FNA-VSCode-Template/project_name/ImGui/ImGuiRenderer.cs
2019-02-14 17:34:19 -08:00

389 lines
13 KiB
C#

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Nez;
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
namespace ImGuiNET
{
/// <summary>
/// ImGui renderer for use with XNA-likes (FNA and MonoGame)
/// </summary>
public class ImGuiRenderer
{
// Graphics
BasicEffect _effect;
RasterizerState _rasterizerState;
readonly VertexDeclaration _vertexDeclaration;
readonly int _vertexDeclarationSize;
byte[] _vertexData;
VertexBuffer _vertexBuffer;
int _vertexBufferSize;
byte[] _indexData;
IndexBuffer _indexBuffer;
int _indexBufferSize;
// Textures
Dictionary<IntPtr, Texture2D> _loadedTextures;
int _textureId;
IntPtr? _fontTextureId;
// Input
int _scrollWheelValue;
List<int> _keys = new List<int>();
public ImGuiRenderer( Game game )
{
unsafe { _vertexDeclarationSize = sizeof( ImDrawVert ); }
_vertexDeclaration = new VertexDeclaration(
_vertexDeclarationSize,
// Position
new VertexElement( 0, VertexElementFormat.Vector2, VertexElementUsage.Position, 0 ),
// UV
new VertexElement( 8, VertexElementFormat.Vector2, VertexElementUsage.TextureCoordinate, 0 ),
// Color
new VertexElement( 16, VertexElementFormat.Color, VertexElementUsage.Color, 0 )
);
var context = ImGui.CreateContext();
ImGui.SetCurrentContext( context );
_loadedTextures = new Dictionary<IntPtr, Texture2D>();
_rasterizerState = new RasterizerState()
{
CullMode = CullMode.None,
DepthBias = 0,
FillMode = FillMode.Solid,
MultiSampleAntiAlias = false,
ScissorTestEnable = true,
SlopeScaleDepthBias = 0
};
setupInput();
}
#region ImGuiRenderer
/// <summary>
/// Creates a texture and loads the font data from ImGui. Should be called when the <see cref="GraphicsDevice" /> is initialized but before any rendering is done
/// </summary>
public unsafe void rebuildFontAtlas()
{
// Get font texture from ImGui
var io = ImGui.GetIO();
io.Fonts.GetTexDataAsRGBA32( out byte* pixelData, out int width, out int height, out int bytesPerPixel );
// Copy the data to a managed array
var pixels = new byte[width * height * bytesPerPixel];
Marshal.Copy( new IntPtr( pixelData ), pixels, 0, pixels.Length );
// Create and register the texture as an XNA texture
var tex2d = new Texture2D( Core.graphicsDevice, width, height, false, SurfaceFormat.Color );
tex2d.SetData( pixels );
// Should a texture already have been built previously, unbind it first so it can be deallocated
if( _fontTextureId.HasValue )
unbindTexture( _fontTextureId.Value );
// Bind the new texture to an ImGui-friendly id
_fontTextureId = bindTexture( tex2d );
// Let ImGui know where to find the texture
io.Fonts.SetTexID( _fontTextureId.Value );
io.Fonts.ClearTexData(); // Clears CPU side texture data
}
/// <summary>
/// Creates a pointer to a texture, which can be passed through ImGui calls such as <see cref="ImGui.Image" />. That pointer is then used by ImGui to let us know what texture to draw
/// </summary>
public IntPtr bindTexture( Texture2D texture )
{
var id = new IntPtr( _textureId++ );
_loadedTextures.Add( id, texture );
return id;
}
/// <summary>
/// Removes a previously created texture pointer, releasing its reference and allowing it to be deallocated
/// </summary>
public void unbindTexture( IntPtr textureId )
{
_loadedTextures.Remove( textureId );
}
/// <summary>
/// Sets up ImGui for a new frame, should be called at frame start
/// </summary>
public void beforeLayout( float deltaTime )
{
ImGui.GetIO().DeltaTime = deltaTime;
updateInput();
ImGui.NewFrame();
}
/// <summary>
/// Asks ImGui for the generated geometry data and sends it to the graphics pipeline, should be called after the UI is drawn using ImGui.** calls
/// </summary>
public void afterLayout()
{
ImGui.Render();
unsafe { renderDrawData( ImGui.GetDrawData() ); }
}
#endregion ImGuiRenderer
#region Setup & Update
/// <summary>
/// Maps ImGui keys to XNA keys. We use this later on to tell ImGui what keys were pressed
/// </summary>
void setupInput()
{
var io = ImGui.GetIO();
_keys.Add( io.KeyMap[(int)ImGuiKey.Tab] = (int)Keys.Tab );
_keys.Add( io.KeyMap[(int)ImGuiKey.LeftArrow] = (int)Keys.Left );
_keys.Add( io.KeyMap[(int)ImGuiKey.RightArrow] = (int)Keys.Right );
_keys.Add( io.KeyMap[(int)ImGuiKey.UpArrow] = (int)Keys.Up );
_keys.Add( io.KeyMap[(int)ImGuiKey.DownArrow] = (int)Keys.Down );
_keys.Add( io.KeyMap[(int)ImGuiKey.PageUp] = (int)Keys.PageUp );
_keys.Add( io.KeyMap[(int)ImGuiKey.PageDown] = (int)Keys.PageDown );
_keys.Add( io.KeyMap[(int)ImGuiKey.Home] = (int)Keys.Home );
_keys.Add( io.KeyMap[(int)ImGuiKey.End] = (int)Keys.End );
_keys.Add( io.KeyMap[(int)ImGuiKey.Delete] = (int)Keys.Delete );
_keys.Add( io.KeyMap[(int)ImGuiKey.Backspace] = (int)Keys.Back );
_keys.Add( io.KeyMap[(int)ImGuiKey.Enter] = (int)Keys.Enter );
_keys.Add( io.KeyMap[(int)ImGuiKey.Escape] = (int)Keys.Escape );
_keys.Add( io.KeyMap[(int)ImGuiKey.A] = (int)Keys.A );
_keys.Add( io.KeyMap[(int)ImGuiKey.C] = (int)Keys.C );
_keys.Add( io.KeyMap[(int)ImGuiKey.V] = (int)Keys.V );
_keys.Add( io.KeyMap[(int)ImGuiKey.X] = (int)Keys.X );
_keys.Add( io.KeyMap[(int)ImGuiKey.Y] = (int)Keys.Y );
_keys.Add( io.KeyMap[(int)ImGuiKey.Z] = (int)Keys.Z );
// MonoGame-specific //////////////////////
// _game.Window.TextInput += (s, a) =>
// {
// if (a.Character == '\t') return;
// io.AddInputCharacter(a.Character);
// };
///////////////////////////////////////////
// FNA-specific ///////////////////////////
TextInputEXT.TextInput += c =>
{
if( c == '\t' ) return;
ImGui.GetIO().AddInputCharacter( c );
};
///////////////////////////////////////////
ImGui.GetIO().Fonts.AddFontDefault();
}
/// <summary>
/// Updates the <see cref="Effect" /> to the current matrices and texture
/// </summary>
Effect updateEffect( Texture2D texture )
{
_effect = _effect ?? new BasicEffect( Core.graphicsDevice );
var io = ImGui.GetIO();
// MonoGame-specific //////////////////////
//var offset = .5f;
///////////////////////////////////////////
// FNA-specific ///////////////////////////
var offset = 0f;
///////////////////////////////////////////
_effect.World = Matrix.Identity;
_effect.View = Matrix.Identity;
_effect.Projection = Matrix.CreateOrthographicOffCenter( offset, io.DisplaySize.X + offset, io.DisplaySize.Y + offset, offset, -1f, 1f );
_effect.TextureEnabled = true;
_effect.Texture = texture;
_effect.VertexColorEnabled = true;
return _effect;
}
/// <summary>
/// Sends XNA input state to ImGui
/// </summary>
void updateInput()
{
var io = ImGui.GetIO();
var mouse = Mouse.GetState();
var keyboard = Keyboard.GetState();
for( int i = 0; i < _keys.Count; i++ )
{
io.KeysDown[_keys[i]] = keyboard.IsKeyDown( (Keys)_keys[i] );
}
io.KeyShift = keyboard.IsKeyDown( Keys.LeftShift ) || keyboard.IsKeyDown( Keys.RightShift );
io.KeyCtrl = keyboard.IsKeyDown( Keys.LeftControl ) || keyboard.IsKeyDown( Keys.RightControl );
io.KeyAlt = keyboard.IsKeyDown( Keys.LeftAlt ) || keyboard.IsKeyDown( Keys.RightAlt );
io.KeySuper = keyboard.IsKeyDown( Keys.LeftWindows ) || keyboard.IsKeyDown( Keys.RightWindows );
io.DisplaySize = new System.Numerics.Vector2( Core.graphicsDevice.PresentationParameters.BackBufferWidth, Core.graphicsDevice.PresentationParameters.BackBufferHeight );
io.DisplayFramebufferScale = new System.Numerics.Vector2( 1f, 1f );
io.MousePos = new System.Numerics.Vector2( mouse.X, mouse.Y );
io.MouseDown[0] = mouse.LeftButton == ButtonState.Pressed;
io.MouseDown[1] = mouse.RightButton == ButtonState.Pressed;
io.MouseDown[2] = mouse.MiddleButton == ButtonState.Pressed;
var scrollDelta = mouse.ScrollWheelValue - _scrollWheelValue;
io.MouseWheel = scrollDelta > 0 ? 1 : scrollDelta < 0 ? -1 : 0;
_scrollWheelValue = mouse.ScrollWheelValue;
}
#endregion Setup & Update
#region Internals
/// <summary>
/// Gets the geometry as set up by ImGui and sends it to the graphics device
/// </summary>
void renderDrawData( ImDrawDataPtr drawData )
{
// Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers
var lastViewport = Core.graphicsDevice.Viewport;
var lastScissorBox = Core.graphicsDevice.ScissorRectangle;
Core.graphicsDevice.BlendFactor = Color.White;
Core.graphicsDevice.BlendState = BlendState.NonPremultiplied;
Core.graphicsDevice.RasterizerState = _rasterizerState;
Core.graphicsDevice.DepthStencilState = DepthStencilState.DepthRead;
// Handle cases of screen coordinates != from framebuffer coordinates (e.g. retina displays)
drawData.ScaleClipRects( ImGui.GetIO().DisplayFramebufferScale );
// Setup projection
Core.graphicsDevice.Viewport = new Viewport( 0, 0, Core.graphicsDevice.PresentationParameters.BackBufferWidth, Core.graphicsDevice.PresentationParameters.BackBufferHeight );
updateBuffers( drawData );
renderCommandLists( drawData );
// Restore modified state
Core.graphicsDevice.Viewport = lastViewport;
Core.graphicsDevice.ScissorRectangle = lastScissorBox;
}
unsafe void updateBuffers( ImDrawDataPtr drawData )
{
if( drawData.TotalVtxCount == 0 )
{
return;
}
// Expand buffers if we need more room
if( drawData.TotalVtxCount > _vertexBufferSize )
{
_vertexBuffer?.Dispose();
_vertexBufferSize = (int)( drawData.TotalVtxCount * 1.5f );
_vertexBuffer = new VertexBuffer( Core.graphicsDevice, _vertexDeclaration, _vertexBufferSize, BufferUsage.None );
_vertexData = new byte[_vertexBufferSize * _vertexDeclarationSize];
}
if( drawData.TotalIdxCount > _indexBufferSize )
{
_indexBuffer?.Dispose();
_indexBufferSize = (int)( drawData.TotalIdxCount * 1.5f );
_indexBuffer = new IndexBuffer( Core.graphicsDevice, IndexElementSize.SixteenBits, _indexBufferSize, BufferUsage.None );
_indexData = new byte[_indexBufferSize * sizeof( ushort )];
}
// Copy ImGui's vertices and indices to a set of managed byte arrays
int vtxOffset = 0;
int idxOffset = 0;
for( var n = 0; n < drawData.CmdListsCount; n++ )
{
var cmdList = drawData.CmdListsRange[n];
fixed ( void* vtxDstPtr = &_vertexData[vtxOffset * _vertexDeclarationSize] )
fixed ( void* idxDstPtr = &_indexData[idxOffset * sizeof( ushort )] )
{
Buffer.MemoryCopy( (void*)cmdList.VtxBuffer.Data, vtxDstPtr, _vertexData.Length, cmdList.VtxBuffer.Size * _vertexDeclarationSize );
Buffer.MemoryCopy( (void*)cmdList.IdxBuffer.Data, idxDstPtr, _indexData.Length, cmdList.IdxBuffer.Size * sizeof( ushort ) );
}
vtxOffset += cmdList.VtxBuffer.Size;
idxOffset += cmdList.IdxBuffer.Size;
}
// Copy the managed byte arrays to the gpu vertex- and index buffers
_vertexBuffer.SetData( _vertexData, 0, drawData.TotalVtxCount * _vertexDeclarationSize );
_indexBuffer.SetData( _indexData, 0, drawData.TotalIdxCount * sizeof( ushort ) );
}
unsafe void renderCommandLists( ImDrawDataPtr drawData )
{
Core.graphicsDevice.SetVertexBuffer( _vertexBuffer );
Core.graphicsDevice.Indices = _indexBuffer;
int vtxOffset = 0;
int idxOffset = 0;
for( int n = 0; n < drawData.CmdListsCount; n++ )
{
var cmdList = drawData.CmdListsRange[n];
for( int cmdi = 0; cmdi < cmdList.CmdBuffer.Size; cmdi++ )
{
var drawCmd = cmdList.CmdBuffer[cmdi];
if( !_loadedTextures.ContainsKey( drawCmd.TextureId ) )
{
throw new InvalidOperationException( $"Could not find a texture with id '{drawCmd.TextureId}', please check your bindings" );
}
Core.graphicsDevice.ScissorRectangle = new Rectangle(
(int)drawCmd.ClipRect.X,
(int)drawCmd.ClipRect.Y,
(int)( drawCmd.ClipRect.Z - drawCmd.ClipRect.X ),
(int)( drawCmd.ClipRect.W - drawCmd.ClipRect.Y )
);
var effect = updateEffect( _loadedTextures[drawCmd.TextureId] );
foreach( var pass in effect.CurrentTechnique.Passes )
{
pass.Apply();
#pragma warning disable CS0618 // // FNA does not expose an alternative method.
Core.graphicsDevice.DrawIndexedPrimitives(
primitiveType: PrimitiveType.TriangleList,
baseVertex: vtxOffset,
minVertexIndex: 0,
numVertices: cmdList.VtxBuffer.Size,
startIndex: idxOffset,
primitiveCount: (int)drawCmd.ElemCount / 3
);
#pragma warning restore CS0618
}
idxOffset += (int)drawCmd.ElemCount;
}
vtxOffset += cmdList.VtxBuffer.Size;
}
}
#endregion Internals
}
}