Sign in to follow this  
Followers 0
Joyal

OpenGL
Creating a simple 2d engine (C++), best way to create an Sprite class?

3 posts in this topic

Since MS announced that they are not give more support to XNA , for me was an opportunity to start to learn DirectX , so i wanted to learn DX11,

i was following this tutorials 

 

http://www.rastertek.com/tutdx11.html

 

i want to build a simple 2D engine while im learning with basic thing,like render an sprite based on a spritesheet, ,animate it, scale, rotation, flip image

 

I started creating some simple basic structure, 

- Engine Class, this hold the initialization of the Window basically

- RenderManager class, this hold all the DX stuff, initialize it, create the swapchain, store the device , etc

 

So now my next step is create the Sprite class , i wanted to create an method called "Quad2D" inside my RenderManager, so i can use it on my render method in my sprite class

 

//This is not actual code, is just oh i want to approach this
class Sprite{

public void Render(RenderManager *rm){
  
    rm->Quad2D(Texture,Position,Width,Height);

}
}

i have some experience with OpenGL and Directx9 , it was easy to approach this, i just need to create an Array with the vertex, send to the VertexBuffer, bind the Texture, and done, 

 

but because now DX10 and DX11 not used fixed pipeline, and you need create this with more advanced stuff (Shaders),

i stopped in here http://www.rastertek.com/dx11tut11.html , i can see how to render the image and everything, but i was thinking, do i need to create an separate Class just to render a Quad? if so, this is going to compile the shader everytime is used?, well one solution maybe is just declare an static atribute for the ps and vs to share the same compile shader

 

so i want to hear your suggestion, how do you manage your Sprite class? 

 

if it necessary, i can attach my source code, but it doesnt has too much, just open a window

 

Note: i want to know how to do it in DX11, please dont reply, (used DX9,OpenGL,DX10, etc..)

Edited by Joyal
0

Share this post


Link to post
Share on other sites

Create separate classes for Shaders, Vertex Buffers etc. 

 

 For example i have the following class for vertex shader:

class VertexShaderDX11
	{
	protected:

		ID3D11VertexShader*	m_pShader;
		InputAssemblerStateDX11*	m_pState;

	public:
		VertexShaderDX11()  { m_pState = new InputAssemblerStateDX11(); }
		~VertexShaderDX11() {	SAFE_RELEASE(m_pShader);
								SAFE_DELETE(m_pState); }

		ABOOL Create(BlobDX11 & shaderbuffer, INPUT_LAYOUT* layout, AUINT8 num,
										 AUINT16 topology);
		AVOID Set() const;
	};

 

Note that it has pointer to the InputAssembler structure (it stores information about Input Assembler stage as for vertex shader you have to have right input topology). 

 

 In your sprite class you can reference shader for rendering and bind it to the pipeline before you render your sprite. Don't recompile shader all the time! Compile it one time and then just have a pointer to an object of your shader class which stores compiled shader.  Multiple sprites can use single shader for rendering just having pointer to it.

Edited by DgekGD
1

Share this post


Link to post
Share on other sites

I'm somewhat curious how your Quad2D method is handling things under the hood. Is it buffering the sprites and then drawing them in all one big draw call, sorting them by texture, or does each call set the texture, vertex buffers, IA Layout, shaders, etc? If it is the latter then it is likely to not be all that efficient. You may want to look into mimicking the way SpriteBatch in XNA handles things. You tell it to Begin() and then you do a number of Draw() calls. When you are finished you say End(), which draws all the sprites in one go. This approach is generally more efficient.

 

As for me, I store all my sprites as points in a dynamic vertex buffer and expand them to quads in the Geometry shader. This makes managing the vertex buffers on the C side much easier.

1

Share this post


Link to post
Share on other sites

@DgekGD , i like your approach because i can use the same VS and PS in differents classes biggrin.png!

 

 

@Racoonacoon well right now i don`t have the implementation made of Quad2D on my current "Engine"(DX11), i wanted to ask before i do it because DX10-11 works different,  but i do have my DX9 version , 

 

void RenderManager::DrawQuad2D (CTexture* texture, Vector2 position, int w, int h)
{

	// position = [0] 
	//
	//  [0]------[2]
	//   |        |
	//   |        |
	//   |        |
	//  [1]------[3]
	
	Vector2 coord_text[4];
	coord_text[0].x = 0.f;	coord_text[0].y = 0.f;
	coord_text[1].x = 0.f;	coord_text[1].y = 1.f;
	coord_text[2].x = 1.f;	coord_text[2].y = 0.f;
	coord_text[3].x = 1.f;	coord_text[3].y = 1.f;
			
	unsigned short indices[6]={0,2,1,1,2,3};
	SCREEN_TEXTURE_VERTEX v[4] =
	{
			{ (float)position.x,	(float)position.y,	0.f,1.f, coord_text[0].x,	coord_text[0].y} //(x,y) sup_esq.
		,	{ (float)position.x,	(float)position.y+h,	0.f,1.f, coord_text[1].x,	coord_text[1].y} //(x,y) inf_esq.
		, 	{ (float)position.x+w,	(float)position.y,	0.f,1.f, coord_text[2].x,	coord_text[2].y} //(x,y) sup_dr.
		,	{ (float)position.x+w,	(float)position.y+h,	0.f,1.f, coord_text[3].x,	coord_text[3].y} //(x,y) inf_dr.
	};

	m_pD3DDevice->SetFVF( SCREEN_TEXTURE_VERTEX::getFlags() );
	m_pD3DDevice->SetTexture(0, texture->GetD3DXTexture() );
	m_pD3DDevice->DrawIndexedPrimitiveUP( D3DPT_TRIANGLELIST,0, 4, 2,indices,D3DFMT_INDEX16, v, sizeof( SCREEN_TEXTURE_VERTEX ) );
}

 

 

Well i based in your suggestion , i think i will do some sort of XNA's "SpriteBranch", and that class can be instantiated once, and be passed on the "Render" method,  instead of the "RenderManager", 

 

Thank for your greats advice 

Edited by Joyal
0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0

  • Similar Content

    • By recp
      Hi,
      I'm working on new asset importer (https://github.com/recp/assetkit) based on COLLADA specs, the question is not about COLLADA directly
      also I'm working on a new renderer to render (https://github.com/recp/libgk) imported document.
      In the future I'll spend more time on this renderer of course, currently rendering imported (implemented parts) is enough for me
      assetkit imports COLLADA document (it will support glTF too),
      importing scene, geometries, effects/materials, 2d textures and rendering them seems working
      My actual confusion is about shaders. COLLADA has COMMON profile and GLSL... profiles,
      GLSL profile provides shaders for effects so I don't need to wory about them just compile, link, group them before render

      The problem occours in COMMON profile because I need to write shaders,
      Actually I wrote them for basic matrials and another version for 2d texture
      I would like to create multiple program but I am not sure how to split this this shader into smaller ones,

      Basic material version (only colors):
      https://github.com/recp/libgk/blob/master/src/default/shader/gk_default.frag
      Texture version:
      https://gist.github.com/recp/b0368c74c35d9d6912f524624bfbf5a3
      I used subroutines to bind materials, actually I liked it,
      In scene graph every node can have different program, and it switches between them if parentNode->program != node->program
      (I'll do scene graph optimizations e.g.  view frustum culling, grouping shaders... later)

      I'm going to implement transparency but I'm considering to create separate shaders,
      because default shader is going to be branching hell
      I can't generate shader for every node because I don't know how many node can be exist, there is no limit.
      I don't know how to write a good uber-shader for different cases:

      Here material struct:
      struct Material { ColorOrTexture emission; ColorOrTexture ambient; ColorOrTexture specular; ColorOrTexture reflective; ColorOrTexture transparent; ColorOrTexture diffuse; float shininess; float reflectivEyety; float transparency; float indexOfRefraction; }; ColorOrTexture could be color or 2d texture, if there would be single colorOrTex then I could split into two programs,
      Also I'm going to implement transparency, I am not sure how many program that I needed

      I'm considering to maintain a few default shaders for COMMON profile,
      1-no-texture, 2-one of colorOrTexture contains texture, 3-........

      Any advices in general or about how to optimize/split (if I need) these shaders which I provied as link?
      What do you think the shaders I wrote, I would like to write them without branching if posible,
      I hope I don't need to write 50+ or 100+ shaders, and 100+ default programs

      PS: These default shaders should render any document, they are not specific, they are general purpose...
             I'm compiling and linking default shaders when app launched

      Thanks
    • By CircleOfLight97
      Hi guys,
      I would like to contribute to a game project as a developer (open source possibly). I have some experiences in C/C++ in game development (perso projects). I don't know either unreal or unity but I have some knowledges in opengl, glsl and shading theory as I had some courses at university regarding to that. I have some knowledges in maths and basic in physics. I know a little how to use blender to do modelling, texturing and simple game assets (no characters, no animation no skinning/rigging). I have no game preferences but I like aventure game, dungeon crawler, platformers, randomly generated things. I know these kind of projects involve a lot of time and I'd be really to work on it but if there are no cleary defined specific design goals/stories/gameplay mechanics I would like to not be part of it x) and I would rather prefer a smaller but well defined project to work on that a huge and not 'finishable' one.
      CircleOfLight97
    • By gamesthatcouldbeworse
      Hi, I finally released KILL COMMANDO on gamejolt for free. It is a retro-funsplatter-shooter with C64 style. Give it a try.
    • By phil67rpg

      void TimerFunction(int value) {  glutPostRedisplay();  glutTimerFunc(1000, TimerFunction, 1); } void drawScene() {  glClear(GL_COLOR_BUFFER_BIT);      drawScene_bug();  TimerFunction(1);  eraseScene_bug(); // drawScene_bug_two(); // eraseScene_bug_two(); drawScene_ship(); drawScene_bullet();  glutSwapBuffers(); }