V2.05 - More Decal Routines

Added DrawPartialWarpedDecal()
Added DrawPartialRotatedDecal()

olcPixelGameEngine.h

@@ -2,7 +2,7 @@
 	olcPixelGameEngine.h
 
 	+-------------------------------------------------------------+
-	|           OneLoneCoder Pixel Game Engine v2.04              |
+	|           OneLoneCoder Pixel Game Engine v2.05              |
 	|  "What do you need? Pixels... Lots of Pixels..." - javidx9  |
 	+-------------------------------------------------------------+
 
@@ -111,7 +111,7 @@
 	JackOJC, KrossX, Huhlig, Dragoneye, Appa, JustinRichardsMusic, SliceNDice
 	Ralakus, Gorbit99, raoul, joshinils, benedani, Moros1138, SaladinAkara & MagetzUb 
 	for advice, ideas and testing, and I'd like to extend my appreciation to the 
-	135K YouTube followers,	60+ Patreons and 6K Discord server members who give me 
+	144K YouTube followers,	70+ Patreons and 6K Discord server members who give me 
 	the motivation to keep going with all this :D
 
 	Significant Contributors: @MaGetzUb, @slavka, @Dragoneye & @Gorbit99
@@ -134,6 +134,7 @@
 	2.02: Added Decal destructor, optimised Pixel constructor
 	2.03: Added FreeBSD flags, Added DrawStringDecal()
 	2.04: Windows Full-Screen bug fixed
+	2.05: Added DrawPartialWarpedDecal(), Added DrawPartialRotatedDecal()
 */
 
 //////////////////////////////////////////////////////////////////////////////////////////
@@ -201,7 +202,6 @@ int main()
 #include <list>
 #include <thread>
 #include <atomic>
-#include <condition_variable>
 #include <fstream>
 #include <map>
 #include <functional>
@@ -656,6 +656,12 @@ namespace olc
 		void DrawRotatedDecal(const olc::vf2d& pos, olc::Decal* decal, const float fAngle, const olc::vf2d& center = { 0.0f, 0.0f }, const olc::vf2d& scale = { 1.0f,1.0f }, const olc::Pixel& tint = olc::WHITE);
 
 		void DrawStringDecal(const olc::vf2d& pos, const std::string& sText, const Pixel col = olc::WHITE, const olc::vf2d& scale = { 1.0f, 1.0f });
+		void DrawPartialRotatedDecal(const olc::vf2d& pos, olc::Decal* decal, const float fAngle, const olc::vf2d& center, const olc::vf2d& source_pos, const olc::vf2d& source_size, const olc::vf2d& scale = { 1.0f, 1.0f }, const olc::Pixel& tint = olc::WHITE);
+
+		void DrawPartialWarpedDecal(olc::Decal* decal, const olc::vf2d(&pos)[4], const olc::vf2d& source_pos, const olc::vf2d& source_size, const olc::Pixel& tint = olc::WHITE);
+		void DrawPartialWarpedDecal(olc::Decal* decal, const olc::vf2d* pos, const olc::vf2d& source_pos, const olc::vf2d& source_size, const olc::Pixel& tint = olc::WHITE);
+		void DrawPartialWarpedDecal(olc::Decal* decal, const std::array<olc::vf2d, 4>& pos, const olc::vf2d& source_pos, const olc::vf2d& source_size, const olc::Pixel& tint = olc::WHITE);
+
 
 		// Draws a single line of text
 		void DrawString(int32_t x, int32_t y, const std::string& sText, Pixel col = olc::WHITE, uint32_t scale = 1);
@@ -1857,6 +1863,60 @@ namespace olc
 		vLayers[nTargetLayer].vecDecalInstance.push_back(di);
 	}
 
+	void PixelGameEngine::DrawPartialRotatedDecal(const olc::vf2d& pos, olc::Decal* decal, const float fAngle, const olc::vf2d& center, const olc::vf2d& source_pos, const olc::vf2d& source_size, const olc::vf2d& scale, const olc::Pixel& tint)
+	{
+		DecalInstance di;
+		di.decal = decal;
+		di.tint = tint;
+		di.pos[0] = (olc::vf2d(0.0f, 0.0f) - center) * scale;
+		di.pos[1] = (olc::vf2d(0.0f, source_size.y) - center) * scale;
+		di.pos[2] = (olc::vf2d(source_size.x, source_size.y) - center) * scale;
+		di.pos[3] = (olc::vf2d(source_size.x, 0.0f) - center) * scale;
+		float c = cos(fAngle), s = sin(fAngle);
+		for (int i = 0; i < 4; i++)
+		{
+			di.pos[i] = pos + olc::vf2d(di.pos[i].x * c - di.pos[i].y * s, di.pos[i].x * s + di.pos[i].y * c);
+			di.pos[i] = di.pos[i] * vInvScreenSize * 2.0f - olc::vf2d(1.0f, 1.0f);
+			di.pos[i].y *= -1.0f;
+		}
+
+		olc::vf2d uvtl = source_pos * decal->vUVScale;
+		olc::vf2d uvbr = uvtl + (source_size * decal->vUVScale);
+		di.uv[0] = { uvtl.x, uvtl.y }; di.uv[1] = { uvtl.x, uvbr.y };
+		di.uv[2] = { uvbr.x, uvbr.y }; di.uv[3] = { uvbr.x, uvtl.y };
+
+		vLayers[nTargetLayer].vecDecalInstance.push_back(di);
+	}
+
+	void PixelGameEngine::DrawPartialWarpedDecal(olc::Decal* decal, const olc::vf2d* pos, const olc::vf2d& source_pos, const olc::vf2d& source_size, const olc::Pixel& tint)
+	{
+		DecalInstance di;
+		di.decal = decal;
+		di.tint = tint;
+		olc::vf2d center;
+		float rd = ((pos[2].x - pos[0].x) * (pos[3].y - pos[1].y) - (pos[3].x - pos[1].x) * (pos[2].y - pos[0].y));
+		if (rd != 0)
+		{
+			olc::vf2d uvtl = source_pos * decal->vUVScale; 
+			olc::vf2d uvbr = uvtl + (source_size * decal->vUVScale);
+			di.uv[0] = { uvtl.x, uvtl.y }; di.uv[1] = { uvtl.x, uvbr.y };
+			di.uv[2] = { uvbr.x, uvbr.y }; di.uv[3] = { uvbr.x, uvtl.y };
+
+			rd = 1.0f / rd;
+			float rn = ((pos[3].x - pos[1].x) * (pos[0].y - pos[1].y) - (pos[3].y - pos[1].y) * (pos[0].x - pos[1].x)) * rd;
+			float sn = ((pos[2].x - pos[0].x) * (pos[0].y - pos[1].y) - (pos[2].y - pos[0].y) * (pos[0].x - pos[1].x)) * rd;
+			if (!(rn < 0.f || rn > 1.f || sn < 0.f || sn > 1.f)) center = pos[0] + rn * (pos[2] - pos[0]);
+			float d[4];	for (int i = 0; i < 4; i++)	d[i] = (pos[i] - center).mag();
+			for (int i = 0; i < 4; i++)
+			{
+				float q = d[i] == 0.0f ? 1.0f : (d[i] + d[(i + 2) & 3]) / d[(i + 2) & 3];
+				di.uv[i] *= q; di.w[i] *= q;
+				di.pos[i] = { (pos[i].x * vInvScreenSize.x) * 2.0f - 1.0f, ((pos[i].y * vInvScreenSize.y) * 2.0f - 1.0f) * -1.0f };
+			}			
+			vLayers[nTargetLayer].vecDecalInstance.push_back(di);
+		}
+	}
+
 	void PixelGameEngine::DrawWarpedDecal(olc::Decal* decal, const olc::vf2d* pos, const olc::Pixel& tint)
 	{
 		// Thanks Nathan Reed, a brilliant article explaining whats going on here
@@ -1884,15 +1944,17 @@ namespace olc
 	}
 
 	void PixelGameEngine::DrawWarpedDecal(olc::Decal* decal, const std::array<olc::vf2d, 4>& pos, const olc::Pixel& tint)
-	{
+	{ DrawWarpedDecal(decal, pos.data(), tint);	}
-		DrawWarpedDecal(decal, pos.data(), tint);
-	}
 
 	void PixelGameEngine::DrawWarpedDecal(olc::Decal* decal, const olc::vf2d(&pos)[4], const olc::Pixel& tint)
-	{
+	{ DrawWarpedDecal(decal, &pos[0], tint); }
-		DrawWarpedDecal(decal, &pos[0], tint);		
+
-	}
+	void PixelGameEngine::DrawPartialWarpedDecal(olc::Decal* decal, const std::array<olc::vf2d, 4>& pos, const olc::vf2d& source_pos, const olc::vf2d& source_size, const olc::Pixel& tint)
+	{ DrawPartialWarpedDecal(decal, pos.data(), source_pos, source_size, tint); }
 
+	void PixelGameEngine::DrawPartialWarpedDecal(olc::Decal* decal, const olc::vf2d(&pos)[4], const olc::vf2d& source_pos, const olc::vf2d& source_size, const olc::Pixel& tint)
+	{ DrawPartialWarpedDecal(decal, &pos[0], source_pos, source_size, tint); }
+	   
 	void PixelGameEngine::DrawStringDecal(const olc::vf2d& pos, const std::string& sText, const Pixel col, const olc::vf2d& scale)
 	{
 		olc::vf2d spos = { 0.0f, 0.0f };