gzdoom-gles/src/swrenderer/viewport/r_viewport.h

#pragma once

#include <stddef.h>
#include <memory>
#include "v_video.h"
#include "r_defs.h"
#include "polyrenderer/math/gpu_types.h"

#define MINZ double((2048*4) / double(1 << 20))

namespace swrenderer
{
	class RenderThread;

	class RenderViewport
	{
	public:
		RenderViewport();
		~RenderViewport();
		
		void SetViewport(RenderThread *thread, int width, int height, float trueratio);
		void SetupFreelook();
		
		void SetupPolyViewport(RenderThread *thread);

		Mat4f WorldToView;
		Mat4f ViewToClip;
		Mat4f WorldToClip;

		DCanvas *RenderTarget = nullptr;
		bool RenderingToCanvas = false;

		FViewWindow viewwindow;
		FRenderViewpoint viewpoint;

		double FocalLengthX = 0.0;
		double FocalLengthY = 0.0;
		double InvZtoScale = 0.0;
		double WallTMapScale2 = 0.0;
		double CenterX = 0.0;
		double CenterY = 0.0;
		double YaspectMul = 0.0;
		double IYaspectMul = 0.0;
		double globaluclip = 0.0;
		double globaldclip = 0.0;

		fixed_t viewingrangerecip = 0;
		double BaseYaspectMul = 0.0; // yaspectmul without a forced aspect ratio

		// The xtoviewangleangle[] table maps a screen pixel
		// to the lowest viewangle that maps back to x ranges
		// from clipangle to -clipangle.
		angle_t xtoviewangle[MAXWIDTH + 1];

		uint8_t *GetDest(int x, int y);

		DVector3 PointWorldToView(const DVector3 &worldPos) const;
		DVector3 PointWorldToScreen(const DVector3 &worldPos) const;
		DVector3 PointViewToScreen(const DVector3 &viewPos) const;

		DVector2 PointWorldToView(const DVector2 &worldPos) const;
		DVector2 ScaleViewToScreen(const DVector2 &scale, double viewZ, bool pixelstretch = true) const;

		double PlaneDepth(int screenY, double planeHeight) const
		{
			if (screenY + 0.5 < CenterY)
				return FocalLengthY / (CenterY - screenY - 0.5) * planeHeight;
			else
				return FocalLengthY / (screenY + 0.5 - CenterY) * planeHeight;
		}

		double ScreenToViewX(int screenX, double viewZ) const
		{
			return (screenX + 0.5 - CenterX) / FocalLengthX * viewZ;
		}

		double ScreenToViewY(int screenY, double viewZ) const
		{
			return (CenterY - screenY - 0.5) / FocalLengthY * viewZ;
		}

	private:
		void InitTextureMapping();
		void SetupBuffer();

		static Mat4f SoftwareWorldToView(const FRenderViewpoint &viewpoint);

		Mat4f SoftwareViewToClip();
	};
}