1 files changed, 240 insertions, 0 deletions
diff --git a/engines/zvision/graphics/render_table.cpp b/engines/zvision/graphics/render_table.cpp
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+++ b/engines/zvision/graphics/render_table.cpp
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+/* 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.
+*
+*/
+
+#include "common/scummsys.h"
+
+#include "zvision/graphics/render_table.h"
+
+#include "common/rect.h"
+
+#include "graphics/colormasks.h"
+
+
+namespace ZVision {
+
+RenderTable::RenderTable(uint numColumns, uint numRows)
+		: _numRows(numRows),
+		  _numColumns(numColumns),
+		  _renderState(FLAT) {
+	assert(numRows != 0 && numColumns != 0);
+
+	_internalBuffer = new Common::Point[numRows * numColumns];
+}
+
+RenderTable::~RenderTable() {
+	delete[] _internalBuffer;
+}
+
+void RenderTable::setRenderState(RenderState newState) {
+	_renderState = newState;
+
+	switch (newState) {
+	case PANORAMA:
+		_panoramaOptions.fieldOfView = 27.0f;
+		_panoramaOptions.linearScale = 0.55f;
+		_panoramaOptions.reverse = false;
+		break;
+	case TILT:
+		_tiltOptions.fieldOfView = 27.0f;
+		_tiltOptions.linearScale = 0.55f;
+		_tiltOptions.reverse = false;
+		break;
+	case FLAT:
+		// Intentionally left empty
+		break;
+	}
+}
+
+const Common::Point RenderTable::convertWarpedCoordToFlatCoord(const Common::Point &point) {
+	// If we're outside the range of the RenderTable, no warping is happening. Return the maximum image coords
+	if (point.x >= (int16)_numColumns || point.y >= (int16)_numRows || point.x < 0 || point.y < 0) {
+		int16 x = CLIP<int16>(point.x, 0, (int16)_numColumns);
+		int16 y = CLIP<int16>(point.y, 0, (int16)_numRows);
+		return Common::Point(x, y);
+	}
+
+	uint32 index = point.y * _numColumns + point.x;
+
+	Common::Point newPoint(point);
+	newPoint.x += _internalBuffer[index].x;
+	newPoint.y += _internalBuffer[index].y;
+
+	return newPoint;
+}
+
+uint16 mixTwoRGB(uint16 colorOne, uint16 colorTwo, float percentColorOne) {
+	assert(percentColorOne < 1.0f);
+
+	float rOne = float((colorOne & Graphics::ColorMasks<555>::kRedMask) >> Graphics::ColorMasks<555>::kRedShift);
+	float rTwo = float((colorTwo & Graphics::ColorMasks<555>::kRedMask) >> Graphics::ColorMasks<555>::kRedShift);
+	float gOne = float((colorOne & Graphics::ColorMasks<555>::kGreenMask) >> Graphics::ColorMasks<555>::kGreenShift);
+	float gTwo = float((colorTwo & Graphics::ColorMasks<555>::kGreenMask) >> Graphics::ColorMasks<555>::kGreenShift);
+	float bOne = float((colorOne & Graphics::ColorMasks<555>::kBlueMask) >> Graphics::ColorMasks<555>::kBlueShift);
+	float bTwo = float((colorTwo & Graphics::ColorMasks<555>::kBlueMask) >> Graphics::ColorMasks<555>::kBlueShift);
+
+	float rFinal = rOne * percentColorOne + rTwo * (1.0f - percentColorOne);
+	float gFinal = gOne * percentColorOne + gTwo * (1.0f - percentColorOne);
+	float bFinal = bOne * percentColorOne + bTwo * (1.0f - percentColorOne);
+
+	uint16 returnColor = (byte(rFinal + 0.5f) << Graphics::ColorMasks<555>::kRedShift) |
+	                     (byte(gFinal + 0.5f) << Graphics::ColorMasks<555>::kGreenShift) |
+						 (byte(bFinal + 0.5f) << Graphics::ColorMasks<555>::kBlueShift);
+
+	return returnColor;
+}
+
+void RenderTable::mutateImage(uint16 *sourceBuffer, uint16* destBuffer, uint32 destWidth, const Common::Rect &subRect) {
+	uint32 destOffset = 0;
+
+	for (int16 y = subRect.top; y < subRect.bottom; ++y) {
+		uint32 sourceOffset = y * _numColumns;
+
+		for (int16 x = subRect.left; x < subRect.right; ++x) {
+			uint32 normalizedX = x - subRect.left;
+			uint32 index = sourceOffset + x;
+
+			// RenderTable only stores offsets from the original coordinates
+			uint32 sourceYIndex = y + _internalBuffer[index].y;
+			uint32 sourceXIndex = x + _internalBuffer[index].x;
+			
+			destBuffer[destOffset + normalizedX] = sourceBuffer[sourceYIndex * _numColumns + sourceXIndex];
+		}
+
+		destOffset += destWidth;
+	}
+}
+
+void RenderTable::generateRenderTable() {
+	switch (_renderState) {
+	case ZVision::RenderTable::PANORAMA:
+		generatePanoramaLookupTable();
+		break;
+	case ZVision::RenderTable::TILT:
+		generateTiltLookupTable();
+		break;
+	case ZVision::RenderTable::FLAT:
+		// Intentionally left empty
+		break;
+	}
+}
+
+void RenderTable::generatePanoramaLookupTable() {
+	memset(_internalBuffer, 0, _numRows * _numColumns * sizeof(uint16));
+
+	float halfWidth = (float)_numColumns / 2.0f;
+	float halfHeight = (float)_numRows / 2.0f;
+
+	float fovInRadians = (_panoramaOptions.fieldOfView * M_PI / 180.0f);
+	float cylinderRadius = halfHeight / tan(fovInRadians);
+
+	for (uint x = 0; x < _numColumns; ++x) {
+		// Add an offset of 0.01 to overcome zero tan/atan issue (vertical line on half of screen)
+		// Alpha represents the horizontal angle between the viewer at the center of a cylinder and x
+		float alpha = atan(((float)x - halfWidth + 0.01f) / cylinderRadius);
+
+		// To get x in cylinder coordinates, we just need to calculate the arc length
+		// We also scale it by _panoramaOptions.linearScale
+		int32 xInCylinderCoords = int32(floor((cylinderRadius * _panoramaOptions.linearScale * alpha) + halfWidth));
+		
+		float cosAlpha = cos(alpha);
+
+		for (uint y = 0; y < _numRows; ++y) {
+			// To calculate y in cylinder coordinates, we can do similar triangles comparison, 
+			// comparing the triangle from the center to the screen and from the center to the edge of the cylinder
+			int32 yInCylinderCoords = int32(floor(halfHeight + ((float)y - halfHeight) * cosAlpha));
+
+			uint32 index = y * _numColumns + x;
+
+			// Only store the (x,y) offsets instead of the absolute positions
+			_internalBuffer[index].x = xInCylinderCoords - x;
+			_internalBuffer[index].y = yInCylinderCoords - y;
+		}
+	}
+}
+
+void RenderTable::generateTiltLookupTable() {
+	float halfWidth = (float)_numColumns / 2.0f;
+	float halfHeight = (float)_numRows / 2.0f;
+
+	float fovInRadians = (_tiltOptions.fieldOfView * M_PI / 180.0f);
+	float cylinderRadius = halfWidth / tan(fovInRadians);
+
+	for (uint y = 0; y < _numRows; ++y) {
+	
+		// Add an offset of 0.01 to overcome zero tan/atan issue (horizontal line on half of screen)
+		// Alpha represents the vertical angle between the viewer at the center of a cylinder and y
+		float alpha = atan(((float)y - halfHeight + 0.01f) / cylinderRadius);
+
+		// To get y in cylinder coordinates, we just need to calculate the arc length
+		// We also scale it by _tiltOptions.linearScale
+		int32 yInCylinderCoords = int32(floor((cylinderRadius * _tiltOptions.linearScale * alpha) + halfHeight));
+
+		float cosAlpha = cos(alpha);
+		uint32 columnIndex = y * _numColumns;
+
+		for (uint x = 0; x < _numColumns; ++x) {
+			// To calculate x in cylinder coordinates, we can do similar triangles comparison, 
+			// comparing the triangle from the center to the screen and from the center to the edge of the cylinder
+			int32 xInCylinderCoords = int32(floor(halfWidth + ((float)x - halfWidth) * cosAlpha));
+
+			uint32 index = columnIndex + x;
+
+			// Only store the (x,y) offsets instead of the absolute positions
+			_internalBuffer[index].x = xInCylinderCoords - x;
+			_internalBuffer[index].y = yInCylinderCoords - y;
+		}
+	}
+}
+
+void RenderTable::setPanoramaFoV(float fov) {
+	assert(fov > 0.0f);
+
+	_panoramaOptions.fieldOfView = fov;
+}
+
+void RenderTable::setPanoramaScale(float scale) {
+	assert(scale > 0.0f);
+
+	_panoramaOptions.linearScale = scale;
+}
+
+void RenderTable::setPanoramaReverse(bool reverse) {
+	_panoramaOptions.reverse = reverse;
+}
+
+void RenderTable::setTiltFoV(float fov) {
+	assert(fov > 0.0f);
+
+	_tiltOptions.fieldOfView = fov;
+}
+
+void RenderTable::setTiltScale(float scale) {
+	assert(scale > 0.0f);
+
+	_tiltOptions.linearScale = scale;
+}
+
+void RenderTable::setTiltReverse(bool reverse) {
+	_tiltOptions.reverse = reverse;
+}
+
+} // End of namespace ZVision