Add support for capping sky with a solid color

src/r_draw.cpp

@@ -110,6 +110,8 @@ DWORD			vplce[4];
 DWORD			vince[4];
 BYTE*			palookupoffse[4];
 const BYTE*		bufplce[4];
+const BYTE*		bufplce2[4];
+uint32_t		bufheight[4];
 
 // just for profiling 
 int 			dccount;
@@ -2142,6 +2144,245 @@ void tmvline4_revsubclamp ()
 	} while (--count);
 }
 
+void R_DrawSingleSkyCol1(uint32_t solid_top, uint32_t solid_bottom)
+{
+	uint8_t *dest = dc_dest;
+	int count = dc_count;
+	int pitch = dc_pitch;
+	const uint8_t *source0 = bufplce[0];
+	int textureheight0 = bufheight[0];
+
+	int32_t frac = vplce[0];
+	int32_t fracstep = vince[0];
+
+	int start_fade = 2; // How fast it should fade out
+
+	int solid_top_r = RPART(solid_top);
+	int solid_top_g = GPART(solid_top);
+	int solid_top_b = BPART(solid_top);
+	int solid_bottom_r = RPART(solid_bottom);
+	int solid_bottom_g = GPART(solid_bottom);
+	int solid_bottom_b = BPART(solid_bottom);
+
+	for (int index = 0; index < count; index++)
+	{
+		uint32_t sample_index = (((((uint32_t)frac) << 8) >> FRACBITS) * textureheight0) >> FRACBITS;
+		uint8_t fg = source0[sample_index];
+
+		int alpha_top = MAX(MIN(frac >> (16 - start_fade), 256), 0);
+		int alpha_bottom = MAX(MIN(((2 << 24) - frac) >> (16 - start_fade), 256), 0);
+
+		if (alpha_top == 256 && alpha_bottom == 256)
+		{
+			*dest = fg;
+		}
+		else
+		{
+			int inv_alpha_top = 256 - alpha_top;
+			int inv_alpha_bottom = 256 - alpha_bottom;
+
+			const auto &c = GPalette.BaseColors[fg];
+			int c_red = c.r;
+			int c_green = c.g;
+			int c_blue = c.b;
+			c_red = (c_red * alpha_top + solid_top_r * inv_alpha_top) >> 8;
+			c_green = (c_green * alpha_top + solid_top_g * inv_alpha_top) >> 8;
+			c_blue = (c_blue * alpha_top + solid_top_b * inv_alpha_top) >> 8;
+			c_red = (c_red * alpha_bottom + solid_bottom_r * inv_alpha_bottom) >> 8;
+			c_green = (c_green * alpha_bottom + solid_bottom_g * inv_alpha_bottom) >> 8;
+			c_blue = (c_blue * alpha_bottom + solid_bottom_b * inv_alpha_bottom) >> 8;
+			*dest = RGB32k.RGB[(c_red >> 3)][(c_green >> 3)][(c_blue >> 3)];
+		}
+
+		frac += fracstep;
+		dest += pitch;
+	}
+}
+
+void R_DrawSingleSkyCol4(uint32_t solid_top, uint32_t solid_bottom)
+{
+	for (int col = 0; col < 4; col++)
+	{
+		uint8_t *dest = dc_dest + col;
+		int count = dc_count;
+		int pitch = dc_pitch;
+		const uint8_t *source0 = bufplce[col];
+		int textureheight0 = bufheight[0];
+
+		int32_t frac = vplce[col];
+		int32_t fracstep = vince[col];
+
+		int start_fade = 2; // How fast it should fade out
+
+		int solid_top_r = RPART(solid_top);
+		int solid_top_g = GPART(solid_top);
+		int solid_top_b = BPART(solid_top);
+		int solid_bottom_r = RPART(solid_bottom);
+		int solid_bottom_g = GPART(solid_bottom);
+		int solid_bottom_b = BPART(solid_bottom);
+
+		for (int index = 0; index < count; index++)
+		{
+			uint32_t sample_index = (((((uint32_t)frac) << 8) >> FRACBITS) * textureheight0) >> FRACBITS;
+			uint8_t fg = source0[sample_index];
+
+			int alpha_top = MAX(MIN(frac >> (16 - start_fade), 256), 0);
+			int alpha_bottom = MAX(MIN(((2 << 24) - frac) >> (16 - start_fade), 256), 0);
+
+			if (alpha_top == 256 && alpha_bottom == 256)
+			{
+				*dest = fg;
+			}
+			else
+			{
+				int inv_alpha_top = 256 - alpha_top;
+				int inv_alpha_bottom = 256 - alpha_bottom;
+
+				const auto &c = GPalette.BaseColors[fg];
+				int c_red = c.r;
+				int c_green = c.g;
+				int c_blue = c.b;
+				c_red = (c_red * alpha_top + solid_top_r * inv_alpha_top) >> 8;
+				c_green = (c_green * alpha_top + solid_top_g * inv_alpha_top) >> 8;
+				c_blue = (c_blue * alpha_top + solid_top_b * inv_alpha_top) >> 8;
+				c_red = (c_red * alpha_bottom + solid_bottom_r * inv_alpha_bottom) >> 8;
+				c_green = (c_green * alpha_bottom + solid_bottom_g * inv_alpha_bottom) >> 8;
+				c_blue = (c_blue * alpha_bottom + solid_bottom_b * inv_alpha_bottom) >> 8;
+				*dest = RGB32k.RGB[(c_red >> 3)][(c_green >> 3)][(c_blue >> 3)];
+			}
+
+			frac += fracstep;
+			dest += pitch;
+		}
+	}
+}
+
+void R_DrawDoubleSkyCol1(uint32_t solid_top, uint32_t solid_bottom)
+{
+	uint8_t *dest = dc_dest;
+	int count = dc_count;
+	int pitch = dc_pitch;
+	const uint8_t *source0 = bufplce[0];
+	const uint8_t *source1 = bufplce2[0];
+	int textureheight0 = bufheight[0];
+	uint32_t maxtextureheight1 = bufheight[1] - 1;
+
+	int32_t frac = vplce[0];
+	int32_t fracstep = vince[0];
+
+	int start_fade = 2; // How fast it should fade out
+
+	int solid_top_r = RPART(solid_top);
+	int solid_top_g = GPART(solid_top);
+	int solid_top_b = BPART(solid_top);
+	int solid_bottom_r = RPART(solid_bottom);
+	int solid_bottom_g = GPART(solid_bottom);
+	int solid_bottom_b = BPART(solid_bottom);
+
+	for (int index = 0; index < count; index++)
+	{
+		uint32_t sample_index = (((((uint32_t)frac) << 8) >> FRACBITS) * textureheight0) >> FRACBITS;
+		uint8_t fg = source0[sample_index];
+		if (fg == 0)
+		{
+			uint32_t sample_index2 = MIN(sample_index, maxtextureheight1);
+			fg = source1[sample_index2];
+		}
+
+		int alpha_top = MAX(MIN(frac >> (16 - start_fade), 256), 0);
+		int alpha_bottom = MAX(MIN(((2 << 24) - frac) >> (16 - start_fade), 256), 0);
+
+		if (alpha_top == 256 && alpha_bottom == 256)
+		{
+			*dest = fg;
+		}
+		else
+		{
+			int inv_alpha_top = 256 - alpha_top;
+			int inv_alpha_bottom = 256 - alpha_bottom;
+
+			const auto &c = GPalette.BaseColors[fg];
+			int c_red = c.r;
+			int c_green = c.g;
+			int c_blue = c.b;
+			c_red = (c_red * alpha_top + solid_top_r * inv_alpha_top) >> 8;
+			c_green = (c_green * alpha_top + solid_top_g * inv_alpha_top) >> 8;
+			c_blue = (c_blue * alpha_top + solid_top_b * inv_alpha_top) >> 8;
+			c_red = (c_red * alpha_bottom + solid_bottom_r * inv_alpha_bottom) >> 8;
+			c_green = (c_green * alpha_bottom + solid_bottom_g * inv_alpha_bottom) >> 8;
+			c_blue = (c_blue * alpha_bottom + solid_bottom_b * inv_alpha_bottom) >> 8;
+			*dest = RGB32k.RGB[(c_red >> 3)][(c_green >> 3)][(c_blue >> 3)];
+		}
+
+		frac += fracstep;
+		dest += pitch;
+	}
+}
+
+void R_DrawDoubleSkyCol4(uint32_t solid_top, uint32_t solid_bottom)
+{
+	for (int col = 0; col < 4; col++)
+	{
+		uint8_t *dest = dc_dest + col;
+		int count = dc_count;
+		int pitch = dc_pitch;
+		const uint8_t *source0 = bufplce[col];
+		const uint8_t *source1 = bufplce2[col];
+		int textureheight0 = bufheight[0];
+		uint32_t maxtextureheight1 = bufheight[1] - 1;
+
+		int32_t frac = vplce[col];
+		int32_t fracstep = vince[col];
+
+		int start_fade = 2; // How fast it should fade out
+
+		int solid_top_r = RPART(solid_top);
+		int solid_top_g = GPART(solid_top);
+		int solid_top_b = BPART(solid_top);
+		int solid_bottom_r = RPART(solid_bottom);
+		int solid_bottom_g = GPART(solid_bottom);
+		int solid_bottom_b = BPART(solid_bottom);
+
+		for (int index = 0; index < count; index++)
+		{
+			uint32_t sample_index = (((((uint32_t)frac) << 8) >> FRACBITS) * textureheight0) >> FRACBITS;
+			uint8_t fg = source0[sample_index];
+			if (fg == 0)
+			{
+				uint32_t sample_index2 = MIN(sample_index, maxtextureheight1);
+				fg = source1[sample_index2];
+			}
+
+			int alpha_top = MAX(MIN(frac >> (16 - start_fade), 256), 0);
+			int alpha_bottom = MAX(MIN(((2 << 24) - frac) >> (16 - start_fade), 256), 0);
+
+			if (alpha_top == 256 && alpha_bottom == 256)
+			{
+				*dest = fg;
+			}
+			else
+			{
+				int inv_alpha_top = 256 - alpha_top;
+				int inv_alpha_bottom = 256 - alpha_bottom;
+
+				const auto &c = GPalette.BaseColors[fg];
+				int c_red = c.r;
+				int c_green = c.g;
+				int c_blue = c.b;
+				c_red = (c_red * alpha_top + solid_top_r * inv_alpha_top) >> 8;
+				c_green = (c_green * alpha_top + solid_top_g * inv_alpha_top) >> 8;
+				c_blue = (c_blue * alpha_top + solid_top_b * inv_alpha_top) >> 8;
+				c_red = (c_red * alpha_bottom + solid_bottom_r * inv_alpha_bottom) >> 8;
+				c_green = (c_green * alpha_bottom + solid_bottom_g * inv_alpha_bottom) >> 8;
+				c_blue = (c_blue * alpha_bottom + solid_bottom_b * inv_alpha_bottom) >> 8;
+				*dest = RGB32k.RGB[(c_red >> 3)][(c_green >> 3)][(c_blue >> 3)];
+			}
+
+			frac += fracstep;
+			dest += pitch;
+		}
+	}
+}
 
 //==========================================================================
 //

src/r_draw.h

@@ -51,6 +51,8 @@ extern "C" DWORD		vplce[4];
 extern "C" DWORD		vince[4];
 extern "C" BYTE*		palookupoffse[4];
 extern "C" const BYTE*	bufplce[4];
+extern "C" const BYTE*	bufplce2[4];
+extern "C" uint32_t		bufheight[4];
 
 // [RH] Temporary buffer for column drawing
 extern "C" BYTE			*dc_temp;
@@ -293,4 +295,9 @@ void maskwallscan (int x1, int x2, short *uwal, short *dwal, float *swal, fixed_
 // transmaskwallscan is like maskwallscan, but it can also blend to the background
 void transmaskwallscan (int x1, int x2, short *uwal, short *dwal, float *swal, fixed_t *lwal, double yrepeat, const BYTE *(*getcol)(FTexture *tex, int col)=R_GetColumn);
 
+void R_DrawSingleSkyCol1(uint32_t solid_top, uint32_t solid_bottom);
+void R_DrawSingleSkyCol4(uint32_t solid_top, uint32_t solid_bottom);
+void R_DrawDoubleSkyCol1(uint32_t solid_top, uint32_t solid_bottom);
+void R_DrawDoubleSkyCol4(uint32_t solid_top, uint32_t solid_bottom);
+
 #endif

src/r_plane.cpp

@@ -63,6 +63,8 @@
 #pragma warning(disable:4244)
 #endif
 
+CVAR(Bool, r_capsky, true, CVAR_ARCHIVE | CVAR_GLOBALCONFIG);
+
 //EXTERN_CVAR (Int, tx)
 //EXTERN_CVAR (Int, ty)
 
@@ -898,8 +900,171 @@ static const BYTE *R_GetTwoSkyColumns (FTexture *fronttex, int x)
 	return composite;
 }
 
+static void R_DrawSkyColumnStripe(int start_x, int y1, int y2, int columns, double scale, double texturemid, double yrepeat)
+{
+	uint32_t height = frontskytex->GetHeight();
+
+	for (int i = 0; i < columns; i++)
+	{
+		double uv_stepd = skyiscale * yrepeat;
+		double v = (texturemid + uv_stepd * (y1 - CenterY + 0.5)) / height;
+		double v_step = uv_stepd / height;
+
+		uint32_t uv_pos = (uint32_t)(v * 0x01000000);
+		uint32_t uv_step = (uint32_t)(v_step * 0x01000000);
+
+		int x = start_x + i;
+		if (MirrorFlags & RF_XFLIP)
+			x = (viewwidth - x);
+
+		DWORD ang, angle1, angle2;
+
+		ang = (skyangle + xtoviewangle[x]) ^ skyflip;
+		angle1 = (DWORD)((UMulScale16(ang, frontcyl) + frontpos) >> FRACBITS);
+		angle2 = (DWORD)((UMulScale16(ang, backcyl) + backpos) >> FRACBITS);
+
+		bufplce[i] = (const BYTE *)frontskytex->GetColumn(angle1, nullptr);
+		bufplce2[i] = backskytex ? (const BYTE *)backskytex->GetColumn(angle2, nullptr) : nullptr;
+
+		vince[i] = uv_step;
+		vplce[i] = uv_pos;
+	}
+
+	bufheight[0] = height;
+	bufheight[1] = backskytex ? backskytex->GetHeight() : height;
+	dc_dest = (ylookup[y1] + start_x) + dc_destorg;
+	dc_count = y2 - y1;
+
+	uint32_t solid_top = frontskytex->GetSWSkyCapColor(false);
+	uint32_t solid_bottom = frontskytex->GetSWSkyCapColor(true);
+
+	if (columns == 4)
+		if (!backskytex)
+			R_DrawSingleSkyCol4(solid_top, solid_bottom);
+		else
+			R_DrawDoubleSkyCol4(solid_top, solid_bottom);
+	else
+		if (!backskytex)
+			R_DrawSingleSkyCol1(solid_top, solid_bottom);
+		else
+			R_DrawDoubleSkyCol1(solid_top, solid_bottom);
+}
+
+static void R_DrawSkyColumn(int start_x, int y1, int y2, int columns)
+{
+	if (1 << frontskytex->HeightBits == frontskytex->GetHeight())
+	{
+		double texturemid = skymid * frontskytex->Scale.Y + frontskytex->GetHeight();
+		R_DrawSkyColumnStripe(start_x, y1, y2, columns, frontskytex->Scale.Y, texturemid, frontskytex->Scale.Y);
+	}
+	else
+	{
+		double yrepeat = frontskytex->Scale.Y;
+		double scale = frontskytex->Scale.Y * skyscale;
+		double iscale = 1 / scale;
+		short drawheight = short(frontskytex->GetHeight() * scale);
+		double topfrac = fmod(skymid + iscale * (1 - CenterY), frontskytex->GetHeight());
+		if (topfrac < 0) topfrac += frontskytex->GetHeight();
+		double texturemid = topfrac - iscale * (1 - CenterY);
+		R_DrawSkyColumnStripe(start_x, y1, y2, columns, scale, texturemid, yrepeat);
+	}
+}
+
+static void R_DrawCapSky(visplane_t *pl)
+{
+	int x1 = pl->left;
+	int x2 = pl->right;
+	short *uwal = (short *)pl->top;
+	short *dwal = (short *)pl->bottom;
+
+	// Calculate where 4 column alignment begins and ends:
+	int aligned_x1 = clamp((x1 + 3) / 4 * 4, x1, x2);
+	int aligned_x2 = clamp(x2 / 4 * 4, x1, x2);
+
+	// First unaligned columns:
+	for (int x = x1; x < aligned_x1; x++)
+	{
+		int y1 = uwal[x];
+		int y2 = dwal[x];
+		if (y2 <= y1)
+			continue;
+
+		R_DrawSkyColumn(x, y1, y2, 1);
+	}
+
+	// The aligned columns
+	for (int x = aligned_x1; x < aligned_x2; x += 4)
+	{
+		// Find y1, y2, light and uv values for four columns:
+		int y1[4] = { uwal[x], uwal[x + 1], uwal[x + 2], uwal[x + 3] };
+		int y2[4] = { dwal[x], dwal[x + 1], dwal[x + 2], dwal[x + 3] };
+
+		// Figure out where we vertically can start and stop drawing 4 columns in one go
+		int middle_y1 = y1[0];
+		int middle_y2 = y2[0];
+		for (int i = 1; i < 4; i++)
+		{
+			middle_y1 = MAX(y1[i], middle_y1);
+			middle_y2 = MIN(y2[i], middle_y2);
+		}
+
+		// If we got an empty column in our set we cannot draw 4 columns in one go:
+		bool empty_column_in_set = false;
+		for (int i = 0; i < 4; i++)
+		{
+			if (y2[i] <= y1[i])
+				empty_column_in_set = true;
+		}
+		if (empty_column_in_set || middle_y2 <= middle_y1)
+		{
+			for (int i = 0; i < 4; i++)
+			{
+				if (y2[i] <= y1[i])
+					continue;
+
+				R_DrawSkyColumn(x + i, y1[i], y2[i], 1);
+			}
+			continue;
+		}
+
+		// Draw the first rows where not all 4 columns are active
+		for (int i = 0; i < 4; i++)
+		{
+			if (y1[i] < middle_y1)
+				R_DrawSkyColumn(x + i, y1[i], middle_y1, 1);
+		}
+
+		// Draw the area where all 4 columns are active
+		R_DrawSkyColumn(x, middle_y1, middle_y2, 4);
+
+		// Draw the last rows where not all 4 columns are active
+		for (int i = 0; i < 4; i++)
+		{
+			if (middle_y2 < y2[i])
+				R_DrawSkyColumn(x + i, middle_y2, y2[i], 1);
+		}
+	}
+
+	// The last unaligned columns:
+	for (int x = aligned_x2; x < x2; x++)
+	{
+		int y1 = uwal[x];
+		int y2 = dwal[x];
+		if (y2 <= y1)
+			continue;
+
+		R_DrawSkyColumn(x, y1, y2, 1);
+	}
+}
+
 static void R_DrawSky (visplane_t *pl)
 {
+	if (r_capsky)
+	{
+		R_DrawCapSky(pl);
+		return;
+	}
+
 	int x;
 	float swal;
 

src/textures/texture.cpp

@@ -45,6 +45,7 @@
 #include "v_video.h"
 #include "m_fixed.h"
 #include "textures/textures.h"
+#include "v_palette.h"
 
 typedef bool (*CheckFunc)(FileReader & file);
 typedef FTexture * (*CreateFunc)(FileReader & file, int lumpnum);
@@ -569,6 +570,78 @@ void FTexture::SetScaledSize(int fitwidth, int fitheight)
 	if (int(Scale.Y * fitheight) != Height) Scale.Y += (1 / 65536.);
 }
 
+//===========================================================================
+// 
+//	Gets the average color of a texture for use as a sky cap color
+//
+//===========================================================================
+
+namespace
+{
+	PalEntry averageColor(const DWORD *data, int size, int maxout)
+	{
+		int				i;
+		unsigned int	r, g, b;
+
+		// First clear them.
+		r = g = b = 0;
+		if (size == 0)
+		{
+			return PalEntry(255, 255, 255);
+		}
+		for (i = 0; i < size; i++)
+		{
+			r += BPART(data[i]);
+			g += GPART(data[i]);
+			b += RPART(data[i]);
+		}
+
+		r = r / size;
+		g = g / size;
+		b = b / size;
+
+		int maxv = MAX(MAX(r, g), b);
+
+		if (maxv && maxout)
+		{
+			r = Scale(r, maxout, maxv);
+			g = Scale(g, maxout, maxv);
+			b = Scale(b, maxout, maxv);
+		}
+		return PalEntry(255, r, g, b);
+	}
+}
+
+PalEntry FTexture::GetSWSkyCapColor(bool bottom)
+{
+	PalEntry col;
+	int w;
+	int h;
+
+	if (!bSWSkyColorDone)
+	{
+		bSWSkyColorDone = true;
+
+		FBitmap bitmap;
+		bitmap.Create(GetWidth(), GetHeight());
+		CopyTrueColorPixels(&bitmap, 0, 0);
+		int w = GetWidth();
+		int h = GetHeight();
+
+		const uint32_t *buffer = (const uint32_t *)bitmap.GetPixels();
+		if (buffer)
+		{
+			SWCeilingSkyColor = averageColor((DWORD *)buffer, w * MIN(30, h), 0);
+			if (h>30)
+			{
+				SWFloorSkyColor = averageColor(((DWORD *)buffer) + (h - 30)*w, w * 30, 0);
+			}
+			else SWFloorSkyColor = SWCeilingSkyColor;
+		}
+	}
+	return bottom ? SWFloorSkyColor : SWCeilingSkyColor;
+}
+
 
 FDummyTexture::FDummyTexture ()
 {

src/textures/textures.h

@@ -239,6 +239,7 @@ public:
 	}
 
 	void SetScaledSize(int fitwidth, int fitheight);
+	PalEntry GetSWSkyCapColor(bool bottom);
 
 	virtual void HackHack (int newheight);	// called by FMultipatchTexture to discover corrupt patches.
 
@@ -259,6 +260,11 @@ protected:
 		Rotations = other->Rotations;
 	}
 
+private:
+	bool bSWSkyColorDone = false;
+	PalEntry SWFloorSkyColor;
+	PalEntry SWCeilingSkyColor;
+
 public:
 	static void FlipSquareBlock (BYTE *block, int x, int y);
 	static void FlipSquareBlockRemap (BYTE *block, int x, int y, const BYTE *remap);

wadsrc/static/language.enu

@@ -1787,6 +1787,7 @@ DSPLYMNU_PICKUPFADE				= "Pickup Flash Intensity";
 DSPLYMNU_PALLETEHACK			= "DirectDraw palette hack"; // Not used
 DSPLYMNU_ATTACHEDSURFACES		= "Use attached surfaces"; // Not used
 DSPLYMNU_STRETCHSKY				= "Stretch short skies";
+DSPLYMNU_CAPSKY					= "Cap skies with solid color";
 DSPLYMNU_DRAWFUZZ				= "Use fuzz effect";
 DSPLYMNU_TRANSSOUL				= "Lost Soul translucency";
 DSPLYMNU_FAKECONTRAST			= "Use fake contrast";

wadsrc/static/menudef.txt

@@ -674,6 +674,7 @@ OptionMenu "VideoOptions"
 		//Option "$DSPLYMNU_ATTACHEDSURFACES", 	"vid_attachedsurfaces", "OnOff"
 	}
 	
+	Option "$DSPLYMNU_CAPSKY",					"r_capsky", "OnOff"
 	Option "$DSPLYMNU_STRETCHSKY",				"r_stretchsky", "OnOff"
 	Option "$DSPLYMNU_DRAWFUZZ",				"r_drawfuzz", "Fuzziness"
 	Slider "$DSPLYMNU_TRANSSOUL",				"transsouls", 0.25, 1.0, 0.05, 2