- added the softpoly and Vulkan backend code fron GZDoom.

Not hooked up yet.

source/common/rendering/polyrenderer/drawers/screen_triangle.h

@@ -0,0 +1,129 @@
+/*
+**  Polygon Doom software renderer
+**  Copyright (c) 2016 Magnus Norddahl
+**
+**  This software is provided 'as-is', without any express or implied
+**  warranty.  In no event will the authors be held liable for any damages
+**  arising from the use of this software.
+**
+**  Permission is granted to anyone to use this software for any purpose,
+**  including commercial applications, and to alter it and redistribute it
+**  freely, subject to the following restrictions:
+**
+**  1. The origin of this software must not be misrepresented; you must not
+**     claim that you wrote the original software. If you use this software
+**     in a product, an acknowledgment in the product documentation would be
+**     appreciated but is not required.
+**  2. Altered source versions must be plainly marked as such, and must not be
+**     misrepresented as being the original software.
+**  3. This notice may not be removed or altered from any source distribution.
+**
+*/
+
+#pragma once
+
+#include <cstdint>
+#include <vector>
+#include <float.h>
+#include "renderstyle.h"
+//#include "rendering/swrenderer/drawers/r_draw.h"
+
+class FString;
+class PolyTriangleThreadData;
+
+struct ScreenTriVertex
+{
+	float x, y, z, w;
+	float u, v;
+	float worldX, worldY, worldZ;
+	float a, r, g, b;
+	float gradientdistZ;
+};
+
+struct ScreenTriangleStepVariables
+{
+	float W, U, V;
+	float WorldX, WorldY, WorldZ;
+	float A, R, G, B;
+	float GradientdistZ;
+};
+
+struct TriDrawTriangleArgs
+{
+	ScreenTriVertex *v1;
+	ScreenTriVertex *v2;
+	ScreenTriVertex *v3;
+	ScreenTriangleStepVariables gradientX;
+	ScreenTriangleStepVariables gradientY;
+
+	bool CalculateGradients()
+	{
+		float bottomX = (v2->x - v3->x) * (v1->y - v3->y) - (v1->x - v3->x) * (v2->y - v3->y);
+		float bottomY = (v1->x - v3->x) * (v2->y - v3->y) - (v2->x - v3->x) * (v1->y - v3->y);
+		if ((bottomX >= -FLT_EPSILON && bottomX <= FLT_EPSILON) || (bottomY >= -FLT_EPSILON && bottomY <= FLT_EPSILON))
+			return false;
+
+		gradientX.W = FindGradientX(bottomX, 1.0f, 1.0f, 1.0f);
+		gradientX.U = FindGradientX(bottomX, v1->u, v2->u, v3->u);
+		gradientX.V = FindGradientX(bottomX, v1->v, v2->v, v3->v);
+		gradientX.WorldX = FindGradientX(bottomX, v1->worldX, v2->worldX, v3->worldX);
+		gradientX.WorldY = FindGradientX(bottomX, v1->worldY, v2->worldY, v3->worldY);
+		gradientX.WorldZ = FindGradientX(bottomX, v1->worldZ, v2->worldZ, v3->worldZ);
+		gradientX.A = FindGradientX(bottomX, v1->a, v2->a, v3->a);
+		gradientX.R = FindGradientX(bottomX, v1->r, v2->r, v3->r);
+		gradientX.G = FindGradientX(bottomX, v1->g, v2->g, v3->g);
+		gradientX.B = FindGradientX(bottomX, v1->b, v2->b, v3->b);
+		gradientX.GradientdistZ = FindGradientX(bottomX, v1->gradientdistZ, v2->gradientdistZ, v3->gradientdistZ);
+
+		gradientY.W = FindGradientY(bottomY, 1.0f, 1.0f, 1.0f);
+		gradientY.U = FindGradientY(bottomY, v1->u, v2->u, v3->u);
+		gradientY.V = FindGradientY(bottomY, v1->v, v2->v, v3->v);
+		gradientY.WorldX = FindGradientY(bottomY, v1->worldX, v2->worldX, v3->worldX);
+		gradientY.WorldY = FindGradientY(bottomY, v1->worldY, v2->worldY, v3->worldY);
+		gradientY.WorldZ = FindGradientY(bottomY, v1->worldZ, v2->worldZ, v3->worldZ);
+		gradientY.A = FindGradientY(bottomY, v1->a, v2->a, v3->a);
+		gradientY.R = FindGradientY(bottomY, v1->r, v2->r, v3->r);
+		gradientY.G = FindGradientY(bottomY, v1->g, v2->g, v3->g);
+		gradientY.B = FindGradientY(bottomY, v1->b, v2->b, v3->b);
+		gradientY.GradientdistZ = FindGradientY(bottomY, v1->gradientdistZ, v2->gradientdistZ, v3->gradientdistZ);
+
+		return true;
+	}
+
+private:
+	float FindGradientX(float bottomX, float c0, float c1, float c2)
+	{
+		c0 *= v1->w;
+		c1 *= v2->w;
+		c2 *= v3->w;
+		return ((c1 - c2) * (v1->y - v3->y) - (c0 - c2) * (v2->y - v3->y)) / bottomX;
+	}
+
+	float FindGradientY(float bottomY, float c0, float c1, float c2)
+	{
+		c0 *= v1->w;
+		c1 *= v2->w;
+		c2 *= v3->w;
+		return ((c1 - c2) * (v1->x - v3->x) - (c0 - c2) * (v2->x - v3->x)) / bottomY;
+	}
+};
+
+class ScreenTriangle
+{
+public:
+	static void Draw(const TriDrawTriangleArgs* args, PolyTriangleThreadData* thread);
+
+private:
+	static void(*TestSpanOpts[])(int y, int x0, int x1, const TriDrawTriangleArgs* args, PolyTriangleThreadData* thread);
+};
+
+enum SWTestSpan
+{
+	SWTRI_DepthTest = 1,
+	SWTRI_StencilTest = 2
+};
+
+struct TestSpanOpt0 { static const int Flags = 0; };
+struct TestSpanOpt1 { static const int Flags = 1; };
+struct TestSpanOpt2 { static const int Flags = 2; };
+struct TestSpanOpt3 { static const int Flags = 3; };