mgba/src/gba/renderers/software-bg.c

/* Copyright (c) 2013-2015 Jeffrey Pfau
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "gba/renderers/software-private.h"

#include <mgba/core/interface.h>
#include <mgba/internal/gba/gba.h>

#define BACKGROUND_BITMAP_ITERATE(W, H)                     \
	x += background->dx;                                    \
	y += background->dy;                                    \
                                                            \
	if (x < 0 || y < 0 || (x >> 8) >= W || (y >> 8) >= H) { \
		continue;                                           \
	} else {                                                \
		localX = x;                                         \
		localY = y;                                         \
	}

#define MODE_2_COORD_OVERFLOW \
	localX = x & (sizeAdjusted - 1); \
	localY = y & (sizeAdjusted - 1); \

#define MODE_2_COORD_NO_OVERFLOW \
	if ((x | y) & ~(sizeAdjusted - 1)) { \
		continue; \
	} \
	localX = x; \
	localY = y;

#define MODE_2_NO_MOSAIC(COORD) \
	COORD \
	uint32_t screenBase = background->screenBase + (localX >> 11) + (((localY >> 7) & 0x7F0) << background->size); \
	mapData = ((uint8_t*) renderer->d.vramBG[screenBase >> VRAM_BLOCK_OFFSET])[screenBase & VRAM_BLOCK_MASK]; \
	uint32_t charBase = background->charBase + (mapData << 6) + ((localY & 0x700) >> 5) + ((localX & 0x700) >> 8); \
	pixelData = ((uint8_t*) renderer->d.vramBG[charBase >> VRAM_BLOCK_OFFSET])[charBase & VRAM_BLOCK_MASK]; \

#define MODE_2_MOSAIC(COORD) \
		if (!mosaicWait) { \
			MODE_2_NO_MOSAIC(COORD)	\
			mosaicWait = mosaicH; \
		} else { \
			--mosaicWait; \
		}

#define MODE_2_LOOP(MOSAIC, COORD, BLEND, OBJWIN) \
	for (outX = renderer->start; outX < renderer->end; ++outX) { \
		x += background->dx; \
		y += background->dy; \
		\
		uint32_t current = renderer->row[outX]; \
		MOSAIC(COORD) \
		if (pixelData) { \
			COMPOSITE_256_ ## OBJWIN (BLEND, 0); \
		} \
	}

#define DRAW_BACKGROUND_MODE_2(BLEND, OBJWIN) \
	if (background->overflow) { \
		if (mosaicH > 1) { \
			MODE_2_LOOP(MODE_2_MOSAIC, MODE_2_COORD_OVERFLOW, BLEND, OBJWIN); \
		} else { \
			MODE_2_LOOP(MODE_2_NO_MOSAIC, MODE_2_COORD_OVERFLOW, BLEND, OBJWIN); \
		} \
	} else { \
		if (mosaicH > 1) { \
			MODE_2_LOOP(MODE_2_MOSAIC, MODE_2_COORD_NO_OVERFLOW, BLEND, OBJWIN); \
		} else { \
			MODE_2_LOOP(MODE_2_NO_MOSAIC, MODE_2_COORD_NO_OVERFLOW, BLEND, OBJWIN); \
		} \
	}

void GBAVideoSoftwareRendererDrawBackgroundMode2(struct GBAVideoSoftwareRenderer* renderer, struct GBAVideoSoftwareBackground* background, int inY) {
	int sizeAdjusted = 0x8000 << background->size;

	BACKGROUND_BITMAP_INIT;

	uint8_t mapData;
	uint8_t pixelData = 0;

	int outX;

	if (!objwinSlowPath) {
		if (!(flags & FLAG_TARGET_2)) {
			DRAW_BACKGROUND_MODE_2(NoBlend, NO_OBJWIN);
		} else {
			DRAW_BACKGROUND_MODE_2(Blend, NO_OBJWIN);
		}
	} else {
		if (!(flags & FLAG_TARGET_2)) {
			DRAW_BACKGROUND_MODE_2(NoBlend, OBJWIN);
		} else {
			DRAW_BACKGROUND_MODE_2(Blend, OBJWIN);
		}
	}
}

void GBAVideoSoftwareRendererDrawBackgroundMode3(struct GBAVideoSoftwareRenderer* renderer, struct GBAVideoSoftwareBackground* background, int inY) {
	BACKGROUND_BITMAP_INIT;

	uint32_t color = renderer->normalPalette[0];

	int outX;
	for (outX = renderer->start; outX < renderer->end; ++outX) {
		BACKGROUND_BITMAP_ITERATE(renderer->masterEnd, GBA_VIDEO_VERTICAL_PIXELS);

		if (!mosaicWait) {
			LOAD_16(color, ((localX >> 8) + (localY >> 8) * renderer->masterEnd) << 1, renderer->d.vramBG[0]);
			color = mColorFrom555(color);
			mosaicWait = mosaicH;
		} else {
			--mosaicWait;
		}

		uint32_t current = renderer->row[outX];
		if (!objwinSlowPath || (!(current & FLAG_OBJWIN)) != objwinOnly) {
			unsigned mergedFlags = flags;
			if (current & FLAG_OBJWIN) {
				mergedFlags = objwinFlags;
			}
			if (!variant) {
				_compositeBlendObjwin(renderer, outX, color | mergedFlags, current);
			} else if (renderer->blendEffect == BLEND_BRIGHTEN) {
				_compositeBlendObjwin(renderer, outX, _brighten(color, renderer->bldy) | mergedFlags, current);
			} else if (renderer->blendEffect == BLEND_DARKEN) {
				_compositeBlendObjwin(renderer, outX, _darken(color, renderer->bldy) | mergedFlags, current);
			}
		}
	}
}

void GBAVideoSoftwareRendererDrawBackgroundMode4(struct GBAVideoSoftwareRenderer* renderer, struct GBAVideoSoftwareBackground* background, int inY) {
	BACKGROUND_BITMAP_INIT;

	uint16_t color = 0;
	uint32_t offset = 0;
	if (GBARegisterDISPCNTIsFrameSelect(renderer->dispcnt)) {
		offset = 0xA000;
	}

	int outX;
	for (outX = renderer->start; outX < renderer->end; ++outX) {
		BACKGROUND_BITMAP_ITERATE(renderer->masterEnd, GBA_VIDEO_VERTICAL_PIXELS);

		if (!mosaicWait) {
			color = ((uint8_t*)renderer->d.vramBG[0])[offset + (localX >> 8) + (localY >> 8) * renderer->masterEnd];

			mosaicWait = mosaicH;
		} else {
			--mosaicWait;
		}

		uint32_t current = renderer->row[outX];
		if (color && IS_WRITABLE(current)) {
			if (!objwinSlowPath) {
				_compositeBlendNoObjwin(renderer, outX, palette[color] | flags, current);
			} else if (objwinForceEnable || (!(current & FLAG_OBJWIN)) == objwinOnly) {
				color_t* currentPalette = (current & FLAG_OBJWIN) ? objwinPalette : palette;
				unsigned mergedFlags = flags;
				if (current & FLAG_OBJWIN) {
					mergedFlags = objwinFlags;
				}
				_compositeBlendObjwin(renderer, outX, currentPalette[color] | mergedFlags, current);
			}
		}
	}
}

void GBAVideoSoftwareRendererDrawBackgroundMode5(struct GBAVideoSoftwareRenderer* renderer, struct GBAVideoSoftwareBackground* background, int inY) {
	BACKGROUND_BITMAP_INIT;

	uint32_t color = renderer->normalPalette[0];
	uint32_t offset = 0;
	if (GBARegisterDISPCNTIsFrameSelect(renderer->dispcnt)) {
		offset = 0xA000;
	}

	int outX;
	for (outX = renderer->start; outX < renderer->end; ++outX) {
		BACKGROUND_BITMAP_ITERATE(160, 128);

		if (!mosaicWait) {
			LOAD_16(color, offset + (localX >> 8) * 2 + (localY >> 8) * 320, renderer->d.vramBG[0]);
			color = mColorFrom555(color);
			mosaicWait = mosaicH;
		} else {
			--mosaicWait;
		}

		uint32_t current = renderer->row[outX];
		if (!objwinSlowPath || (!(current & FLAG_OBJWIN)) != objwinOnly) {
			unsigned mergedFlags = flags;
			if (current & FLAG_OBJWIN) {
				mergedFlags = objwinFlags;
			}
			if (!variant) {
				_compositeBlendObjwin(renderer, outX, color | mergedFlags, current);
			} else if (renderer->blendEffect == BLEND_BRIGHTEN) {
				_compositeBlendObjwin(renderer, outX, _brighten(color, renderer->bldy) | mergedFlags, current);
			} else if (renderer->blendEffect == BLEND_DARKEN) {
				_compositeBlendObjwin(renderer, outX, _darken(color, renderer->bldy) | mergedFlags, current);
			}
		}
	}
}