23 replies to this topic

[eXtreme]

Okay guys, i know this question sound sucks, but i am new in Game Engine programming, so is there any difference, that i should know, before i begin creating a game engine?

[MJeannig]

There is no real difference. OpenGL has a cleaner syntax. So it may look easier for the beginner. Doing complex thing require to use extensions.
DirectX has a crappy COM-like syntax and ugly initialization but once you get used to it the two library are similar.
Everything is 3D and algorithms after all...

[Axel]

Quote

OpenGL has a cleaner syntax.

This is highly subjective aswell. For C++ coders the OOP style of Direct3D is pretty familiar and not "ugly".

[Ed Mack]

They are two apis that do the same thing. One is more portable, that's about it.

[TheNut]

Does a painter require a specific brush to paint? Does an artist require a specific pen to draw?

Games and graphics share a very basic commonality. They all operate on the basis of geometry and material properties. Regardless of the API you chose, it should not affect the design and operation of your engine, just like using a 10 cent pen from Staples won’t affect the quality of an artist’s drawing. Learn how to use data structures and abstraction to organize yourself an engine capable of maintaining polygons and materials. Combine the two later into your renderer component to actually draw the objects on the screen. With this approach, you open your engine up to countless other ways to render your scenes. Software, ray tracing, Direct3D, OpenGL, who cares. They all do the same thing in the end.

[geon]

You could also use EaseWrapper and forget about the whole gl/dx issue.

[karligula]

Just try each one for a week and then use whichever one floats your boat highest...

[kusma]

i second karigula's suggestion. both apis expose more or less the same functionality. try both out and decide for yourself.

[mysticman]

D3D is a pig to set-up (while OpenGL is a piece of cake):no:

[Axel]

Direct3D is not a pig to setup since DirectX 8. Its about the same amount of code you would have to setup your OpenGL context.

[SamuraiCrow]

I recommend OpenGL due to its portablilty. As for setting up an OpenGL context, use SDL or GLFW to set up the context. Otherwise you're still writing Windows-specific code and it won't be as portable. (Need I mention that I don't develop for Windows if I can avoid it?)

[kusma]

d3d is more pain to setup?

IDirect3D9 *direct3d = Direct3DCreate9(D3D_SDK_VERSION);

HWND window = CreateWindowEx(0, "static", "BIG", WS_POPUP | WS_VISIBLE, 0, 0, WIDTH, HEIGHT, 0, 0, GetModuleHandle(0), 0);

static D3DPRESENT_PARAMETERS present_parameters = { WIDTH, HEIGHT, D3DFMT_X8R8G8B8, 3, D3DMULTISAMPLE_NONE, 0, D3DSWAPEFFECT_DISCARD, 0, FALSE, 1, D3DFMT_D24S8, 0, D3DPRESENT_RATE_DEFAULT, 0 };

direct3d->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, window, D3DCREATE_HARDWARE_VERTEXPROCESSING, &present_parameters, &device);

versus

DEVMODE devmode = { {0}, 0, 0, sizeof(DEVMODE), 0, DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT, {0}, 0,0,0,0,0,{0},0, BPP, WIDTH, HEIGHT, 0, 0 };

ChangeDisplaySettings((LPDEVMODE)&devmode, CDS_FULLSCREEN);

ShowCursor(FALSE);

win = CreateWindowEx(0, "static", "static", WS_POPUP | WS_VISIBLE, 0, 0, WIDTH, HEIGHT, 0, 0, GetModuleHandle(0), 0);

hdc = GetDC(win);

GLuint pixelformat = ChoosePixelFormat(hdc, &pfd);

SetPixelFormat(hdc, pixelformat, &pfd);

hrc = wglCreateContext(hdc);

wglMakeCurrent(hdc, hrc);

...

[kusma]

setup-code should in general not count when choosing api anyway, since it's code you write once. general usage of the api is more relevant.

[CobraLionz]

Forgive the children who are still on nehe tutorial #3

[mysticman]

kusma said:

d3d is more pain to setup?

IDirect3D9 *direct3d = Direct3DCreate9(D3D_SDK_VERSION);

HWND window = CreateWindowEx(0, "static", "BIG", WS_POPUP | WS_VISIBLE, 0, 0, WIDTH, HEIGHT, 0, 0, GetModuleHandle(0), 0);

static D3DPRESENT_PARAMETERS present_parameters = { WIDTH, HEIGHT, D3DFMT_X8R8G8B8, 3, D3DMULTISAMPLE_NONE, 0, D3DSWAPEFFECT_DISCARD, 0, FALSE, 1, D3DFMT_D24S8, 0, D3DPRESENT_RATE_DEFAULT, 0 };

direct3d->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, window, D3DCREATE_HARDWARE_VERTEXPROCESSING, &present_parameters, &device);

versus

DEVMODE devmode = { {0}, 0, 0, sizeof(DEVMODE), 0, DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT, {0}, 0,0,0,0,0,{0},0, BPP, WIDTH, HEIGHT, 0, 0 };

ChangeDisplaySettings((LPDEVMODE)&devmode, CDS_FULLSCREEN);

ShowCursor(FALSE);

win = CreateWindowEx(0, "static", "static", WS_POPUP | WS_VISIBLE, 0, 0, WIDTH, HEIGHT, 0, 0, GetModuleHandle(0), 0);

hdc = GetDC(win);

GLuint pixelformat = ChoosePixelFormat(hdc, &pfd);

SetPixelFormat(hdc, pixelformat, &pfd);

hrc = wglCreateContext(hdc);

wglMakeCurrent(hdc, hrc);

...

I don't see an instruction in OpenGL in both the codes. This is everything code Windoz:closedeye

I with the setup don't intend whether to open a window but as to execute the rendering of a scene....:wub:

[baldurk]

If anyone has anything useful to say to the OP, feel free. Otherwise, stop beating a horse that died about 4 years ago. I won't say there aren't differences between the APIs, because there are, but there's no point flaming each other about it.

[SamuraiCrow]

Hear here!

Put simply, if you ever want your code to run on a Mac on Linux (or anything other than Windows or XBox series) use OpenGL.

[kusma]

mysticman said:

I don't see an instruction in OpenGL in both the codes. This is everything code Windoz:closedeye

I with the setup don't intend whether to open a window but as to execute the rendering of a scene....:wub:

Well, that kind of code is mostly just stuff like glDrawElements() versus device->DrawIndexedPrimitives(). this is simple semantics, it is NOT where you end up spending your actual development-time.

SamuraiCode: If you're serious about portability, you don't lock your engine to one API. And in either case, the biggest issue when porting a game to another (real-world) platform is tuning assets.

[daktaris]

SamuraiCrow said:

Hear here!

Put simply, if you ever want your code to run on a Mac on Linux (or anything other than Windows or XBox series) use OpenGL.

odd...my Unreal-based Xbox/PC game (therefore D3D) that was released last year also made it on Macs as well. Must have been emulated...

Sarcasm aside...Aspyr did the porting and they have this down to a science. Within 3 weeks they had it running on Linux and Macs including translating vertex and pixel shaders into vertex and fragment programs.

Take the advice of everyone who reiterated that it's a non-issue. Pick one and go with it. My criteria forselection is support/updates/sample code. Remember your thought process because it will serve you again once you have to pick a high level shading language .

[Axel]

Doesn't Unreal have an OpenGL backend anyway?