I’ve done so much since my last update. I have a bunch of screenshots on my desktop just waiting to be uploaded here. I’ll try to submit a “real” update this weekend.
I just wanted to post to mention that I have uploaded a new tutorial series on YouTube regarding learning shader programming! The playlist for the series is here: https://www.youtube.com/playlist?list=PLT6WFYYZE6uJco3V9_Ssq2VPRIXCPUEsE
Finally done the porting of where I was when I left off on the swift side!
Commiting this code and ready to resume actual game development!
One of the reasons why love game programming so much is that it forces you to do things that would otherwise seem quite ridiculous. I have always liked to shoot first and ask questions later when it comes to implementing an idea. Sometimes it’ll just pop in my head and then I will start working on it and before I know it…it’s done. The last week and a half has been more work than I ever wanted to do but the result is awesome. A very large portion of my entire Verto Studio graphics engine and code base has now been rewritten in C++ and is now portable to any operating system.
This means I can now load and render my Verto Studio files on Windows, Linux, anything I want without any strict dependencies on Mac anymore. As a game developer, this is an awesome feeling and I am beyond stoked. I worked very hard on the Verto Studio tech over the last three years and to finally free it from OSX/iOS is great.
I’ve moved on the actual swift code of the in-progress Driveby Gangster Game project and hopefully I’ll have that done soon next week. All-in-all I’d say the extra week of work was definitely worth it.
Too much talk about code lately on here.
Here’s some latest screenshots. Before my decision to switch languages, I completely finished off the “practice mode”
I also recorded a gif during my testing with the bullet collision detection against arbitrary polygons in the scene.
So it had to happen…
The more I work on this game the more I realize that I kind of like it… and that means there’s certain things need to change. For starters, it’s definitely running longer than I expected it to (the original two-week estimate now sounds pretty “out there”). For this reason, I need to shave down on the programming time. It has become pretty obvious to me that for every 1/2 hour that I spend writing code in swift for this game, 10 minutes of it is spent screwing around with the language and that is friction then I can no longer accept. So I’m dropping swift for this game.
Since I’m switching languages and I’m going to be rewriting some code, I decided to open things up quite a bit and go back to C++. It’s going to cost me roughly a week or two to rewrite things, but the benefit is going to be huge. For starters, since this game depended on my very large and very complicated Objective-C graphics engine (Verto Studio), I now have the “opportunity” to continue rewriting all of this code in C++ (this was originally started on my github as VGLPP). This means that this game and any other game that I want to use with the ported engine will be able to run on ANY platform including windows. This is a major win for me since making a game for OSX/iOS only isn’t really that smart. I’ve been wanting to do this for awhile and my frustrations with swift finally pushed me to do it.
So that’s what I’m going to be up to for awhile. As I’ve mentioned on twitter, I’ll be streaming roughly twice a week on my twitch channel for anyone who is curiuos about the process and wants to follow along. http://twitch.tv/vertostudio3d
I’ve already gotten quite a bit done and have surpassed my biggest barrier for doing this which was finding a reasonable way to parse verto studio files (spat out by NSKeyedArchiver/NSCoder objective-c mechanisms) in a portable way in C++. TinyXML and a little of reverse engineering did the trick.
With respect to all of the “benefits” swift and Objective C were providing over a lower level language such as C++, I’ve essentially found a reasonable replacement for each one thanks to C++11′s new features.
| Swift/Objc | C++11 |
| Strong Pointer (Reference Counting) | std::shared_ptr |
| Weak Pointer (Reference Counting) | std::weak_ptr |
| Blocks & Closures | Lambda Functions |
| Protocols | Multiple Inheritence |
| Dynamic Typechecking via “isKindOfClass” | C++ typeid / RTTI |
So you get the idea, nothings really out of reach with C++. It’s still more annoying and I’m not 100% thrilled with dealing with things like templates, header files and verbose syntax again, but I’ll take it over an unstable language any day.
I’ve been less active on here because I’ve been writing quite a bit of code. Like I said previously, I’m in the main swing of developing this game. This is where things start to get crazy. Namely, I’ve added quite a bit of classes to the project to handle everything from basic collisions and 3D math extensions to generating and displaying 3D text on the screen. I feel like (despite my previous post regarding Swift) things are keeping organized quite well and I haven’t strayed too far from my original architecture plan. I’ve spent most of my time working on the PracticeGameStateRunner class which runs the “Target Practice” initial level in the game. This mini level serves as a point for the player to learn the very simple controls and game mechanics of the game… and it’s serving excellently as a sandbox for me to test these all during development as well.
I’ll cover just a few pieces of code today to show the changes that I’ve made regarding the game State Runner protocol, and some cool stuff that I’ve been able to do with “smart” enums in swift. There’s a lot more I can talk about that I don’t want this post to go on forever.
State runner protocol. Now I have some stuff in there to quickly respond to “game controller” and mouse events, all stemming from the game loop class.
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//
// GameState.swift
// Gangster Driveby
//
// Created by Mike Farrell on 10/15/14.
// Copyright (c) 2014 Mike Farrell. All rights reserved.
//
import Foundation
protocol GameStateRunner
{
func processLogic(#delta: Float)
func processEvents()
func render()
func keyDown(keysym: SDL_Keycode)
func keyUp(keysym: SDL_Keycode)
func mouseMoved(event: SDL_MouseMotionEvent)
func mouseDown(event: SDL_MouseButtonEvent)
func mouseUp(event: SDL_MouseButtonEvent)
func joystickDown(controllerButton button: GangsterGameLoop.ControllerButton)
func joystickUp(controllerButton button: GangsterGameLoop.ControllerButton)
} |
Mesh Line Collider – a badly needed construct to determine whether or not a bullet-trajectory would intersect a polygonal mesh in the scene or not (and if so where). I tried porting this over to ObjC before swift and it was a nitemare. Swift’s version is definitely simpler thanks to operator overloading and multiple return values. Note the unsafe pointer craziness in swift which is considerably easier to deal with in C. (ported from http://geomalgorithms.com/a06-_intersect-2.html)
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//
// MeshLineCollider.swift
// Gangster Driveby
//
// Created by Mike Farrell on 10/30/14.
// Copyright (c) 2014 Mike Farrell. All rights reserved.
//
import Foundation
class MeshLineCollider
{
weak var entity: Entity!
var boundingBoxCollider: MeshLineCollider?
let verts: GrowableArray
let faceIndices: GrowableArray
init(meshEntity: Entity)
{
entity = meshEntity
verts = entity.editVerts.mutableCopy() as GrowableArray
entity.applyTransformToVerts(verts, andNorms: nil)
let s: SubMesh = entity.submeshes[0] as SubMesh
faceIndices = s.editInds.mutableCopy() as GrowableArray
generateBoundingBoxCollider()
}
init(verts: GrowableArray, faces: GrowableArray)
{
self.verts = verts
faceIndices = faces
boundingBoxCollider = nil
}
convenience init(var verts: [float3], var faces: [uint3])
{
let vBuffer = UnsafeMutableBufferPointer(start: &verts, count: verts.count)
let vgArray = GrowableArray(data: vBuffer.baseAddress, ofSize: Int32(verts.count), andElementSize:Int32(sizeof(float3)), andExtraCapacity: 0)
let fBuffer = UnsafeMutableBufferPointer<uint3>(start: &faces, count: faces.count)
let fArray = GrowableArray(data: fBuffer.baseAddress, ofSize: Int32(faces.count*3), andElementSize:Int32(sizeof(uint)), andExtraCapacity: 0)
self.init(verts: vgArray, faces: fArray)
}
private final func split(quad: uint4) -> (uint3, uint3)
{
return (uint3(x: quad.x, y: quad.y, z: quad.w), uint3(x: quad.w, y: quad.y, z: quad.z))
}
private func generateBoundingBoxCollider()
{
var bbSize = float3.zero
entity.getBBox(&bbSize)
let box = Box3D(dimensions: bbSize, andPosition: float3.zero)
let boxVerts = box.generateVertices()
entity.applyTransformToVerts(boxVerts, andNorms: nil)
var boxInds: [uint4] = [ ]
boxInds.append(uint4(x: 0, y: 1, z: 2, w: 3))
boxInds.append(uint4(x: 0, y: 4, z: 5, w: 1))
boxInds.append(uint4(x: 2, y: 6, z: 7, w: 3))
boxInds.append(uint4(x: 3, y: 7, z: 4, w: 0))
boxInds.append(uint4(x: 1, y: 5, z: 6, w: 2))
boxInds.append(uint4(x: 4, y: 5, z: 6, w: 7))
var triangles: [uint3] = [ ]
for quad in boxInds
{
let spl = split(quad)
triangles.append(spl.0)
triangles.append(spl.1)
}
let fBuffer = UnsafeMutableBufferPointer<uint3>(start: &triangles, count: triangles.count)
let fArray = GrowableArray(data: fBuffer.baseAddress, ofSize: Int32(triangles.count*3), andElementSize:Int32(sizeof(uint)), andExtraCapacity: 0)
boundingBoxCollider = MeshLineCollider(verts: boxVerts, faces: fArray)
}
func debugRender()
{
if boundingBoxCollider != nil
{
boundingBoxCollider?.debugRender()
return
}
glDisable(GL_CULL_FACE.e)
glDepthRange(0.0, 0.9999);
let vgl = VertoGLStateMachine.currentMachine()
vgl.vertexPointerOfSize(3, type: GL_FLOAT.e, stride: 0, pointer: verts.data, bufferLength: GLsizeiptr(Int32(sizeof(float3))*verts.count))
vgl.setPrimaryColor(makeFloat4(0.2, 0.2, 0.2, 1))
vgl.prepareToDraw()
vgl.drawElementsInMode(GL_TRIANGLES.e, andCount: GLsizei(faceIndices.count), type: GL_UNSIGNED_INT.e, indexPointer: faceIndices.data,
bufferLength: GLsizeiptr(Int32(sizeof(uint))*faceIndices.count))
glDepthRange(0.0, 1.0);
}
//MARK: - Collision with line
func rayIntersection(rayOrigin ro: float3, rayDirection rd: float3, inout intersectionPoint: float3) -> IntersectionPoint?
{
if let bbox = boundingBoxCollider
{
if bbox.rayIntersection(rayOrigin: ro, rayDirection: rd, intersectionPoint: &intersectionPoint) == nil
{
return nil
}
}
let pointSet = IntersectionPointSet()
for i in 0..<faceIndices.count/3
{
let result = triangleIntersection(triangleIndex: Int(i), rayOrigin: ro, rayDirection: rd, intersectionPoint: &intersectionPoint)
if result.0
{
pointSet.add(IntersectionPoint(distance: result.1, point: intersectionPoint))
}
}
if !pointSet.empty()
{
return pointSet.nearest()
}
return nil
}
private func triangleIntersection(triangleIndex i: Int, rayOrigin ro: float3, rayDirection rd: float3, inout intersectionPoint ip: float3) -> (Bool, Float)
{
let smallNum: Float = 0.00000001
var u: float3, v: float3, n: float3 // triangle vectors
var dir: float3, w0: float3, w: float3 // ray vectors
var r: Float, a: Float, b: Float // params to calc ray-plane intersect
let vData = UnsafeMutableBufferPointer<float3>(start: UnsafeMutablePointer<float3>(verts.data), count: Int(verts.count))
let iData = UnsafeMutableBufferPointer<uint3>(start: UnsafeMutablePointer<uint3>(faceIndices.data), count: Int(faceIndices.count/3))
let v0 = vData[Int(iData[i].x)], v1 = vData[Int(iData[i].y)], v2 = vData[Int(iData[i].z)]
// get triangle edge vectors and plane normal
u = v1 - v0
v = v2 - v0
n = u.cross(v) // cross product
if n == float3.zero // triangle is degenerate
{
// do not deal with this case
return (false, 0)
}
dir = rd
w0 = ro - v0
a = -n.dot(w0)
b = n.dot(dir)
if fabsf(b) < smallNum
{
return (false, 0)
}
// get intersect point of ray with triangle plane
r = a / b
if r < 0.0 // ray goes away from triangle
{
return (false, 0) // => no intersect
}
// for a segment, also test if (r > 1.0) => no intersect
// intersect point of ray and plane
ip = ro + dir*r
// is I inside T?
var uu: Float, uv: Float, vv: Float, wu: Float, wv: Float, D: Float
uu = u.dot(u)
uv = u.dot(v)
vv = v.dot(v)
w = ip - v0
wu = w.dot(u)
wv = w.dot(v)
D = uv * uv - uu * vv
// get and test parametric coords
var s: Float, t: Float
s = (uv * wv - vv * wu) / D
if s < 0.0 || s > 1.0 // I is outside T
{
return (false, 0)
}
t = (uv * wu - uu * wv) / D
if t < 0.0 || (s + t) > 1.0 // I is outside T
{
return (false, 0)
}
return (true, r) // I is in T
}
} |
Cool little WIP controller button enum nested in the game loop class
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enum ControllerButton: Int
{
case Shoot = 9
case Aim = 8
var name: String
{
let buttonNames: [ControllerButton: String] = [ .Shoot: "Shoot", .Aim: "Aim" ]
return buttonNames[self]!
}
var obj: NSNumber
{
return NSNumber(integer: self.rawValue)
}
} |
