src/video/v9990/V9990PxConverter.cc at main · doomsdayone/openmsx

◆ main openmsx / src / video / v9990 / V9990PxConverter.cc

12.6 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw

#include "V9990PxConverter.hh"

#include "V9990.hh"
#include "V9990VRAM.hh"

#include "ScopedAssign.hh"
#include "narrow.hh"
#include "ranges.hh"

#include <algorithm>
#include <array>
#include <cassert>
#include <cstdint>
#include <optional>

namespace openmsx {

using Pixel = V9990P1Converter::Pixel;

V9990P1Converter::V9990P1Converter(V9990& vdp_, std::span</*const*/ Pixel, 64> palette64_)
	: vdp(vdp_), vram(vdp.getVRAM())
	, palette64(palette64_)
{
}

V9990P2Converter::V9990P2Converter(V9990& vdp_, std::span</*const*/ Pixel, 64> palette64_)
	: vdp(vdp_), vram(vdp.getVRAM()), palette64(palette64_)
{
}

struct P1Policy {
	static uint8_t readNameTable(const V9990VRAM& vram, unsigned addr) {
		return vram.readVRAMP1(addr);
	}
	static uint8_t readPatternTable(const V9990VRAM& vram, unsigned addr) {
		return vram.readVRAMP1(addr);
	}
	static uint8_t readSpriteAttr(const V9990VRAM& vram, unsigned addr) {
		return vram.readVRAMP1(addr);
	}
	static unsigned spritePatOfst(uint8_t spriteNo, uint8_t spriteY) {
		return (128 * ((spriteNo & 0xF0) + spriteY))
		     + (  8 *  (spriteNo & 0x0F));
	}
	static constexpr unsigned SCREEN_WIDTH = 256;
	static constexpr unsigned IMAGE_WIDTH = 2 * SCREEN_WIDTH;
	static constexpr unsigned NAME_CHARS = IMAGE_WIDTH / 8;
	static constexpr unsigned PATTERN_CHARS = SCREEN_WIDTH / 8;
};
struct P1BackgroundPolicy : P1Policy {
	static void draw1(
		std::span<const Pixel, 16> palette, Pixel* __restrict buffer,
		uint8_t* __restrict /*info*/, size_t p)
	{
		*buffer = palette[p];
	}
	static constexpr bool DRAW_BACKDROP = true;
};
struct P1ForegroundPolicy : P1Policy {
	static void draw1(
		std::span<const Pixel, 16> palette, Pixel* __restrict buffer,
		uint8_t* __restrict info, size_t p)
	{
		*info = bool(p);
		if (p) *buffer = palette[p];
	}
	static constexpr bool DRAW_BACKDROP = false;
};
struct P2Policy {
	static uint8_t readNameTable(const V9990VRAM& vram, unsigned addr) {
		return vram.readVRAMDirect(addr);
	}
	static uint8_t readPatternTable(const V9990VRAM& vram, unsigned addr) {
		return vram.readVRAMBx(addr);
	}
	static uint8_t readSpriteAttr(const V9990VRAM& vram, unsigned addr) {
		return vram.readVRAMDirect(addr);
	}
	static unsigned spritePatOfst(uint8_t spriteNo, uint8_t spriteY) {
		return (256 * (((spriteNo & 0xE0) >> 1) + spriteY))
		     + (  8 *  (spriteNo & 0x1F));
	}
	static void draw1(
		std::span<const Pixel, 16> palette, Pixel* __restrict buffer,
		uint8_t* __restrict info, size_t p)
	{
		*info = bool(p);
		*buffer = palette[p];
	}
	static constexpr bool DRAW_BACKDROP = true;
	static constexpr unsigned SCREEN_WIDTH = 512;
	static constexpr unsigned IMAGE_WIDTH = 2 * SCREEN_WIDTH;
	static constexpr unsigned NAME_CHARS = IMAGE_WIDTH / 8;
	static constexpr unsigned PATTERN_CHARS = SCREEN_WIDTH / 8;
};

template<typename Policy, bool ALIGNED>
static unsigned getPatternAddress(
	V9990VRAM& vram, unsigned nameAddr, unsigned patternBase, unsigned x, unsigned y)
{
	assert(!ALIGNED || ((x & 7) == 0));
	unsigned patternNum = (Policy::readNameTable(vram, nameAddr + 0) +
	                       Policy::readNameTable(vram, nameAddr + 1) * 256) & 0x1FFF;
	constexpr auto PATTERN_PITCH = Policy::PATTERN_CHARS * 8 * (8 / 2);
	unsigned x2 = (patternNum % Policy::PATTERN_CHARS) * 4 + (ALIGNED ? 0 : ((x & 7) / 2));
	unsigned y2 = (patternNum / Policy::PATTERN_CHARS) * PATTERN_PITCH + y;
	return patternBase + y2 + x2;
}

template<typename Policy>
static constexpr unsigned nextNameAddr(unsigned addr)
{
	constexpr auto MASK = (2 * Policy::NAME_CHARS) - 1;
	return (addr & ~MASK) | ((addr + 2) & MASK);
}

template<typename Policy, bool CHECK_WIDTH>
static void draw2(
	V9990VRAM& vram, std::span<const Pixel, 16> palette, Pixel* __restrict& buffer, uint8_t* __restrict& info,
	unsigned& address, int& width)
{
	uint8_t data = Policy::readPatternTable(vram, address++);
	Policy::draw1(palette, buffer + 0, info + 0, data >> 4);
	if (!CHECK_WIDTH || (width != 1)) {
		Policy::draw1(palette, buffer + 1, info + 1, data & 0x0F);
	}
	width  -= 2;
	buffer += 2;
	info   += 2;
}

template<typename Policy>
static void renderPattern(
	V9990VRAM& vram, Pixel* __restrict buffer, std::span<uint8_t> info_,
	Pixel bgCol, unsigned x, unsigned y,
	unsigned nameTable, unsigned patternBase,
	std::span</*const*/ Pixel, 16> palette0, std::span</*const*/ Pixel, 16> palette1)
{
	assert(x < Policy::IMAGE_WIDTH);
	auto width = narrow<int>(info_.size());
	if (width == 0) return;
	uint8_t* info = info_.data();

	std::optional<ScopedAssign<Pixel>> col0, col1; // optimized away when not used
	if constexpr (Policy::DRAW_BACKDROP) {
		// Speedup drawing by temporarily replacing palette index 0.
		// OK because palette0 and palette1 never partially overlap, IOW either:
		// - palette0 == palette1           (fully overlap)
		// - abs(palette0 - palette1) >= 16 (no overlap at all)
		col0.emplace(palette0[0], bgCol);
		col1.emplace(palette1[0], bgCol);
	}

	unsigned nameAddr = nameTable + (((y / 8) * Policy::NAME_CHARS + (x / 8)) * 2);
	y = (y & 7) * Policy::NAME_CHARS * 2;

	if (x & 7) {
		unsigned address = getPatternAddress<Policy, false>(vram, nameAddr, patternBase, x, y);
		if (x & 1) {
			uint8_t data = Policy::readPatternTable(vram, address);
			Policy::draw1((address & 1) ? palette1 : palette0, buffer, info, data & 0x0F);
			++address;
			++x;
			++buffer;
			++info;
			--width;
		}
		while ((x & 7) && (width > 0)) {
			draw2<Policy, true>(vram, (address & 1) ? palette1 : palette0, buffer, info, address, width);
			x += 2;
		}
		nameAddr = nextNameAddr<Policy>(nameAddr);
	}
	assert((x & 7) == 0 || (width <= 0));
	while ((width & ~7) > 0) {
		unsigned address = getPatternAddress<Policy, true>(vram, nameAddr, patternBase, x, y);
		draw2<Policy, false>(vram, palette0, buffer, info, address, width);
		draw2<Policy, false>(vram, palette1, buffer, info, address, width);
		draw2<Policy, false>(vram, palette0, buffer, info, address, width);
		draw2<Policy, false>(vram, palette1, buffer, info, address, width);
		nameAddr = nextNameAddr<Policy>(nameAddr);
	}
	assert(width < 8);
	if (width > 0) {
		unsigned address = getPatternAddress<Policy, true>(vram, nameAddr, patternBase, x, y);
		do {
			draw2<Policy, true>(vram, (address & 1) ? palette1 : palette0, buffer, info, address, width);
		} while (width > 0);
	}
}

template<typename Policy> // only used for P1
static void renderPattern2(
	V9990VRAM& vram, Pixel* buffer, std::span<uint8_t, 256> info, Pixel bgCol, unsigned width1, unsigned width2,
	unsigned displayAX, unsigned displayAY, unsigned nameA, unsigned patternA, std::span</*const*/ Pixel, 16> palA,
	unsigned displayBX, unsigned displayBY, unsigned nameB, unsigned patternB, std::span</*const*/ Pixel, 16> palB)
{
	renderPattern<Policy>(
		vram, buffer, subspan(info, 0, width1), bgCol,
		displayAX, displayAY, nameA, patternA, palA, palA);

	buffer += width1;
	width2 -= width1;
	displayBX = (displayBX + width1) & 511;

	renderPattern<Policy>(
		vram, buffer, subspan(info, width1, width2), bgCol,
		displayBX, displayBY, nameB, patternB, palB, palB);
}

template<typename Policy>
static void renderSprites(
	V9990VRAM& vram, unsigned spritePatternTable, std::span<const Pixel, 64> palette64,
	Pixel* __restrict buffer, std::span<uint8_t> info,
	int displayX, int displayEnd, unsigned displayY)
{
	constexpr unsigned spriteTable = 0x3FE00;

	// determine visible sprites
	std::array<int, 16 + 1> visibleSprites;
	int index = 0;
	int index_max = 16;
	for (auto sprite : xrange(125)) {
		unsigned spriteInfo = spriteTable + 4 * sprite;
		uint8_t spriteY = Policy::readSpriteAttr(vram, spriteInfo) + 1;
		auto posY = narrow_cast<uint8_t>(displayY - spriteY);
		if (posY < 16) {
			if (uint8_t attr = Policy::readSpriteAttr(vram, spriteInfo + 3);
			    attr & 0x10) {
				// Invisible sprites do contribute towards the
				// 16-sprites-per-line limit.
				index_max--;
			} else {
				visibleSprites[index++] = sprite;
			}
			if (index == index_max) break;
		}
	}
	visibleSprites[index] = -1;

	// actually draw sprites
	for (unsigned sprite = 0; visibleSprites[sprite] != -1; ++sprite) {
		unsigned addr = spriteTable + 4 * visibleSprites[sprite];
		uint8_t spriteAttr = Policy::readSpriteAttr(vram, addr + 3);
		bool front = (spriteAttr & 0x20) == 0;
		uint8_t level = front ? 2 : 1;
		int spriteX = Policy::readSpriteAttr(vram, addr + 2);
		spriteX += 256 * (spriteAttr & 0x03);
		if (spriteX > 1008) spriteX -= 1024; // hack X coord into -16..1008
		uint8_t spriteY  = Policy::readSpriteAttr(vram, addr + 0);
		uint8_t spriteNo = Policy::readSpriteAttr(vram, addr + 1);
		spriteY = narrow_cast<uint8_t>(displayY - (spriteY + 1));
		unsigned patAddr = spritePatternTable + Policy::spritePatOfst(spriteNo, spriteY);
		auto palette16 = subspan<16>(palette64, (spriteAttr >> 2) & 0x30);
		for (int x = 0; x < 16; x +=2) {
			auto draw = [&](int xPos, size_t p) {
				if ((displayX <= xPos) && (xPos < displayEnd)) {
					size_t xx = xPos - displayX;
					if (p) {
						if (info[xx] < level) {
							buffer[xx] = palette16[p];
						}
						info[xx] = 2; // also if back-sprite is behind foreground
					}
				}
			};
			uint8_t data = Policy::readPatternTable(vram, patAddr++);
			draw(spriteX + x + 0, data >> 4);
			draw(spriteX + x + 1, data & 0x0F);
		}
	}
}

void V9990P1Converter::convertLine(
	std::span<Pixel> buf, unsigned displayX, unsigned displayY,
	unsigned displayYA, unsigned displayYB, bool drawSprites)
{
	Pixel* __restrict linePtr = buf.data();
	auto displayWidth = narrow<unsigned>(buf.size());

	unsigned prioX = vdp.getPriorityControlX();
	unsigned prioY = vdp.getPriorityControlY();
	if (displayY >= prioY) prioX = 0;

	unsigned displayAX = (displayX + vdp.getScrollAX()) & 511;
	unsigned displayBX = (displayX + vdp.getScrollBX()) & 511;

	// Configurable 'roll' only applies to layer A.
	// Layer B always rolls at 512 lines.
	unsigned rollMask = vdp.getRollMask(0x1FF);
	unsigned scrollAY = vdp.getScrollAY();
	unsigned scrollBY = vdp.getScrollBY();
	unsigned scrollAYBase = scrollAY & ~rollMask & 0x1FF;
	unsigned displayAY = scrollAYBase + ((displayYA + scrollAY) & rollMask);
	unsigned displayBY =                 (displayYB + scrollBY) & 0x1FF;

	unsigned displayEnd = displayX + displayWidth;
	unsigned end1 = std::max(0, narrow<int>(std::min(prioX, displayEnd)) - narrow<int>(displayX));

	std::array<uint8_t, 256> info; // filled in later: 0->background, 1->foreground, 2->sprite (front or back)

	// background + backdrop color
	Pixel bgCol = palette64[vdp.getBackDropColor()];
	uint8_t offset = vdp.getPaletteOffset();
	auto palA = subspan<16>(palette64, (offset & 0x03) << 4);
	auto palB = subspan<16>(palette64, (offset & 0x0C) << 2);
	renderPattern2<P1BackgroundPolicy>( // does not yet fill-in 'info'
		vram, linePtr, /*dummy*/info, bgCol, end1, displayWidth,
		displayBX, displayBY, 0x7E000, 0x40000, palB,
		displayAX, displayAY, 0x7C000, 0x00000, palA);

	// foreground + fill-in 'info'
	assert(displayWidth <= 256);
	renderPattern2<P1ForegroundPolicy>( // fills 'info' with '0' or '1'
		vram, linePtr, info, bgCol, end1, displayWidth,
		displayAX, displayAY, 0x7C000, 0x00000, palA,
		displayBX, displayBY, 0x7E000, 0x40000, palB);

	// combined back+front sprite plane
	if (drawSprites) {
		unsigned spritePatternTable = vdp.getSpritePatternAddress(V9990DisplayMode::P1);
		renderSprites<P1Policy>( // uses and updates 'info'
			vram, spritePatternTable, palette64,
			linePtr, info, displayX, displayEnd, displayY);
	}
}

void V9990P2Converter::convertLine(
	std::span<Pixel> buf, unsigned displayX, unsigned displayY,
	unsigned displayYA, bool drawSprites)
{
	Pixel* __restrict linePtr = buf.data();
	auto displayWidth = narrow<unsigned>(buf.size());

	unsigned displayAX = (displayX + vdp.getScrollAX()) & 1023;

	unsigned scrollY = vdp.getScrollAY();
	unsigned rollMask = vdp.getRollMask(0x1FF);
	unsigned scrollYBase = scrollY & ~rollMask & 0x1FF;
	unsigned displayAY = scrollYBase + ((displayYA + scrollY) & rollMask);

	unsigned displayEnd = displayX + displayWidth;

	// image plane + backdrop color + fill-in 'info'
	assert(displayWidth <= 512);
	std::array<uint8_t, 512> info; // filled in later: 0->background, 1->foreground, 2->sprite (front or back)
	Pixel bgCol = palette64[vdp.getBackDropColor()];
	uint8_t offset = vdp.getPaletteOffset();
	auto palette0 = subspan<16>(palette64, (offset & 0x03) << 4);
	auto palette1 = subspan<16>(palette64, (offset & 0x0C) << 2);
	renderPattern<P2Policy>(
		vram, linePtr, subspan(info, 0, displayWidth), bgCol,
		displayAX, displayAY, 0x7C000, 0x00000, palette0, palette1);

	// combined back+front sprite plane
	if (drawSprites) {
		unsigned spritePatternTable = vdp.getSpritePatternAddress(V9990DisplayMode::P2);
		renderSprites<P2Policy>(
			vram, spritePatternTable, palette64,
			linePtr, info, displayX, displayEnd, displayY);
	}
}

} // namespace openmsx

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1	#include "V9990PxConverter.hh"
2
3	#include "V9990.hh"
4	#include "V9990VRAM.hh"
5
6	#include "ScopedAssign.hh"
7	#include "narrow.hh"
8	#include "ranges.hh"
9
10	#include <algorithm>
11	#include <array>
12	#include <cassert>
13	#include <cstdint>
14	#include <optional>
15
16	namespace openmsx {
17
18	using Pixel = V9990P1Converter::Pixel;
19
20	V9990P1Converter::V9990P1Converter(V9990& vdp_, std::span</const/ Pixel, 64> palette64_)
21	: vdp(vdp_), vram(vdp.getVRAM())
22	, palette64(palette64_)
23	{
24	}
25
26	V9990P2Converter::V9990P2Converter(V9990& vdp_, std::span</const/ Pixel, 64> palette64_)
27	: vdp(vdp_), vram(vdp.getVRAM()), palette64(palette64_)
28	{
29	}
30
31	struct P1Policy {
32	static uint8_t readNameTable(const V9990VRAM& vram, unsigned addr) {
33	return vram.readVRAMP1(addr);
34	}
35	static uint8_t readPatternTable(const V9990VRAM& vram, unsigned addr) {
36	return vram.readVRAMP1(addr);
37	}
38	static uint8_t readSpriteAttr(const V9990VRAM& vram, unsigned addr) {
39	return vram.readVRAMP1(addr);
40	}
41	static unsigned spritePatOfst(uint8_t spriteNo, uint8_t spriteY) {
42	return (128 * ((spriteNo & 0xF0) + spriteY))
43	+ ( 8 * (spriteNo & 0x0F));
44	}
45	static constexpr unsigned SCREEN_WIDTH = 256;
46	static constexpr unsigned IMAGE_WIDTH = 2 * SCREEN_WIDTH;
47	static constexpr unsigned NAME_CHARS = IMAGE_WIDTH / 8;
48	static constexpr unsigned PATTERN_CHARS = SCREEN_WIDTH / 8;
49	};
50	struct P1BackgroundPolicy : P1Policy {
51	static void draw1(
52	std::span<const Pixel, 16> palette, Pixel* __restrict buffer,
53	uint8_t* __restrict /info/, size_t p)
54	{
55	*buffer = palette[p];
56	}
57	static constexpr bool DRAW_BACKDROP = true;
58	};
59	struct P1ForegroundPolicy : P1Policy {
60	static void draw1(
61	std::span<const Pixel, 16> palette, Pixel* __restrict buffer,
62	uint8_t* __restrict info, size_t p)
63	{
64	*info = bool(p);
65	if (p) *buffer = palette[p];
66	}
67	static constexpr bool DRAW_BACKDROP = false;
68	};
69	struct P2Policy {
70	static uint8_t readNameTable(const V9990VRAM& vram, unsigned addr) {
71	return vram.readVRAMDirect(addr);
72	}
73	static uint8_t readPatternTable(const V9990VRAM& vram, unsigned addr) {
74	return vram.readVRAMBx(addr);
75	}
76	static uint8_t readSpriteAttr(const V9990VRAM& vram, unsigned addr) {
77	return vram.readVRAMDirect(addr);
78	}
79	static unsigned spritePatOfst(uint8_t spriteNo, uint8_t spriteY) {
80	return (256 * (((spriteNo & 0xE0) >> 1) + spriteY))
81	+ ( 8 * (spriteNo & 0x1F));
82	}
83	static void draw1(
84	std::span<const Pixel, 16> palette, Pixel* __restrict buffer,
85	uint8_t* __restrict info, size_t p)
86	{
87	*info = bool(p);
88	*buffer = palette[p];
89	}
90	static constexpr bool DRAW_BACKDROP = true;
91	static constexpr unsigned SCREEN_WIDTH = 512;
92	static constexpr unsigned IMAGE_WIDTH = 2 * SCREEN_WIDTH;
93	static constexpr unsigned NAME_CHARS = IMAGE_WIDTH / 8;
94	static constexpr unsigned PATTERN_CHARS = SCREEN_WIDTH / 8;
95	};
96
97	template<typename Policy, bool ALIGNED>
98	static unsigned getPatternAddress(
99	V9990VRAM& vram, unsigned nameAddr, unsigned patternBase, unsigned x, unsigned y)
100	{
101	assert(!ALIGNED \|\| ((x & 7) == 0));
102	unsigned patternNum = (Policy::readNameTable(vram, nameAddr + 0) +
103	Policy::readNameTable(vram, nameAddr + 1) * 256) & 0x1FFF;
104	constexpr auto PATTERN_PITCH = Policy::PATTERN_CHARS * 8 * (8 / 2);
105	unsigned x2 = (patternNum % Policy::PATTERN_CHARS) * 4 + (ALIGNED ? 0 : ((x & 7) / 2));
106	unsigned y2 = (patternNum / Policy::PATTERN_CHARS) * PATTERN_PITCH + y;
107	return patternBase + y2 + x2;
108	}
109
110	template<typename Policy>
111	static constexpr unsigned nextNameAddr(unsigned addr)
112	{
113	constexpr auto MASK = (2 * Policy::NAME_CHARS) - 1;
114	return (addr & ~MASK) \| ((addr + 2) & MASK);
115	}
116
117	template<typename Policy, bool CHECK_WIDTH>
118	static void draw2(
119	V9990VRAM& vram, std::span<const Pixel, 16> palette, Pixel* __restrict& buffer, uint8_t* __restrict& info,
120	unsigned& address, int& width)
121	{
122	uint8_t data = Policy::readPatternTable(vram, address++);
123	Policy::draw1(palette, buffer + 0, info + 0, data >> 4);
124	if (!CHECK_WIDTH \|\| (width != 1)) {
125	Policy::draw1(palette, buffer + 1, info + 1, data & 0x0F);
126	}
127	width -= 2;
128	buffer += 2;
129	info += 2;
130	}
131
132	template<typename Policy>
133	static void renderPattern(
134	V9990VRAM& vram, Pixel* __restrict buffer, std::span<uint8_t> info_,
135	Pixel bgCol, unsigned x, unsigned y,
136	unsigned nameTable, unsigned patternBase,
137	std::span</const/ Pixel, 16> palette0, std::span</const/ Pixel, 16> palette1)
138	{
139	assert(x < Policy::IMAGE_WIDTH);
140	auto width = narrow<int>(info_.size());
141	if (width == 0) return;
142	uint8_t* info = info_.data();
143
144	std::optional<ScopedAssign<Pixel>> col0, col1; // optimized away when not used
145	if constexpr (Policy::DRAW_BACKDROP) {
146	// Speedup drawing by temporarily replacing palette index 0.
147	// OK because palette0 and palette1 never partially overlap, IOW either:
148	// - palette0 == palette1 (fully overlap)
149	// - abs(palette0 - palette1) >= 16 (no overlap at all)
150	col0.emplace(palette0[0], bgCol);
151	col1.emplace(palette1[0], bgCol);
152	}
153
154	unsigned nameAddr = nameTable + (((y / 8) * Policy::NAME_CHARS + (x / 8)) * 2);
155	y = (y & 7) * Policy::NAME_CHARS * 2;
156
157	if (x & 7) {
158	unsigned address = getPatternAddress<Policy, false>(vram, nameAddr, patternBase, x, y);
159	if (x & 1) {
160	uint8_t data = Policy::readPatternTable(vram, address);
161	Policy::draw1((address & 1) ? palette1 : palette0, buffer, info, data & 0x0F);
162	++address;
163	++x;
164	++buffer;
165	++info;
166	--width;
167	}
168	while ((x & 7) && (width > 0)) {
169	draw2<Policy, true>(vram, (address & 1) ? palette1 : palette0, buffer, info, address, width);
170	x += 2;
171	}
172	nameAddr = nextNameAddr<Policy>(nameAddr);
173	}
174	assert((x & 7) == 0 \|\| (width <= 0));
175	while ((width & ~7) > 0) {
176	unsigned address = getPatternAddress<Policy, true>(vram, nameAddr, patternBase, x, y);
177	draw2<Policy, false>(vram, palette0, buffer, info, address, width);
178	draw2<Policy, false>(vram, palette1, buffer, info, address, width);
179	draw2<Policy, false>(vram, palette0, buffer, info, address, width);
180	draw2<Policy, false>(vram, palette1, buffer, info, address, width);
181	nameAddr = nextNameAddr<Policy>(nameAddr);
182	}
183	assert(width < 8);
184	if (width > 0) {
185	unsigned address = getPatternAddress<Policy, true>(vram, nameAddr, patternBase, x, y);
186	do {
187	draw2<Policy, true>(vram, (address & 1) ? palette1 : palette0, buffer, info, address, width);
188	} while (width > 0);
189	}
190	}
191
192	template<typename Policy> // only used for P1
193	static void renderPattern2(
194	V9990VRAM& vram, Pixel* buffer, std::span<uint8_t, 256> info, Pixel bgCol, unsigned width1, unsigned width2,
195	unsigned displayAX, unsigned displayAY, unsigned nameA, unsigned patternA, std::span</const/ Pixel, 16> palA,
196	unsigned displayBX, unsigned displayBY, unsigned nameB, unsigned patternB, std::span</const/ Pixel, 16> palB)
197	{
198	renderPattern<Policy>(
199	vram, buffer, subspan(info, 0, width1), bgCol,
200	displayAX, displayAY, nameA, patternA, palA, palA);
201
202	buffer += width1;
203	width2 -= width1;
204	displayBX = (displayBX + width1) & 511;
205
206	renderPattern<Policy>(
207	vram, buffer, subspan(info, width1, width2), bgCol,
208	displayBX, displayBY, nameB, patternB, palB, palB);
209	}
210
211	template<typename Policy>
212	static void renderSprites(
213	V9990VRAM& vram, unsigned spritePatternTable, std::span<const Pixel, 64> palette64,
214	Pixel* __restrict buffer, std::span<uint8_t> info,
215	int displayX, int displayEnd, unsigned displayY)
216	{
217	constexpr unsigned spriteTable = 0x3FE00;
218
219	// determine visible sprites
220	std::array<int, 16 + 1> visibleSprites;
221	int index = 0;
222	int index_max = 16;
223	for (auto sprite : xrange(125)) {
224	unsigned spriteInfo = spriteTable + 4 * sprite;
225	uint8_t spriteY = Policy::readSpriteAttr(vram, spriteInfo) + 1;
226	auto posY = narrow_cast<uint8_t>(displayY - spriteY);
227	if (posY < 16) {
228	if (uint8_t attr = Policy::readSpriteAttr(vram, spriteInfo + 3);
229	attr & 0x10) {
230	// Invisible sprites do contribute towards the
231	// 16-sprites-per-line limit.
232	index_max--;
233	} else {
234	visibleSprites[index++] = sprite;
235	}
236	if (index == index_max) break;
237	}
238	}
239	visibleSprites[index] = -1;
240
241	// actually draw sprites
242	for (unsigned sprite = 0; visibleSprites[sprite] != -1; ++sprite) {
243	unsigned addr = spriteTable + 4 * visibleSprites[sprite];
244	uint8_t spriteAttr = Policy::readSpriteAttr(vram, addr + 3);
245	bool front = (spriteAttr & 0x20) == 0;
246	uint8_t level = front ? 2 : 1;
247	int spriteX = Policy::readSpriteAttr(vram, addr + 2);
248	spriteX += 256 * (spriteAttr & 0x03);
249	if (spriteX > 1008) spriteX -= 1024; // hack X coord into -16..1008
250	uint8_t spriteY = Policy::readSpriteAttr(vram, addr + 0);
251	uint8_t spriteNo = Policy::readSpriteAttr(vram, addr + 1);
252	spriteY = narrow_cast<uint8_t>(displayY - (spriteY + 1));
253	unsigned patAddr = spritePatternTable + Policy::spritePatOfst(spriteNo, spriteY);
254	auto palette16 = subspan<16>(palette64, (spriteAttr >> 2) & 0x30);
255	for (int x = 0; x < 16; x +=2) {
256	auto draw = [&](int xPos, size_t p) {
257	if ((displayX <= xPos) && (xPos < displayEnd)) {
258	size_t xx = xPos - displayX;
259	if (p) {
260	if (info[xx] < level) {
261	buffer[xx] = palette16[p];
262	}
263	info[xx] = 2; // also if back-sprite is behind foreground
264	}
265	}
266	};
267	uint8_t data = Policy::readPatternTable(vram, patAddr++);
268	draw(spriteX + x + 0, data >> 4);
269	draw(spriteX + x + 1, data & 0x0F);
270	}
271	}
272	}
273
274	void V9990P1Converter::convertLine(
275	std::span<Pixel> buf, unsigned displayX, unsigned displayY,
276	unsigned displayYA, unsigned displayYB, bool drawSprites)
277	{
278	Pixel* __restrict linePtr = buf.data();
279	auto displayWidth = narrow<unsigned>(buf.size());
280
281	unsigned prioX = vdp.getPriorityControlX();
282	unsigned prioY = vdp.getPriorityControlY();
283	if (displayY >= prioY) prioX = 0;
284
285	unsigned displayAX = (displayX + vdp.getScrollAX()) & 511;
286	unsigned displayBX = (displayX + vdp.getScrollBX()) & 511;
287
288	// Configurable 'roll' only applies to layer A.
289	// Layer B always rolls at 512 lines.
290	unsigned rollMask = vdp.getRollMask(0x1FF);
291	unsigned scrollAY = vdp.getScrollAY();
292	unsigned scrollBY = vdp.getScrollBY();
293	unsigned scrollAYBase = scrollAY & ~rollMask & 0x1FF;
294	unsigned displayAY = scrollAYBase + ((displayYA + scrollAY) & rollMask);
295	unsigned displayBY = (displayYB + scrollBY) & 0x1FF;
296
297	unsigned displayEnd = displayX + displayWidth;
298	unsigned end1 = std::max(0, narrow<int>(std::min(prioX, displayEnd)) - narrow<int>(displayX));
299
300	std::array<uint8_t, 256> info; // filled in later: 0->background, 1->foreground, 2->sprite (front or back)
301
302	// background + backdrop color
303	Pixel bgCol = palette64[vdp.getBackDropColor()];
304	uint8_t offset = vdp.getPaletteOffset();
305	auto palA = subspan<16>(palette64, (offset & 0x03) << 4);
306	auto palB = subspan<16>(palette64, (offset & 0x0C) << 2);
307	renderPattern2<P1BackgroundPolicy>( // does not yet fill-in 'info'
308	vram, linePtr, /dummy/info, bgCol, end1, displayWidth,
309	displayBX, displayBY, 0x7E000, 0x40000, palB,
310	displayAX, displayAY, 0x7C000, 0x00000, palA);
311
312	// foreground + fill-in 'info'
313	assert(displayWidth <= 256);
314	renderPattern2<P1ForegroundPolicy>( // fills 'info' with '0' or '1'
315	vram, linePtr, info, bgCol, end1, displayWidth,
316	displayAX, displayAY, 0x7C000, 0x00000, palA,
317	displayBX, displayBY, 0x7E000, 0x40000, palB);
318
319	// combined back+front sprite plane
320	if (drawSprites) {
321	unsigned spritePatternTable = vdp.getSpritePatternAddress(V9990DisplayMode::P1);
322	renderSprites<P1Policy>( // uses and updates 'info'
323	vram, spritePatternTable, palette64,
324	linePtr, info, displayX, displayEnd, displayY);
325	}
326	}
327
328	void V9990P2Converter::convertLine(
329	std::span<Pixel> buf, unsigned displayX, unsigned displayY,
330	unsigned displayYA, bool drawSprites)
331	{
332	Pixel* __restrict linePtr = buf.data();
333	auto displayWidth = narrow<unsigned>(buf.size());
334
335	unsigned displayAX = (displayX + vdp.getScrollAX()) & 1023;
336
337	unsigned scrollY = vdp.getScrollAY();
338	unsigned rollMask = vdp.getRollMask(0x1FF);
339	unsigned scrollYBase = scrollY & ~rollMask & 0x1FF;
340	unsigned displayAY = scrollYBase + ((displayYA + scrollY) & rollMask);
341
342	unsigned displayEnd = displayX + displayWidth;
343
344	// image plane + backdrop color + fill-in 'info'
345	assert(displayWidth <= 512);
346	std::array<uint8_t, 512> info; // filled in later: 0->background, 1->foreground, 2->sprite (front or back)
347	Pixel bgCol = palette64[vdp.getBackDropColor()];
348	uint8_t offset = vdp.getPaletteOffset();
349	auto palette0 = subspan<16>(palette64, (offset & 0x03) << 4);
350	auto palette1 = subspan<16>(palette64, (offset & 0x0C) << 2);
351	renderPattern<P2Policy>(
352	vram, linePtr, subspan(info, 0, displayWidth), bgCol,
353	displayAX, displayAY, 0x7C000, 0x00000, palette0, palette1);
354
355	// combined back+front sprite plane
356	if (drawSprites) {
357	unsigned spritePatternTable = vdp.getSpritePatternAddress(V9990DisplayMode::P2);
358	renderSprites<P2Policy>(
359	vram, spritePatternTable, palette64,
360	linePtr, info, displayX, displayEnd, displayY);
361	}
362	}
363
364	} // namespace openmsx

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