Sphere vertex shader sample (#87)

* Added sample and inverted the order of drawing for Gizmos and UI

* Added files

* Removed unnecessary code in shader

* Fixed indentation in file and comments in spanish

TGC.MonoGame.Samples/Content/Content.mgcb

@@ -286,6 +286,12 @@
 /processorParam:DebugMode=Auto
 /build:Effects/SkyBox.fx
 
+#begin Effects/SphereVertexShader.fx
+/importer:EffectImporter
+/processor:EffectProcessor
+/processorParam:DebugMode=Auto
+/build:Effects/SphereVertexShader.fx
+
 #begin Effects/Terrain.fx
 /importer:EffectImporter
 /processor:EffectProcessor

TGC.MonoGame.Samples/Content/Effects/SphereVertexShader.fx

@@ -0,0 +1,65 @@
+#if OPENGL
+    #define SV_POSITION POSITION
+    #define VS_SHADERMODEL vs_3_0
+    #define PS_SHADERMODEL ps_3_0
+#else
+    #define VS_SHADERMODEL vs_4_0_level_9_1
+    #define PS_SHADERMODEL ps_4_0_level_9_1
+#endif
+
+// Custom Effects - https://docs.monogame.net/articles/content/custom_effects.html
+// High-level shader language (HLSL) - https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl
+// Programming guide for HLSL - https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-pguide
+// Reference for HLSL - https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-reference
+// HLSL Semantics - https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-semantics
+
+uniform float4x4 World;
+uniform float4x4 View;
+uniform float4x4 Projection;
+uniform float Time = 0;
+
+struct VertexShaderInput
+{
+    // Local Space Position
+    float4 Position : POSITION0;
+    float3 Normal : NORMAL0;
+};
+
+struct VertexShaderOutput
+{
+    // Projection Space Position
+    float4 Position : SV_POSITION;
+};
+
+VertexShaderOutput MainVS(in VertexShaderInput input)
+{
+    VertexShaderOutput output = (VertexShaderOutput)0;
+
+    input.Position.x += 0.05 * sin(input.Position.y * 10.0 + Time * 10.0);
+
+    // Local to World
+    float4 worldPosition = mul(input.Position, World);
+
+    // World to View
+    float4 viewPosition = mul(worldPosition, View);
+
+    // View to Projection 
+    output.Position = mul(viewPosition, Projection);
+
+    return output;
+}
+
+float4 MainPS(VertexShaderOutput input) : COLOR
+{
+    return float4(0.0, 0.0, 0.0, 1.0);
+}
+
+technique BaseTechnique
+{
+    pass P0
+    {
+        VertexShader = compile VS_SHADERMODEL MainVS();
+        PixelShader = compile PS_SHADERMODEL MainPS();
+    }
+};
+

TGC.MonoGame.Samples/Samples/Shaders/SphereVertexShader.cs

@@ -0,0 +1,82 @@
+using System;
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+using TGC.MonoGame.Samples.Cameras;
+using TGC.MonoGame.Samples.Geometries;
+using TGC.MonoGame.Samples.Viewer;
+
+namespace TGC.MonoGame.Samples.Samples.Shaders;
+
+/// <summary>
+///     Sphere Basic Shader:
+///     Units Involved:
+///     # Unit 8 - Video Adapters - Shaders.
+///     A basic vertex shader on a sphere.
+///     Author: Ronán Vinitzca
+/// </summary>
+public class SphereVertexShader : TGCSample
+{
+    private Camera _camera;
+
+    private Effect _effect;
+
+    private SpherePrimitive _sphere;
+
+    public SphereVertexShader(TGCViewer game) : base(game)
+    {
+        Category = TGCSampleCategory.Shaders;
+        Name = "SphereVertexShader";
+        Description = "Basic Sample for demonstrating Vertex Shaders.";
+    }
+
+    public override void Initialize()
+    {
+        _camera = new StaticCamera(GraphicsDevice.Viewport.AspectRatio,  Vector3.Forward * 4f, Vector3.Backward, Vector3.Up);
+        base.Initialize();
+    }
+
+    protected override void LoadContent()
+    {
+        _sphere = new SpherePrimitive(GraphicsDevice, 2f, 32);
+
+        // Load a shader using Content pipeline.
+        _effect = Game.Content.Load<Effect>(ContentFolderEffects + "SphereVertexShader");
+
+        base.LoadContent();
+    }
+
+    public override void Update(GameTime gameTime)
+    {
+        _camera.Update(gameTime);
+
+        Game.Gizmos.UpdateViewProjection(_camera.View, _camera.Projection);
+
+        base.Update(gameTime);
+    }
+
+    public override void Draw(GameTime gameTime)
+    {
+        Game.Background = Color.CornflowerBlue;
+
+        // Draw using wireframe and store old rasterizer state
+        var oldRasterizerState = GraphicsDevice.RasterizerState;
+        var rasterizerState = new RasterizerState();
+        rasterizerState.CullMode = CullMode.None;
+        rasterizerState.FillMode = FillMode.WireFrame;
+        GraphicsDevice.RasterizerState = rasterizerState;
+
+        var time = Convert.ToSingle(gameTime.TotalGameTime.TotalSeconds);
+
+        _effect.Parameters["Time"]?.SetValue(time);
+        _effect.Parameters["World"].SetValue(Matrix.Identity);
+        _effect.Parameters["View"].SetValue(_camera.View);
+        _effect.Parameters["Projection"].SetValue(_camera.Projection);
+
+        _sphere.Draw(_effect);
+
+        // Restore old rasterizer state
+        GraphicsDevice.RasterizerState = oldRasterizerState;
+
+        base.Draw(gameTime);
+    }
+}

TGC.MonoGame.Samples/Viewer/TGCViewer.cs

@@ -118,8 +118,8 @@ protected override void Draw(GameTime gameTime)
         {
             GraphicsDevice.Clear(Background);
             base.Draw(gameTime);
-            Model.DrawSampleExplorer(gameTime);
             Gizmos.Draw();
+            Model.DrawSampleExplorer(gameTime);
         }
 
         /// <summary>