ZVISION: Create a class for handling all render table logic

Aka, creating the lookup tables, storing the current render state, and eventually doing
the image mutations.

2 files changed, 164 insertions, 0 deletions

diff --git a/engines/zvision/render_table.cpp b/engines/zvision/render_table.cpp
new file mode 100644
index 0000000000..1baf9514a3
--- /dev/null
+++ b/engines/zvision/render_table.cpp
@@ -0,0 +1,95 @@
+/* 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/render_table.h"
+
+
+namespace ZVision {
+
+RenderTable::RenderTable(uint32 numRows, uint32 numColumns)
+		: _numRows(numRows),
+		  _numColumns(numColumns) {
+	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 = 60;
+		_panoramaOptions.linearScale = 1;
+		generatePanoramaLookupTable();
+		break;
+	case TILT:
+		generateTiltLookupTable();
+		break;
+	case FLAT:
+		// Intentionally left empty
+		break;
+	}
+}
+
+void RenderTable::generatePanoramaLookupTable() {
+	float fieldOfView = _panoramaOptions.fieldOfView;
+	float scale = _panoramaOptions.linearScale;
+
+	memset(_internalBuffer, 0, _numRows * _numColumns * sizeof(uint16));
+
+	float halfWidth = (float)_numColumns / 2.0f;
+	float halfHeight = (float)_numRows / 2.0f;
+
+	float fovRadians = (fieldOfView * M_PI / 180.0f);
+	float halfHeightOverTan = halfHeight / tan(fovRadians);
+	float tanOverHalfHeight = tan(fovRadians) / halfHeight;
+
+	for (uint32 x = 0; x < _numRows; x++) {
+		// Add an offset of 0.01 to overcome zero tan/atan issue (vertical line on half of screen)
+		float xPos = (float)x - halfWidth + 0.01;
+		float tempX = atan(xPos*tanOverHalfHeight);
+
+		int32 newX = floor(scale * halfHeightOverTan * tempX);// + half_w);
+		float cosX = cos(tempX);
+
+		for (uint32 y = 0; y < _numColumns; y++) {
+			int32 newY = floor(halfHeight + (y - halfHeight) * cosX);
+
+			uint32 index = x * _numColumns + y;
+			_internalBuffer[index].x = newX; //pixel index
+			_internalBuffer[index].y = newY; //pixel index
+		}
+	}
+}
+
+void RenderTable::generateTiltLookupTable() {
+
+}
+
+} // End of namespace ZVision
diff --git a/engines/zvision/render_table.h b/engines/zvision/render_table.h
new file mode 100644
index 0000000000..9d54551c3b
--- /dev/null
+++ b/engines/zvision/render_table.h
@@ -0,0 +1,69 @@
+/* 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.
+ *
+ */
+
+#ifndef ZVISION_RENDER_TABLE_H
+#define ZVISION_RENDER_TABLE_H
+
+#include "common/types.h"
+#include "common/rect.h"
+
+namespace ZVision {
+
+class RenderTable {
+public:
+	RenderTable(uint32 numRows, uint32 numColumns);
+	~RenderTable();
+
+public:
+	enum RenderState {
+		PANORAMA,
+		TILT,
+		FLAT
+	};
+
+private:
+	uint32 _numColumns, _numRows;
+	Common::Point *_internalBuffer;
+	RenderState _renderState;
+
+	struct {
+		uint16 fieldOfView;
+		uint16 linearScale;
+	} _panoramaOptions;
+
+	// TODO: See if tilt and panorama need to have separate options
+	struct {
+		uint16 fieldOfView;
+		uint16 linearScale;
+	} _tiltOptions;
+
+public:
+	void setRenderState(RenderState newState);
+
+private:
+	void generatePanoramaLookupTable();
+	void generateTiltLookupTable();
+};
+
+} // End of namesapce ZVision
+
+#endif