Hey mate so there are a few ways to draw on screen, you can draw a full screen triangle and do some fancy shader math or you can render a full quad.
Ill show you how to do both.
Full Screen Quad Render:
This is the full quad renderer class, its a bit of setup but it works well, I pulled it out of my code base so you will have to remove all my stuff.
Public Class QuadRenderer Private _vertexBuffer As VertexPositionTexture() = Nothing Private _indexBuffer As Integer() = Nothing Private instdata As DataStream Private vertexBuffer As Buffer Private indexBuffer As Buffer Private QuadInputlayout As InputLayout Private QuadVertexBinding As VertexBufferBinding() Public Sub New(_device As LowLevelDevice, ShaderInput As ShaderBytecode) 'setting up the indexbuffer _indexBuffer = New Integer() {0, 3, 2, 0, 1, 3} instdata = New DataStream(_indexBuffer.Count * 4, True, True) instdata.WriteRange(_indexBuffer, 0, _indexBuffer.Count) instdata.Position = 0 indexBuffer = _device.CreateBuffer(instdata, _indexBuffer.Count * 4, ResourceUsage.Immutable, BindFlags.IndexBuffer, CpuAccessFlags.None, ResourceOptionFlags.None, 0) 'setting up the quad verts _vertexBuffer = New VertexPositionTexture(3) {} _vertexBuffer(0) = New VertexPositionTexture(New Vector3(-1.0!, 1.0!, 0!), New Vector2(0!, 0!)) _vertexBuffer(1) = New VertexPositionTexture(New Vector3(1.0!, 1.0!, 0!), New Vector2(1.0!, 0!)) _vertexBuffer(2) = New VertexPositionTexture(New Vector3(-1.0!, -1.0!, 0!), New Vector2(0!, 1.0!)) _vertexBuffer(3) = New VertexPositionTexture(New Vector3(1.0!, -1.0!, 0!), New Vector2(1.0!, 1.0!)) 'setting up the vertexbuffer instdata = New DataStream(_vertexBuffer.Count * VertexPositionTexture.Stride, True, True) instdata.WriteRange(_vertexBuffer, 0, _vertexBuffer.Count) instdata.Position = 0 vertexBuffer = _device.CreateBuffer(instdata, New BufferDescription(_vertexBuffer.Count * VertexPositionTexture.Stride, ResourceUsage.Immutable, BindFlags.VertexBuffer, 0, 0, 0)) QuadVertexBinding = New VertexBufferBinding() {New VertexBufferBinding(vertexBuffer, VertexPositionTexture.Stride, 0)} 'setting up the inputlayout Dim PosColor As InputElement() = {New InputElement("POSITION", 0, Format.R32G32B32_Float, 0, 0, InputClassification.PerVertexData, 0), New InputElement("TEXCOORD", 0, Format.R32G32_Float, InputElement.AppendAligned, 0, InputClassification.PerVertexData, 0)} QuadInputlayout = _device.CreateInputLayout(ShaderInput, PosColor) End Sub Public Sub RenderQuad(ByRef _Context As DeviceContext,srv as shaderresourceview) 'setting renderstate _Context.PixelShader.SetShaderResource(0, srv)' srv= the texture you want to draw _Context.InputAssembler.InputLayout = QuadInputlayout _Context.InputAssembler.PrimitiveTopology = PrimitiveTopology.TriangleList _Context.InputAssembler.SetVertexBuffers(0, QuadVertexBinding) _Context.InputAssembler.SetIndexBuffer(indexBuffer, Format.R32_UInt, 0) _Context.DrawIndexed(6, 0, 0) End Sub End Class
_device.CreateInputLayout is a custom inputlayout builder so you just pass it a vertex shader and it gives you the correct inputlay but you will have to start a new question for that.
HLSL: This is the shader for the full screen quad.
Texture2D colorMap; //DeviceContext.PixelShader.SetShaderResource(0, srv) sets this on the cpu sampler colorSampler = sampler_state { AddressU = Clamp; AddressV = Clamp; Filter = MIN_MAG_MIP_POINT; }; struct VertexInput { float3 Position : POSITION0; float2 TexCoord : TEXCOORD0; }; VertexShaderOutput VSQuad2(VertexInput input) { VertexShaderOutput result; result.Position = float4(input.Position,1); //reading vertex data from the stream result.TexCoord = input.TexCoord; return result; } PixelShaderOutput PShader(VertexShaderOutput input) { PixelShaderOutput output = (PixelShaderOutput)0; float4 Color= colorMap.Sample(colorSampler , input.TexCoord);//the texture you want to draw return output; }
Full Screen Triangle:
The cool thing about this one is that there is no CPU side set up, the DX runtime will generate the vertex data for you.
Use this bit of code to draw the full screen triangle.
DeviceContext.InputAssembler.PrimitiveTopology = PrimitiveTopology.TriangleList DeviceContext.PixelShader.SetShaderResource(0, srv)' srv= the texture you want to draw DeviceContext.InputAssembler.SetVertexBuffers(Nothing) DeviceContext.InputAssembler.SetIndexBuffer(Nothing, Nothing, Nothing) DeviceContext.Rasterizer.State = Nothing DeviceContext.Draw(3, 0)
HLSL:
This is where the magic happens, you take your 3 verts and then position them in a way that covers the whole view port.
Texture2D colorMap; //DeviceContext.PixelShader.SetShaderResource(0, srv) sets this on the cpu sampler colorSampler = sampler_state { AddressU = Clamp; AddressV = Clamp; Filter = MIN_MAG_MIP_POINT; }; struct VertexShaderOutput { float4 Position : SV_Position; float2 TexCoord : TEXCOORD0; }; struct PixelShaderOutput { float4 Color : SV_Target0; }; // outputs a full screen triangle with screen-space coordinates // input: three empty vertices VertexShaderOutput VSQuad( uint vertexID : SV_VertexID ) { VertexShaderOutput result; result.TexCoord = float2((vertexID << 1) & 2, vertexID & 2); result.Position = float4(result.TexCoord * float2(2.0f, -2.0f) + float2(-1.0f, 1.0f), 0.0f, 1.0f); // compute the position data return result; } PixelShaderOutput PShader(VertexShaderOutput input) { PixelShaderOutput output = (PixelShaderOutput)1; float4 Color = colorMap.Sample(colorSampler, input.TexCoord); //the texture you want to draw output.Color =Color; return output; } technique11 Render { pass P0 { SetVertexShader( CompileShader( vs_5_0, VSQuad() ) ); SetPixelShader( CompileShader( ps_5_0, PShader() ) ); } }
I just had a look at the other question you asked and I need to say that the guy who wrote the answer there explains of the full screen triangle stuff works much better.
