Sign in to follow this  
chowarth

DX11 Sprite Rendering Position Problem.

Recommended Posts

chowarth    516

I've been trying to implement sprites and read through the RasterTek tutorial on rendering sprites. I got everything working fine but I didn't like the idea of using dynamic vertex buffers to make it possible to move a sprite, so I went about changing them to use a matrix instead.

 

I have come across a little problem with sprite positions.

 

I create a few sprites like so:

mpScene->AddSprite( "TestSprite1", "alpha.png", 0,    0,    100,    100 );
mpScene->AddSprite( "TestSprite2", "alpha.png", 100,    0,    100,    100 );
mpScene->AddSprite( "TestSprite3", "alpha.png", 0,      100,    100,    100 );

 

Now my assumption is that if I create a sprite at (0, 0) with dimensions of (100, 100), and then create another at (100, 0) with the same dimensions that the two sprites would be right next to each other, however they seem to be the full width of a sprite apart:

 

sprites_zpse3239e19.png

 

 

This is how I create my sprite buffers:

// Calculate screen space positions of the vertices
float left        = ( ( screenWidth * 0.5f ) * -1 ) + posX;
float right        = left + width;
float top        = ( screenHeight * 0.5f ) + posY;
float bottom    = top - height;

// Populate vertices.
vertices[0].Pos = XMFLOAT3( left, top, 1.0f );
vertices[0].Tex = XMFLOAT2( 0.0f, 0.0f );

vertices[1].Pos = XMFLOAT3( right, top, 1.0f );
vertices[1].Tex = XMFLOAT2( 1.0f, 0.0f );

vertices[2].Pos = XMFLOAT3( right, bottom, 1.0f );
vertices[2].Tex = XMFLOAT2( 1.0f, 1.0f );

vertices[3].Pos = XMFLOAT3( left, bottom, 1.0f );
vertices[3].Tex = XMFLOAT2( 0.0f, 1.0f );

// Create indices array.
indices = new USHORT[numIndices];
indices[0] = 0;    //
indices[1] = 1;    // Triangle 1
indices[2] = 2;    //___________
indices[3] = 0;    //
indices[4] = 2;    // Triangle 2
indices[5] = 3;    //

 

and how I create the sprite matrix:

XMMATRIX p    = XMMatrixTranslation( mPosition.x, mPosition.y, mPosition.z );
XMMATRIX r    = XMMatrixRotationZ( mRotation );
XMMATRIX s    = XMMatrixScaling( mScale.x, mScale.y, 1.0f );

XMStoreFloat4x4( &mMatrix, p * r * s );
 

 

and the rendering of the sprites:

// Disable depth testing when drawing sprite objects.
pDevice->SetDepthStencilState( mpDepthDisabledState );

mpSpriteFX->SetMatrix( "gViewProjMatrix", pCamera->GetOrthoMatrix() );
pDevice->SetInputLayout( mpSpriteFX->GetInputLayout() );

CSprite* pSprite = NULL;
pSpriteList->BeginEnumeration();

while( ( pSprite = pSpriteList->EnumAsset() ) != 0 )
{
    CTexture* pTexture = pTextureList->GetAsset( pSprite->GetTextureUID() );
    mpSpriteFX->SetSRV( "dTexture", pTexture->GetSRV() );

    pDevice->SetVertexIndexBuffer( sizeof( SpriteVertex ), pSprite->GetVB(), pSprite->GetIB() );

    mpSpriteFX->SetMatrix( "gWorldMatrix", pSprite->GetMatrix() );

    UINT numPasses = mpSpriteFX->GetNumPasses();
    for( UINT pass = 0; pass < numPasses; pass++ )
    {
        pDevice->ApplyTechPass( mpSpriteFX->GetTechnique(), pass );

        pDevice->DrawIndexed( mNumIndices, 0, 0 );
    }
}
pSpriteList->EndEnumeration();
    
// Re-enable depth testing for drawing non-sprite objects.
pDevice->SetDepthStencilState( NULL );

 

I'm just wondering if there's something I've done wrong or an explanation as to why the sprites would be positioned the full width of a sprite apart instead of next to each other as I would expect.

 

Thanks in advance.

 

Edit:

Appears the image wasn't working :( Fixed (I hope).

Edited by chowarth

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  

  • Partner Spotlight

  • Similar Content

    • By noodleBowl
      I was thinking about how to render multiple objects. Things like sprites, truck models, plane models, boats models, etc. And I'm not too sure about this process
      Let's say I have a vector of Models objects
      class Model {  Matrix4 modelMat;  VertexData vertices;  Texture texture;  Shader shader; }; Since each model has is own model matrix, as all models should, does this mean I now need to have 1 draw call per model?
      Because each model that needs to be drawn could change the MVP matrix used by the bound vertex shader. Meaning I have to keep updating/mapping the constant buffer my MVP matrix is stored in, which is used by the vertex shader
      Am I thinking about all of this wrong? Isn't this horribly inefficient?
    • By RubenRS
      How do i open an image to use it as Texture2D information without D3DX11CreateShaderResourceViewFromFile? And how it works for different formats like (JPG, PNG, BMP, DDS,  etc.)?
      I have an (512 x 512) image with font letters, also i have the position and texcoord of every letter. The main idea is that i want to obtain the image pixel info, use the position and texcoords to create a new texture with one letter and render it. Or am I wrong in something?
    • By thmfrnk
      Hey,
      I found a very interesting blog post here: https://bartwronski.com/2017/04/13/cull-that-cone/
      However, I didn't really got how to use his "TestConeVsSphere" test in 3D (last piece of code on his post). I have the frustumCorners of a 2D Tile cell in ViewSpace and my 3D Cone Origin and Direction, so where to place the "testSphere"? I thought about to also move the Cone into viewspace and put the sphere to the Center of the Cell with the radius of half-cellsize, however what about depth? A sphere does not have inf depth?
      I am missing anything? Any Ideas?
      Thx, Thomas
    • By Modymek
      hi all
      I want to enable and disable shader in MPCH Media player Classic
      the MPCH have shader option using HLSL shaders
      I want the shader to read each file extension before it plays the file
      so if the video file name is video.GR.Mp4 it will play it in Grayscale shader 
      if it is not and standard file name Video.Mp4 without GR. unique extension so it plays standard without shader or end the shader
      here is the shader I have for grayscale
      // $MinimumShaderProfile: ps_2_0
      sampler s0 : register(s0);
      float4 main(float2 tex : TEXCOORD0) : COLOR {
          float c0 = dot(tex2D(s0, tex), float4(0.299, 0.587, 0.114, 0));
          return c0;
      }
       
      I want to add if or block stantement or bloean to detect file name before it call the shader in order to go to the procedure or disable it or goto end direct without it
       
      any thoughts or help
    • By noodleBowl
      I've gotten to part in my DirectX 11 project where I need to pass the MVP matrices to my vertex shader. And I'm a little lost when it comes to the use of the constant buffer with the vertex shader
      I understand I need to set up the constant buffer just like any other buffer:
      1. Create a buffer description with the D3D11_BIND_CONSTANT_BUFFER flag 2. Map my matrix data into the constant buffer 3. Use VSSetConstantBuffers to actually use the buffer But I get lost at the VertexShader part, how does my vertex shader know to use this constant buffer when we get to the shader side of things
      In the example I'm following I see they have this as their vertex shader, but I don't understand how the shader knows to use the MatrixBuffer cbuffer. They just use the members directly. What if there was multiple cbuffer declarations like the Microsoft documentation says you could have?
      //Inside vertex shader cbuffer MatrixBuffer { matrix worldMatrix; matrix viewMatrix; matrix projectionMatrix; }; struct VertexInputType { float4 position : POSITION; float4 color : COLOR; }; struct PixelInputType { float4 position : SV_POSITION; float4 color : COLOR; }; PixelInputType ColorVertexShader(VertexInputType input) { PixelInputType output; // Change the position vector to be 4 units for proper matrix calculations. input.position.w = 1.0f; // Calculate the position of the vertex against the world, view, and projection matrices. output.position = mul(input.position, worldMatrix); output.position = mul(output.position, viewMatrix); output.position = mul(output.position, projectionMatrix); // Store the input color for the pixel shader to use. output.color = input.color; return output; }  
  • Popular Now