Put two of the WinCE downscalers into graphics/scaler/downscaler*, so that they can be used by multiple backends (more could be added as needed)

svn-id: r45974

3 files changed, 327 insertions, 0 deletions

diff --git a/graphics/scaler/downscaler.cpp b/graphics/scaler/downscaler.cpp
new file mode 100644
index 0000000000..21ba1ce36d
--- /dev/null
+++ b/graphics/scaler/downscaler.cpp
@@ -0,0 +1,96 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+#include "graphics/scaler/downscaler.h"
+#include "graphics/scaler/intern.h"
+
+#ifdef ARM
+extern "C" {
+	void DownscaleAllByHalfARM(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height, int mask, int round);
+}
+
+void DownscaleAllByHalf(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) {
+	// Rounding constants and masks used for different pixel formats
+	static const int roundingconstants[] = { 0x00200802, 0x00201002 };
+	static const int redbluegreenMasks[] = { 0x03E07C1F, 0x07E0F81F };
+
+	const int maskUsed = (gBitFormat == 565);
+	DownscaleAllByHalfARM(srcPtr, srcPitch, dstPtr, dstPitch, width, height, redbluegreenMasks[maskUsed], roundingconstants[maskUsed]);
+}
+
+#else
+
+template<int bitFormat>
+void DownscaleAllByHalfTemplate(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) {
+	uint8 *work;
+	uint16 srcPitch16 = (uint16)(srcPitch / sizeof(uint16));
+
+	while ((height -= 2) >= 0) {
+		work = dstPtr;
+
+		for (int i=0; i<width; i+=2) {
+			// Another lame filter attempt :)
+			uint16 color1 = *(((const uint16 *)srcPtr) + i);
+			uint16 color2 = *(((const uint16 *)srcPtr) + (i + 1));
+			uint16 color3 = *(((const uint16 *)srcPtr) + (i + srcPitch16));
+			uint16 color4 = *(((const uint16 *)srcPtr) + (i + srcPitch16 + 1));
+			*(((uint16 *)work) + 0) = interpolate16_1_1_1_1<Graphics::ColorMasks<bitFormat> >(color1, color2, color3, color4);
+
+			work += sizeof(uint16);
+		}
+		srcPtr += 2 * srcPitch;
+		dstPtr += dstPitch;
+	}
+}
+MAKE_WRAPPER(DownscaleAllByHalf)
+
+#endif
+
+
+/**
+ * This filter (down)scales the source image horizontally by a factor of 1/2.
+ * For example, a 320x200 image is scaled to 160x200.
+ */
+template<int bitFormat>
+void DownscaleHorizByHalfTemplate(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) {
+	uint16 *work;
+
+	if (!height)
+		return;
+
+	// Various casts below go via (void *) to avoid warning. This is
+	// safe as these are all even addresses.
+	while (height--) {
+		work = (uint16 *)(void *)dstPtr;
+
+		for (int i = 0; i < width; i += 2) {
+			uint16 color1 = *(((const uint16 *)(const void *)srcPtr) + i);
+			uint16 color2 = *(((const uint16 *)(const void *)srcPtr) + (i + 1));
+			*work++ = interpolate32_1_1<bitFormat>(color1, color2);
+		}
+		srcPtr += srcPitch;
+		dstPtr += dstPitch;
+	}
+}
+MAKE_WRAPPER(DownscaleHorizByHalf)
diff --git a/graphics/scaler/downscaler.h b/graphics/scaler/downscaler.h
new file mode 100644
index 0000000000..115ad945e5
--- /dev/null
+++ b/graphics/scaler/downscaler.h
@@ -0,0 +1,44 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#ifndef GRAPHICS_SCALER_DOWNSCALER_H
+#define GRAPHICS_SCALER_DOWNSCALER_H
+
+#include "common/scummsys.h"
+#include "graphics/scaler.h"
+
+/**
+ * This filter (down)scales the source image by a factor of 1/2.
+ * For example, a 320x200 image is scaled to 160x100.
+ */
+DECLARE_SCALER(DownscaleAllByHalf);
+
+/**
+ * This filter (down)scales the source image horizontally by a factor of 1/2.
+ * For example, a 320x200 image is scaled to 160x200.
+ */
+DECLARE_SCALER(DownscaleHorizByHalf);
+
+#endif
diff --git a/graphics/scaler/downscalerARM.s b/graphics/scaler/downscalerARM.s
new file mode 100644
index 0000000000..3422e68762
--- /dev/null
+++ b/graphics/scaler/downscalerARM.s
@@ -0,0 +1,187 @@
+@ ScummVM - Graphic Adventure Engine
+@
+@ ScummVM is the legal property of its developers, whose names
+@ are too numerous to list here. Please refer to the COPYRIGHT
+@ file distributed with this source distribution.
+@
+@ This program is free software; you can redistribute it and/or
+@ modify it under the terms of the GNU General Public License
+@ as published by the Free Software Foundation; either version 2
+@ of the License, or (at your option) any later version.
+@
+@ This program is distributed in the hope that it will be useful,
+@ but WITHOUT ANY WARRANTY; without even the implied warranty of
+@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+@ GNU General Public License for more details.
+@
+@ You should have received a copy of the GNU General Public License
+@ along with this program; if not, write to the Free Software
+@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+@
+@ $URL$
+@ $Id$
+@
+@ @author Robin Watts (robin@wss.co.uk)
+
+	.text
+
+	.global	DownscaleAllByHalfARM
+
+	@ ARM implementation of DownscaleAllByHalf scaler.
+	@ Scales a width x height block of 16bpp pixels from srcPtr to
+	@ dstPtr. srcPitch and dstPitch identify how to reach subsequent
+	@ lines. redblueMask and round allow for one routine to do both
+	@ 565 and 555 formats.
+DownscaleAllByHalfARM:
+	@ r0 = srcPtr
+	@ r1 = srcPitch
+	@ r2 = dstPtr
+	@ r3 = dstPitch
+	MOV	r12,r13
+	STMFD	r13!,{r4-r11,r14}
+	LDMIA	r12,{r4-r7}
+	@ r4 = width
+	@ r5 = height
+	@ r6 = redblueMask
+	@ r7 = round
+
+	SUB	r3,r3,r4		@ dstPitch -= width
+	SUBS	r5,r5,#2		@ while ((height-=2) >= 0)
+	BLT	end
+height_loop:
+
+        SUBS	r11, r4, #8		@ r11= width_minus_8
+	BLT	thin
+
+width_loop:
+	@ unroll loop 4 times here
+	LDRH	r8,[r0],r1		@ r8 = A = srcPtr[0]
+	LDRH	r9,[r0],#2		@ r9 = C = srcPtr[dstPitch]
+	LDRH	r12,[r0],-r1		@ r12= D = srcPtr[dstPitch+2]
+	LDRH	r14,[r0],#2		@ r14= B = srcPtr[2]
+
+	ORR	r8, r8, r8, LSL #16	@ r8 = b | g | r | b | g | r
+	ORR	r9, r9, r9, LSL #16	@ r9 = b | g | r | b | g | r
+	ORR	r12,r12,r12,LSL #16	@ r12= b | g | r | b | g | r
+	ORR	r14,r14,r14,LSL #16	@ r14= b | g | r | b | g | r
+	AND	r8, r8, r6		@ r8 = 0 | g | 0 | b | 0 | r
+	AND	r9, r9, r6		@ r9 = 0 | g | 0 | b | 0 | r
+	AND	r12,r12,r6		@ r12= 0 | g | 0 | b | 0 | r
+	AND	r14,r14,r6		@ r14= 0 | g | 0 | b | 0 | r
+	ADD	r8, r8, r9
+	ADD	r8, r8, r12
+	ADD	r8, r8, r14
+	ADD	r8, r8, r7		@ r8 = summed pixels + rounding
+	AND	r8, r6, r8, LSR #2	@ r8 = 0 | g | 0 | b | 0 | r
+	ORR	r10,r8, r8, LSR #16	@ r10= 0 | g | 0 | b | g | r
+
+	LDRH	r8,[r0],r1		@ r8 = A = srcPtr[0]
+	LDRH	r9,[r0],#2		@ r9 = C = srcPtr[dstPitch]
+	LDRH	r12,[r0],-r1		@ r12= D = srcPtr[dstPitch+2]
+	LDRH	r14,[r0],#2		@ r14= B = srcPtr[2]
+
+	STRH	r10,[r2],#2		@ *dstPtr++
+
+	ORR	r8, r8, r8, LSL #16	@ r8 = b | g | r | b | g | r
+	ORR	r9, r9, r9, LSL #16	@ r9 = b | g | r | b | g | r
+	ORR	r12,r12,r12,LSL #16	@ r12= b | g | r | b | g | r
+	ORR	r14,r14,r14,LSL #16	@ r14= b | g | r | b | g | r
+	AND	r8, r8, r6		@ r8 = 0 | g | 0 | b | 0 | r
+	AND	r9, r9, r6		@ r9 = 0 | g | 0 | b | 0 | r
+	AND	r12,r12,r6		@ r12= 0 | g | 0 | b | 0 | r
+	AND	r14,r14,r6		@ r14= 0 | g | 0 | b | 0 | r
+	ADD	r8, r8, r9
+	ADD	r8, r8, r12
+	ADD	r8, r8, r14
+	ADD	r8, r8, r7		@ r8 = summed pixels + rounding
+	AND	r8, r6, r8, LSR #2	@ r8 = 0 | g | 0 | b | 0 | r
+	ORR	r10,r8, r8, LSR #16	@ r10= 0 | g | 0 | b | g | r
+
+	LDRH	r8,[r0],r1		@ r8 = A = srcPtr[0]
+	LDRH	r9,[r0],#2		@ r9 = C = srcPtr[dstPitch]
+	LDRH	r12,[r0],-r1		@ r12= D = srcPtr[dstPitch+2]
+	LDRH	r14,[r0],#2		@ r14= B = srcPtr[2]
+
+	STRH	r10,[r2],#2		@ *dstPtr++
+
+	ORR	r8, r8, r8, LSL #16	@ r8 = b | g | r | b | g | r
+	ORR	r9, r9, r9, LSL #16	@ r9 = b | g | r | b | g | r
+	ORR	r12,r12,r12,LSL #16	@ r12= b | g | r | b | g | r
+	ORR	r14,r14,r14,LSL #16	@ r14= b | g | r | b | g | r
+	AND	r8, r8, r6		@ r8 = 0 | g | 0 | b | 0 | r
+	AND	r9, r9, r6		@ r9 = 0 | g | 0 | b | 0 | r
+	AND	r12,r12,r6		@ r12= 0 | g | 0 | b | 0 | r
+	AND	r14,r14,r6		@ r14= 0 | g | 0 | b | 0 | r
+	ADD	r8, r8, r9
+	ADD	r8, r8, r12
+	ADD	r8, r8, r14
+	ADD	r8, r8, r7		@ r8 = summed pixels + rounding
+	AND	r8, r6, r8, LSR #2	@ r8 = 0 | g | 0 | b | 0 | r
+	ORR	r10,r8, r8, LSR #16	@ r10= 0 | g | 0 | b | g | r
+
+	LDRH	r8,[r0],r1		@ r8 = A = srcPtr[0]
+	LDRH	r9,[r0],#2		@ r9 = C = srcPtr[dstPitch]
+	LDRH	r12,[r0],-r1		@ r12= D = srcPtr[dstPitch+2]
+	LDRH	r14,[r0],#2		@ r14= B = srcPtr[2]
+
+	STRH	r10,[r2],#2		@ *dstPtr++
+
+	ORR	r8, r8, r8, LSL #16	@ r8 = b | g | r | b | g | r
+	ORR	r9, r9, r9, LSL #16	@ r9 = b | g | r | b | g | r
+	ORR	r12,r12,r12,LSL #16	@ r12= b | g | r | b | g | r
+	ORR	r14,r14,r14,LSL #16	@ r14= b | g | r | b | g | r
+	AND	r8, r8, r6		@ r8 = 0 | g | 0 | b | 0 | r
+	AND	r9, r9, r6		@ r9 = 0 | g | 0 | b | 0 | r
+	AND	r12,r12,r6		@ r12= 0 | g | 0 | b | 0 | r
+	AND	r14,r14,r6		@ r14= 0 | g | 0 | b | 0 | r
+	ADD	r8, r8, r9
+	ADD	r8, r8, r12
+	ADD	r8, r8, r14
+	ADD	r8, r8, r7		@ r8 = summed pixels + rounding
+	AND	r8, r6, r8, LSR #2	@ r8 = 0 | g | 0 | b | 0 | r
+	ORR	r10, r8, r8, LSR #16	@ r8 = 0 | g | 0 | b | g | r
+
+	STRH	r10,[r2],#2		@ *dstPtr++
+
+	SUBS	r11,r11,#8		@ width_minus_8 -= 8
+	BGE	width_loop		@ (width_minus_8 >= 0) => do 8+ more
+
+thin:
+	ADDS	r11,r11,#8		@ r11= width
+	BEQ	width_end		@ if no more left to do, then bail
+thin_lp:
+	@ single output pixels done in this bit
+	LDRH	r8,[r0],r1		@ r8 = A = srcPtr[0]
+	LDRH	r9,[r0],#2		@ r9 = C = srcPtr[dstPitch]
+	LDRH	r12,[r0],-r1		@ r12= D = srcPtr[dstPitch+2]
+	LDRH	r14,[r0],#2		@ r14= B = srcPtr[2]
+
+	ORR	r8, r8, r8, LSL #16	@ r8 = b | g | r | b | g | r
+	ORR	r9, r9, r9, LSL #16	@ r9 = b | g | r | b | g | r
+	ORR	r12,r12,r12,LSL #16	@ r12= b | g | r | b | g | r
+	ORR	r14,r14,r14,LSL #16	@ r14= b | g | r | b | g | r
+	AND	r8, r8, r6		@ r8 = 0 | g | 0 | b | 0 | r
+	AND	r9, r9, r6		@ r9 = 0 | g | 0 | b | 0 | r
+	AND	r12,r12,r6		@ r12= 0 | g | 0 | b | 0 | r
+	AND	r14,r14,r6		@ r14= 0 | g | 0 | b | 0 | r
+	ADD	r8, r8, r9
+	ADD	r8, r8, r12
+	ADD	r8, r8, r14
+	ADD	r8, r8, r7		@ r8 = summed pixels + rounding
+	AND	r8, r6, r8, LSR #2	@ r8 = 0 | g | 0 | b | 0 | r
+	ORR	r8, r8, r8, LSR #16	@ r8 = 0 | g | 0 | b | g | r
+
+	STRH	r8,[r2],#2		@ *dstPtr++
+
+	SUBS	r11,r11,#2
+	BGT	thin_lp
+width_end:
+	ADD	r2,r2,r3		@ dstPtr += dstPitch
+	ADD	r0,r0,r1,LSL #1		@ srcPtr += 2*srcPitch
+	SUB	r0,r0,r4,LSL #1		@ srcPtr -= 2*width
+
+	SUBS	r5,r5,#2
+	BGE	height_loop
+
+end:
+	LDMFD	r13!,{r4-r11,PC}