The "Discussion" link links to a Google Group "angel-engine" that no longer exists.

ref: glfw/glfw@e7c7ebf

I am using Angel2d on a retina macbook pro. Although Angel2d has some support for high resolution screens (an excellent feature in a cross-platform game engine!), there are some issues.

• GWEN UI elements are drawn with incorrect sizesand, sometimes, at incorrect locations.
• The mouse coordinates for picking the GWEN UI elements are significantly shifted from where they should be.
• If a window is moved from a retina screen to a conventional screen, or vice versa, GWEN UI elements disappear entirely.
• World::SetSideBlockers works incorrectly -- blockers exist but are far outside the window boundaries.

I will follow up with some thoughts on fixing these issues.

Screenshots from IntroGame:

In the function World::DrawDebugLines:

void World::DrawDebugLine(const Vector2& a, const Vector2& b, float time, const Color& color)
{
    DebugLine* line = new DebugLine();
    line->_points[0] = a.X;
    line->_points[1] = a.Y;
    line->_points[2] = b.X;
    line->_points[3] = a.Y; // <-- Should be b.Y
    line->_color = color;
    line->_timeRemaining = time;
    line->_bPermanent = (time < 0);
    _debugDrawItems.push_back(line);
}

You can see that the line line->_points[3] = a.Y; should be line->_points[3] = b.Y;.

I will submit a pull request with the fix momentarily.

Angel2D uses float for it's floating point data type, for intermediate values, long term storage, and as a conversion medium. Unfortunately, float has significant disadvantages for all of these applications.

--- Support ---
All platforms that Angel2D supports have hardware support for float and double at roughly the same speed.
On x86/x64, SSE only supports 4 float's; however, SSE2 supports two double's, and has been available and standard since the Pentium 4.
On ARM (iOS, Android, Windows RT), double is supported on all available platforms, and is as fast as float. Only on new iPhone's with a NEON chip is float substantially faster, and usually only with use of intrinsics.
On PowerPC, the pipeline is designed for double; rounding to single is slower than using double exclusively.

--- Performance ---
On all platforms, long double is at least as big as double (and on linux/mac, is a true extended precision type), and only on PowerPC it is it slower than float or double.
PowerPC uses double double math; this is slightly slower (measurements indicate around 5%).

--- Hardware ---
On x86/x64, all operations actually occur in long double, internally.
On ARM, all operations occur in their specified type.
On PowerPC, all operations occur on double.

--- Intermediate Values ---
Not all numbers are directly representable in floating points.
If a number cannot be represented, an approximation is used.

Most operations on floating points result in an increase in digits.
ex. 10.5 * 10.5 = 100.25
If we only had 3 digits to store in, we would store 100.2, with an error of 0.05
Multiplication can lead to twice as many digits as we put in.
Transcendental operations (sin,cos,etc) can be much worse.

By using a larger type than we intend to store in, we keep as many significant figures as possible. Even if we round down at the end, using larger values for intermediates means no loss of significant figures.

Using float for everything means our result can have half as much precision as we started with!

--- Long Term Storage ---
OpenGL does not use doubles, but it often does not use float either; 24 bit floats are still common, and 16 bit "half"s were (and are) often used internally. Using float means inaccurate intermediate values to (possibly) avoid a double to single (or less) conversion to the "sink".

Furthermore, Lua uses double exclusively, and GLFW returns them regularly; many of the libraries do. Using float discards valuable precision from these "sources", resulting in substantially few significant figures to work with.

--- Conversions ---
Angel uses float as if it can safely store and restore an int. It cannot.

Single precision floating points have 24 bits to their significand.
int is 32 bits, 8 less than float can store.

Converting an int to a float is risky, and causes significant problems.

Double precision floating points have 54 bits in their significand.
They can easily store an int, signed or unsigned.
This is why lua uses double exclusively.

--- Recommended Changes ---
Use double instead of float where ever applicable
Use long double for intermediate values
Change Vector2/3 to use double
Directly use/copy lua values (instead of using userdata) for Vector2/3

--- Possible Alternative ---
Make a two float vector into a standard lua type. This would be possible with either default lua or luaJIT, and make Vector2 a first class Lua object.
Annotate Vector2 with intrinsics for speed.

--- Conclusions ---
The only reason float could possibly be preferred for use is because it is faster or smaller (and thus faster), but on any platform used by Angel it is not faster, much less safe, and requires large amounts of boilerplate to accommodate (adding f to constants is cumbersome and easy to miss).

As Angel is based on being understandable instead of performant, uses Lua as it's primary scripting language (which uses double exclusively), and uses C++ as it's main language (which makes all constants double), double should be the preferred type for floating points in Angel.

The messaging system keeps sending key-release messages while a key is kept in pressed state.
How to reproduce:

1. In a project, add a binding for any key in Config/input_bindings_ini, like this:
   SPACE: +MyKeyIsPressed
   SPACE: -MyKeyIsReleased
2. In code, register a MessageListener for the messages
3. Now when the game is run, press the key, eg SPACE but don't release it: you will receive the "MyKeyIsPressed" message once and infinite "MyKeyIsReleased" messages until the key is actually released, although the release message should only occur once when the key is actually released.

Hello,
When I want draw a text into game, its not working. Probably text transparent. How can I add color to text?

#include "stdafx.h"


int main(int argc, char* argv[])
{
    int windowWidth = 800;
    int windowHeight = 600;
    std::string windowName = "Pencere Ismi";
    bool antiAliasing = false;
    bool fullScreen = false;
    bool resizable = false;

    theWorld.Initialize(800,600,"Pencere Ismi");
    sysLog.Log("Game initialized");

    //adds the default grid so you can more easily place Actors
    theWorld.Add(new GridActor(), -1);
    sysLog.Log("Default grid added");

    //YOUR GAME SETUP CODE HERE
    RegisterFont("Resources/Fonts/Inconsolata.otf", 12, "Black12");
    sysLog.Log("Black font registered");
    DrawGameText("Tugay Torunok", "Black12", 50, 50, 45.0f);
    sysLog.Log("Text drawed");

    // do all your setup first, because this function won't return until you're exiting
    sysLog.Log("Game starting...");
    theWorld.StartGame();

    // any cleanup can go here
    sysLog.Log("Cleanup started...");
    theWorld.Destroy();
    sysLog.Log("Cleanup finished");

    return 0;
}

Downloaded Angel 2D 3.2, opened up GameJam.sln in a fully updated Visual Studio Community 2015 on Windows 10 x64 bit and attempted to build the IntroGame. Received the following errors:

I had to do the following things to get IntroGame to build and execute properly:

1. When opening the project for the first time I let Visual Studio update the compiler for the projects.
2. In the Angel project, Infrastructure/Common.h at line 41 is the #include for hash_map, I add this line above it:
   #define _SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS
3. Right click project _GLFW > Properties, in the new window I go to Configuration Properties > C/C++ > Code Generation and change Enable Function-Level Linking to Yes

At this point the build runs and the intro executes fine but there's still an error about not finding "stdafx.h" in Actor.cpp. At one point I was able to get rid of that but while reproducing my steps for this bug I can't seem to figure out what I did before. You can definitely get rid of it by adding an empty stdafx.h to the Angel project though.

I'm not a very experienced C++ dev so I don't know what side effects some of these changes might have. I'm just bringing this to somebody's attention so they can make the informed decision about what to do with these out-of-the-box errors.

How build game run on android? Can it now?

World::SetSideBlockers() assumes the camera has zero rotation. If the camera is rotated (e.g. if it is locked to a rotating Actor and theCamera._lockRotation == true), the side blockers move with respect to the field of view, often entering the visible area and affecting the physics simulation.

This occurs because the blockers take Camera::GetWorldMinVertex and ::GetWorldMaxVertex to be the bottom left and lower right corners of the view, respectively. This property is only true when the camera is axis-aligned.

Not a big issue, but probably worth documenting.

if(*it) {
( *it)->destroy()
}

In Intro Game the error WARNING: Can't add a null element to the World. Segmentation fault (core dumped) happens frequently especially once the file after "DemoScreenDefFile.cpp, demo_actors.lua" screen. Also in Client Game the message `OpenGL Error: invalid value' gets spamed out to console one time per second. Please take a look at this :)

I created an Actor Class and added to theWorld. But in scene, actor not showing.

// Game Manager's Init function
Character* character = new Character();
theWorld.Add(character);

#include "stdafx.h"
#include "Character.h"

Character::Character()
{
    SetPosition(-3.0f, 4.0f);
    SetDrawShape(ADS_Square);
    SetSprite("Resources/Images/character.png");
    SetSize(3.0f);
    SetName("Character");
    Tag("player, controllable");
}

class Character : public Actor {
public:
    Character();

        void Update(float dt);

        void Render();

private:
};

No Compile Error

Hello,
I want use

theWorld.SetGameManager(???);

How can I create a Game Manager. I think I must create gameManagerGame.h and gameManagerGame.cpp. Whats I write into to gameManagerGame.h and gameManagerGame.cpp. Any example? I can't understand at IntroGame folder.

Hello,
I created game manager and i testing Update Function. But in console log this message logging.

OpenGL Error: invalid value
OpenGL Error: invalid value
OpenGL Error: invalid value
[...]

What is problem?

Main.cpp

#include "stdafx.h"
#include "theGameName.h"


int main(int argc, char* argv[])
{
    int windowWidth = 800;
    int windowHeight = 600;
    std::string windowName = "Pencere Ismi";
    bool antiAliasing = false;
    bool fullScreen = false;
    bool resizable = false;

    theWorld.Initialize(800,600,"Pencere Ismi");
    sysLog.Log("Game initialized");

    //adds the default grid so you can more easily place Actors
    theWorld.Add(new GridActor(), -1);
    sysLog.Log("Default grid added");

    //YOUR GAME SETUP CODE HERE
    theWorld.SetGameManager(&theGameName);

    // do all your setup first, because this function won't return until you're exiting
    sysLog.Log("Game starting...");
    theWorld.StartGame();

    // any cleanup can go here
    sysLog.Log("Cleanup started...");
    theWorld.Destroy();
    sysLog.Log("Cleanup finished");

    return 0;
}

theGameName.h

#pragma once

class theGameName
{
public:
    virtual void Start();
    virtual void Update(float dt);
};

theGameName.cpp

#include "stdafx.h"
#include "theGameName.h"

void theGameName::Start()
{
    RegisterFont("Resources/Fonts/Inconsolata.otf", 12, "Black12");
    sysLog.Log("Black font registered");

    Actor *player = new Actor();
    player->SetPosition(0.0f, 0.0f);
    player->SetDrawShape(ADS_Square);
    player->LoadSpriteFrames("Resources/Images/skeletonfront_001.png");
    player->PlaySpriteAnimation(0.2f, SAT_Loop, 0, 4, "SkeletonFront");
    player->SetSize(2.0f);
    sysLog.Log("Player actor created");

    theWorld.Add(player);
    sysLog.Log("Player added to world");
}

void theGameName::Update(float dt)
{

}

I haven't looked at game engines in a while, so forgive me if this is not an actual issue. In the GridActor code, SetInterval just updates the _interval variable, but without recalculating points (a private function, so can't call outside) this doesn't really seem to do what it should be doing. Changing min and max coords calls RecalculatePoints, and so the does the constructor, which I understand I can just use that to start with but this seems like a break in functionality.

Hello! I was testing out Angel and I noticed the demos all look a bit pixelated on my retina MBP. Here's a screenshot (make sure you look at the full size):

In Message.h
///A templated class for delivering additional information with Messages
/**

• This class lets you define your own message types that carry data with
• them. For instance, if you wanted to create a Message that carried
• a world location with it:
• \code
• TypedMessage *m = new TypedMessage("SomethingHappenedHere", Vector2(-3, -2));
• \endcode
• This gets sent through the Switchboard as just a pointer to the base class,
• though, so your MessageReceivers will have to parse what it is from the
• Message::GetMessageType function and cast it appropriately from there.
  */

The Message::GetMessageType function isn't implemented or declared anywhere it seems. Maybe I'm missing something.

I'm doing my first steps with C++ and game development to build a simple prototype.

This would be more as a question because i'm not sure is an issue.

I've chosen Angel2D as framework to get some help from the beginning but I have problems to get it working with a simple Hello world! console message.

I've followed the installation instructions for Mac but it won't work properly.

My project structure is

/GamePrototype/test.cpp // the file I try to build
/GamePrototype/Angel    // Angel2D is inside this folder
/GamePrototype/Etc

If I try a file like this:

#include <iostream>
using namespace std;

int main() {
    cout << "Hello world!" << endl;
    return 0;
 }

Sublime Text opens it's console and shows Hello world! correctly.

If I just include Angel main file Angel.h to the file like this

#include "Angel/Angel.h"
#include <iostream>
using namespace std;

int main() {
    cout << "Hello world!" << endl;
    return 0;
}

It throws this error:

/Angel/Actors/../Infrastructure/../Util/../Infrastructure/Common.h:94:11:
fatal error: 'GLFW/glfw3.h' file not found
    #include <GLFW/glfw3.h>
                  ^

The file is probably located in /GamePrototype/Angel/Libraries/glfw-3.0.3/include/GLFW/glfw3.h

Probably it's just a base knowledge of C++ and how to build projects, what's wrong with the OpenGL library?

It seems like it's just trying to load the library in the wrong place, but I can't believe the release is broken.

Has anyone started developping networking stuff yet? If not, I'd start it with Raknet. http://www.jenkinssoftware.com/
It's free for non-commercial games on Windows, Mac, Linux, Android, Windows Phone 8, and IOS. See here: http://www.jenkinssoftware.com/pricing.html I think that fits the needs for game jams.
It also has a GitHub Repo: https://github.com/OculusVR/RakNet

My ideas are: basically get a functionality like in Unity3d. We will need something like a connection manager. We need an easy way to synchronize (physics-) actors. We need a way to call special functions on "the other side".

Any hints for how to do this? I've never done such a thing so help is appreciated.

Hi angel2d developer team.

I very like your framework and I want to write own game engine. I was looking classes of the engine and your codes looks like very clean. I can understand how the engine works. I know It's not easy and the project is amazing.

I hope you still update the engine? And do you think to add android option in the future?

Thank you.

Hi,

I have a different keyboard layout (german). Probably that is also the main reason, why I can't open the in-game console. It would be very helpful if the key to open the console was configurable.

(ubuntu build)