From b1f867f1072d68978e0de3a006987084cf7822c0 Mon Sep 17 00:00:00 2001
From: Jean-Baptiste Perrier <jeanbapt.perrier@gmail.com>
Date: Mon, 15 Feb 2021 19:33:25 +0100
Subject: [PATCH] Add DrawVertices & FillTriangle funcs.

---
 Source/Engine/Render2D/Render2D.cpp | 38 +++++++++++++++++++++++++++++
 Source/Engine/Render2D/Render2D.h   | 26 ++++++++++++++++++++
 2 files changed, 64 insertions(+)

diff --git a/Source/Engine/Render2D/Render2D.cpp b/Source/Engine/Render2D/Render2D.cpp
index e834c5939..818265551 100644
--- a/Source/Engine/Render2D/Render2D.cpp
+++ b/Source/Engine/Render2D/Render2D.cpp
@@ -1744,3 +1744,41 @@ void Render2D::DrawBlur(const Rectangle& rect, float blurStrength)
     drawCall.AsBlur.BottomRightY = p.Y;
     WriteRect(rect, Color::White);
 }
+
+void Render2D::DrawVertices(GPUTexture* t, const Array<Vector2> vertices, const Array<Vector2> uvs)
+{
+    RENDER2D_CHECK_RENDERING_STATE;
+    
+    Render2DDrawCall& drawCall = DrawCalls.AddOne();
+    drawCall.Type = DrawCallType::FillTexture;
+    drawCall.StartIB = IBIndex;
+    drawCall.CountIB = vertices.Count();
+    drawCall.AsTexture.Ptr = t;
+
+    for (int32 i = 0; i < vertices.Count(); i += 3)
+        WriteTri(vertices[i], vertices[i + 1], vertices[i + 2], uvs[i], uvs[i + 1], uvs[i + 2]);
+}
+
+void Render2D::DrawVertices(const Array<Vector2> vertices, const Array<Color> colors, bool useAlpha)
+{
+    RENDER2D_CHECK_RENDERING_STATE;
+    
+    Render2DDrawCall& drawCall = DrawCalls.AddOne();
+    drawCall.Type = useAlpha ? DrawCallType::FillRect : DrawCallType::FillRectNoAlpha;
+    drawCall.StartIB = IBIndex;
+    drawCall.CountIB = vertices.Count();
+
+    for (int32 i = 0; i < vertices.Count(); i += 3)
+        WriteTri(vertices[i], vertices[i + 1], vertices[i + 2], colors[i], colors[i + 1], colors[i + 2]);
+}
+
+void Render2D::FillTriangle(const Vector2& p0, const Vector2& p1, const Vector2& p2, const Color& color)
+{
+    RENDER2D_CHECK_RENDERING_STATE;
+    
+    Render2DDrawCall& drawCall = DrawCalls.AddOne();
+    drawCall.Type = color.A < 1.0f ? DrawCallType::FillRect : DrawCallType::FillRectNoAlpha;
+    drawCall.StartIB = IBIndex;
+    drawCall.CountIB = 3;
+    WriteTri(p0, p1, p2, color, color, color);
+}
diff --git a/Source/Engine/Render2D/Render2D.h b/Source/Engine/Render2D/Render2D.h
index a421c56a6..1cf32a886 100644
--- a/Source/Engine/Render2D/Render2D.h
+++ b/Source/Engine/Render2D/Render2D.h
@@ -4,6 +4,7 @@
 
 #include "Engine/Core/Math/Color.h"
 #include "Engine/Scripting/ScriptingType.h"
+#include "Engine/Core/Collections/Array.h"
 
 struct SpriteHandle;
 struct TextLayoutOptions;
@@ -339,4 +340,29 @@ public:
     /// <param name="rect">The target rectangle to draw (blurs its background).</param>
     /// <param name="blurStrength">The blur strength defines how blurry the background is. Larger numbers increase blur, resulting in a larger runtime cost on the GPU.</param>
     API_FUNCTION() static void DrawBlur(const Rectangle& rect, float blurStrength);
+
+    /// <summary>
+    /// Draws vertices array.
+    /// </summary>
+    /// <param name="t">The texture.</param>
+    /// <param name="vertices">The vertices array.</param>
+    /// <param name="uvs">The uvs array.</param>
+    API_FUNCTION() static void DrawVertices(GPUTexture* t, Array<Vector2> vertices, Array<Vector2> uvs);
+    
+    /// <summary>
+    /// Draws vertices array.
+    /// </summary>
+    /// <param name="vertices">The vertices array.</param>
+    /// <param name="colors">The colors array.</param>
+    /// <param name="useAlpha">If true alpha blending will be enabled.</param>
+    API_FUNCTION() static void DrawVertices(Array<Vector2> vertices, Array<Color> colors, bool useAlpha);
+
+    /// <summary>
+    /// Fills a triangular area.
+    /// </summary>
+    /// <param name="p0">The first point.</param>
+    /// <param name="p1">The second point.</param>
+    /// <param name="p2">The third point.</param>
+    /// <param name="color">The color.</param>
+    API_FUNCTION() static void FillTriangle(const Vector2& p0, const Vector2& p1, const Vector2& p2, const Color& color);
 };