements(gl.POINTS, int32(len(object.Faces)), gl.UNSIGNED_SHORT, nil)
// Disables transparencies
gl.Disable(gl.BLEND)
}
}
/* Enable vertex attributes and draw object
Could improve efficiency by moving the vertex attribute pointer functions to the
create object but this method is more general
This code is almost untouched fomr the tutorial code except that I changed the
number of elements per vertex from 4 to 3*/
func (terrain *Terrain) DrawObject(shaderProgram uint32) {
toneUniform := gl.GetAttribLocation(shaderProgram, gl.Str("tone\x00"))
gl.Uniform4f(toneUniform, terrain.ColorTone.X(), terrain.ColorTone.Y(), terrain.ColorTone.Z(), terrain.ColorTone.W())
// gl.Uniform4f(toneUniform, 0.0, 1.0, 0.5, 1.0)
// gl.Uniform4fv(toneUniform, 1, &terrain.ColorTone[0])
// Reads the uniform Locations
modelUniform := gl.GetUniformLocation(shaderProgram, gl.Str("model\x00"))
// Send our uniforms variables to the currently bound shader
gl.UniformMatrix4fv(modelUniform, 1, false, &terrain.Model[0])
// Get the vertices uniform position
verticesUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("position\x00")))
normalsUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("normal\x00")))
colorsUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("colour\x00")))
// Describe our vertices array to OpenGL (it can't guess its format automatically)
gl.EnableVertexAttribArray(verticesUniform)
gl.BindBuffer(gl.ARRAY_BUFFER, terrain.VBOVertices)
gl.VertexAttribPointer(
verticesUniform, // attribute index
3, // number of elements per vertex, here (x,y,z)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
gl.EnableVertexAttribArray(normalsUniform)
gl.BindBuffer(gl.ARRAY_BUFFER, terrain.VBONormals)
gl.VertexAttribPointer(
normalsUniform, // attribute
3, // number of elements per vertex, here (x,y,z)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
gl.EnableVertexAttribArray(colorsUniform)
gl.BindBuffer(gl.ARRAY_BUFFER, terrain.VBOColors)
gl.VertexAttribPointer(
colorsUniform, // attribute
3, // number of elements per vertex, here (x,y,z)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
size := int32(len(terrain.Indices))
gl.PointSize(3.0)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, terrain.VBOIndices)
gl.GetBufferParameteriv(gl.ELEMENT_ARRAY_BUFFER, gl.BUFFER_SIZE, &size)
// Enable this line to show model in wireframe
switch terrain.DrawMode {
case 1:
gl.PolygonMode(gl.FRONT_AND_BACK, gl.LINE)
case 2:
gl.DrawArrays(gl.POINTS, 0, int32(len(terrain.Vertices)))
// gl.DrawElements(gl.POINTS, int32(len(terrain.Indices)), gl.UNSIGNED_SHORT, nil)
return
default:
gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL)
}
var location int = 0
/* Draw the triangle strips */
for i := uint32(0); i < terrain.XSize-1; i++ {
location = SizeOfUint16 * int(i*terrain.ZSize*2)
gl.DrawElements(gl.TRIANGLE_STRIP, int32(terrain.ZSize*2), gl.UNSIGNED_SHORT, gl.PtrOffset(location))
}
// gl.DrawElements(
// gl.TRIANGLE_STRIP,
// len(terrain.Indices),
// gl.UNSIGNED_SHORT,
// nil,
// )
}