diff options
| -rw-r--r-- | app.go | 13 | ||||
| -rw-r--r-- | geometry.go | 47 | ||||
| -rw-r--r-- | main.go | 2 |
3 files changed, 56 insertions, 6 deletions
@@ -18,11 +18,14 @@ const ( type App struct { window *glfw.Window graphics *Graphics + stl *StlModel + homeTrafo mgl32.Mat4 } -func newApp() App { +func newApp(stl *StlModel) App { var app App = App{} + app.stl = stl var err error log.Println("GLFW init") @@ -44,6 +47,8 @@ func newApp() App { } app.window.MakeContextCurrent() + app.homeTrafo = stl.surface.getHomeView() + return app } @@ -52,10 +57,8 @@ func (application *App) handle() { application.window.SwapBuffers() // generate and set transformation - var scale float32 = 0.01 - trafo := mgl32.Ident4() - trafo = trafo.Mul4(mgl32.HomogRotate3D(float32(glfw.GetTime()) * 3, mgl32.Vec3{0, 1, 1})) - trafo = trafo.Mul4(mgl32.Scale3D(scale, scale, scale)) + trafo := application.homeTrafo + trafo = mgl32.HomogRotate3D(float32(glfw.GetTime()) * 3, mgl32.Vec3{0, 1, 0}).Mul4(trafo) // apply time-based rotation application.graphics.setTrafo(trafo) } diff --git a/geometry.go b/geometry.go index 04896dc..1fc516a 100644 --- a/geometry.go +++ b/geometry.go @@ -2,6 +2,10 @@ package main +import ( + "github.com/go-gl/mathgl/mgl32" +) + // representation of a three-dimensional point in space type Point struct { scalars [3]float32 // x = scalars[0], y = scalars[1], z = scalars[2] @@ -17,3 +21,46 @@ type Surface struct { triangles []*Triangle } +// return a transformation to view the whole centered surface +func (s Surface) getHomeView() mgl32.Mat4 { + + // evaluating the smallest and biggest values for x,y,z of the surface + var min,max [3]float32 + for _,triangle := range(s.triangles) { + for _,point := range(triangle.points) { + for index,_ := range(min) { + if point.scalars[index] < min[index] { + min[index] = point.scalars[index] + } + if point.scalars[index] > max[index] { + max[index] = point.scalars[index] + } + } + } + } + + // calculate center point + var center Point + for index,_ := range(min) { + center.scalars[index] = (min[index] + max[index]) / 2 + } + + // calculate zoom + var zoom,zoomX,zoomY float32 + const fillFactor float32 = 0.8 + zoomX = (2 / (max[0] - min[0])) * fillFactor + zoomY = (2 / (max[1] - min[1])) * fillFactor + if zoomX > zoomY { + zoom = zoomY + } else { + zoom = zoomX + } + + // calculate and return transformation + var trafo mgl32.Mat4 = mgl32.Ident4() + trafo = mgl32.Translate3D(-center.scalars[0], -center.scalars[1], -center.scalars[2]).Mul4(trafo) + trafo = mgl32.Scale3D(zoom, zoom, zoom).Mul4(trafo) + + return trafo +} + @@ -28,7 +28,7 @@ func main() { vertices = stl.toVertices() // initialize application (includes GLFW/window) - var app App = newApp() + var app App = newApp(&stl) defer app.terminate() // GLFW needs to be terminated! // initialize graphics |