/
skybox.go
168 lines (138 loc) · 3.42 KB
/
skybox.go
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package main
import (
mgl "github.com/go-gl/mathgl/mgl32"
"golang.org/x/mobile/gl"
)
// TODO: Load this from an .obj file in the asset repository?
var skyboxVertices = []float32{
-1, 1, -1,
-1, -1, -1,
1, -1, -1,
1, 1, -1,
-1, -1, 1,
-1, 1, 1,
1, -1, 1,
1, 1, 1,
}
var skyboxNormals = []float32{
-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 skyboxIndices = []uint8{
0, 1, 2, 2, 3, 0,
4, 1, 0, 0, 5, 4,
2, 6, 7, 7, 3, 2,
4, 5, 7, 7, 6, 4,
0, 3, 7, 7, 5, 0,
1, 4, 2, 2, 4, 6,
}
func NewSkybox(shader Shader, texture gl.Texture) Drawable {
skyboxShape := NewStaticShape()
skyboxShape.vertices = skyboxVertices
skyboxShape.indices = skyboxIndices
skyboxShape.Buffer()
skyboxShape.Texture = texture
skybox := &Skybox{
StaticShape: skyboxShape,
shader: shader,
}
return skybox
}
type Skybox struct {
*StaticShape
shader Shader
}
func (shape *Skybox) Transform(parent *mgl.Mat4) mgl.Mat4 {
return mgl.Ident4()
}
func (node *Skybox) UseShader(parent Shader) (Shader, bool) {
if parent == node.shader {
return parent, false
}
node.shader.Use()
return node.shader, true
}
func (shape *Skybox) Draw(camera Camera) {
shader := shape.shader
gl.DepthFunc(gl.LEQUAL)
gl.DepthMask(false)
projection, view := camera.Projection(), camera.View().Mat3().Mat4()
gl.UniformMatrix4fv(shader.Uniform("projection"), projection[:])
gl.UniformMatrix4fv(shader.Uniform("view"), view[:])
gl.BindTexture(gl.TEXTURE_CUBE_MAP, shape.Texture)
gl.BindBuffer(gl.ARRAY_BUFFER, shape.VBO)
gl.EnableVertexAttribArray(shader.Attrib("vertCoord"))
gl.VertexAttribPointer(shader.Attrib("vertCoord"), vertexDim, gl.FLOAT, false, shape.Stride(), 0)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, shape.IBO)
gl.DrawElements(gl.TRIANGLES, len(shape.indices), gl.UNSIGNED_BYTE, 0)
gl.DisableVertexAttribArray(shader.Attrib("vertCoord"))
gl.DepthMask(true)
gl.DepthFunc(gl.LESS)
}
var floorVertices = []float32{
-100, 0, -100,
100, 0, -100,
100, 0, 100,
100, 0, 100,
-100, 0, -100,
-100, 0, 100,
}
var floorNormals = []float32{
0, 1, 0,
0, 1, 0,
0, 1, 0,
0, 1, 0,
0, 1, 0,
0, 1, 0,
}
type Floor struct {
Node
reflected []Drawable
}
func (scene *Floor) Draw(camera Camera) {
shader, _ := scene.UseShader(nil)
gl.Enable(gl.STENCIL_TEST)
gl.StencilFunc(gl.ALWAYS, 1, 0xFF)
gl.StencilOp(gl.KEEP, gl.KEEP, gl.REPLACE)
gl.StencilMask(0xFF)
gl.DepthMask(false)
gl.Clear(gl.STENCIL_BUFFER_BIT)
// Draw floor
gl.Uniform3fv(shader.Uniform("material.ambient"), []float32{0.1, 0.1, 0.1})
scene.Shape.Draw(shader, camera)
// Draw reflections
gl.StencilFunc(gl.EQUAL, 1, 0xFF)
gl.StencilMask(0x00)
gl.DepthMask(true)
view := camera.View()
gl.Uniform3fv(shader.Uniform("material.ambient"), []float32{0.3, 0.3, 0.3})
for _, node := range scene.reflected {
model := node.Transform(scene.transform)
gl.UniformMatrix4fv(shader.Uniform("model"), model[:])
normal := model.Mul4(view).Inv().Transpose()
gl.UniformMatrix4fv(shader.Uniform("normalMatrix"), normal[:])
node.Draw(camera)
}
gl.Disable(gl.STENCIL_TEST)
}
func NewFloor(shader Shader, reflected ...Drawable) Drawable {
floor := NewStaticShape()
floor.vertices = floorVertices
floor.normals = floorNormals
floor.Buffer()
flipped := mgl.Scale3D(1, -1, 1)
return &Floor{
Node: Node{
Shape: floor,
transform: &flipped,
shader: shader,
},
reflected: reflected,
}
}