C++ MultiScreenHeader类代码示例

byte *Sword2Engine::fetchForegroundParallaxLayer(byte *screenFile, int layer) {
	if (isPsx()) {
		byte *psxParallax = _screen->getPsxScrCache(2);

		// Manage cache for psx parallaxes
		if (!_screen->getPsxScrCacheStatus(2)) { // This parallax layer is not present
			return NULL;
		} else if (psxParallax) { // Parallax layer present and cached
			return psxParallax;
		} else { // Present, but still not cached
			uint32 locNo = _logic->getLocationNum();

			// We have a wrong location number at start, fix that
			locNo = (locNo == 0) ? 3 : locNo;

			psxParallax = fetchPsxParallax(locNo, 1);
			_screen->setPsxScrCache(psxParallax, 2);
			return psxParallax;
		}
	} else {
		MultiScreenHeader mscreenHeader;

		mscreenHeader.read(screenFile + ResHeader::size());
		assert(mscreenHeader.fg_parallax[layer]);
		return screenFile + ResHeader::size() + mscreenHeader.fg_parallax[layer];
	}
}

byte *Sword2Engine::fetchBackgroundLayer(byte *screenFile) {
	if (isPsx()) {
		byte *psxBackground = _screen->getPsxScrCache(1);

		// Manage cache for psx backgrounds
		if (psxBackground) { // Background is cached
			return psxBackground;
		} else { // Background not cached
			uint32 locNo = _logic->getLocationNum();

			// We have a wrong location number at start, fix that
			locNo = (locNo == 0) ? 3 : locNo;

			psxBackground = fetchPsxBackground(locNo);
			_screen->setPsxScrCache(psxBackground, 1);
			return psxBackground;
		}
	} else {
		MultiScreenHeader mscreenHeader;

		mscreenHeader.read(screenFile + ResHeader::size());
		assert(mscreenHeader.screen);
		return screenFile + ResHeader::size() + mscreenHeader.screen + ScreenHeader::size();
	}
}

void Sword2Engine::fetchPalette(byte *screenFile, byte *palBuffer) {
	byte *palette;

	if (isPsx()) { // PSX version doesn't have a "MultiScreenHeader", instead there's a ScreenHeader and a tag
		palette = screenFile + ResHeader::size() + ScreenHeader::size() + 2;
	} else {
		MultiScreenHeader mscreenHeader;

		mscreenHeader.read(screenFile + ResHeader::size());
		palette = screenFile + ResHeader::size() + mscreenHeader.palette;
	}

	// Always set color 0 to black, because while most background screen
	// palettes have a bright color 0 it should come out as black in the
	// game.

	palBuffer[0] = 0;
	palBuffer[1] = 0;
	palBuffer[2] = 0;

	for (uint i = 4, j = 3; i < 4 * 256; i += 4, j += 3) {
		palBuffer[j + 0] = palette[i + 0];
		palBuffer[j + 1] = palette[i + 1];
		palBuffer[j + 2] = palette[i + 2];
	}
}

byte *Sword2Engine::fetchShadingMask(byte *screenFile) {
	if (isPsx()) return NULL;

	MultiScreenHeader mscreenHeader;

	mscreenHeader.read(screenFile + ResHeader::size());

	return screenFile + ResHeader::size() + mscreenHeader.maskOffset;
}

byte *Sword2Engine::fetchLayerHeader(byte *screenFile, uint16 layerNo) {
#ifdef SWORD2_DEBUG
	ScreenHeader screenHead;

	screenHead.read(fetchScreenHeader(screenFile));
	assert(layerNo < screenHead.noLayers);
#endif

	if (isPsx()) {
		return screenFile + ResHeader::size() + ScreenHeader::size() + 2 + 0x400 + layerNo * LayerHeader::size();
	} else {
		MultiScreenHeader mscreenHeader;

		mscreenHeader.read(screenFile + ResHeader::size());
		return screenFile + ResHeader::size() + mscreenHeader.layers + layerNo * LayerHeader::size();
	}
}

void Screen::buildDisplay() {
	if (_thisScreen.new_palette) {
		// start the layer palette fading up
		startNewPalette();

		// should be reset to zero at start of each screen change
		_largestLayerArea = 0;
		_largestSpriteArea = 0;
	}

	// Does this ever happen?
	if (!_thisScreen.background_layer_id)
		return;

	// there is a valid screen to run

	setScrollTarget(_thisScreen.scroll_offset_x, _thisScreen.scroll_offset_y);
	_vm->_mouse->animateMouse();
	startRenderCycle();

	byte *file = _vm->_resman->openResource(_thisScreen.background_layer_id);

	MultiScreenHeader screenLayerTable;
	memset(&screenLayerTable, 0, sizeof(screenLayerTable));

	if (!Sword2Engine::isPsx()) // On PSX version, there would be nothing to read here
		screenLayerTable.read(file + ResHeader::size());

	// Render at least one frame, but if the screen is scrolling, and if
	// there is time left, we will render extra frames to smooth out the
	// scrolling.

	do {
		// first background parallax + related anims
		if (Sword2Engine::isPsx() || screenLayerTable.bg_parallax[0]) { // No need to check on PSX version
			renderParallax(_vm->fetchBackgroundParallaxLayer(file, 0), 0);
			drawBackPar0Frames();
		}

		// second background parallax + related anims
		if (!Sword2Engine::isPsx() && screenLayerTable.bg_parallax[1]) { // Nothing here in PSX version
			renderParallax(_vm->fetchBackgroundParallaxLayer(file, 1), 1);
			drawBackPar1Frames();
		}

		// normal backround layer (just the one!)
		renderParallax(_vm->fetchBackgroundLayer(file), 2);

		// sprites & layers
		drawBackFrames();	// background sprites
		drawSortFrames(file);	// sorted sprites & layers
		drawForeFrames();	// foreground sprites

		// first foreground parallax + related anims

		if (Sword2Engine::isPsx() || screenLayerTable.fg_parallax[0]) {
			renderParallax(_vm->fetchForegroundParallaxLayer(file, 0), 3);
			drawForePar0Frames();
		}

		// second foreground parallax + related anims

		if (!Sword2Engine::isPsx() && screenLayerTable.fg_parallax[1]) {
			renderParallax(_vm->fetchForegroundParallaxLayer(file, 1), 4);
			drawForePar1Frames();
		}

		_vm->_debugger->drawDebugGraphics();
		_vm->_fontRenderer->printTextBlocs();
		_vm->_mouse->processMenu();

		updateDisplay();

		_frameCount++;
		if (getTick() > _cycleTime) {
			_fps = _frameCount;
			_frameCount = 0;
			_cycleTime = getTick() + 1000;
		}
	} while (!endRenderCycle());

	_vm->_resman->closeResource(_thisScreen.background_layer_id);

}