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engines/icb/gfx/gfxstub.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.
+ *
+ * Additional copyright for this file:
+ * Copyright (C) 1999-2000 Revolution Software Ltd.
+ * This code is based on source code created by Revolution Software,
+ * used with permission.
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "engines/icb/gfx/gfxstub.h"
+#include "engines/icb/gfx/psx_scrn.h"
+
+namespace ICB {
+
+int32 _selFace;
+
+// Number of GPU packets to reserve
+#define PACKETMAX 2900 * 4
+// the size of a POLY_GT3 packet
+#define PACKETSIZE sizeof(POLY_GT3)
+// a full-up DR_LOAD is 17 int32s (68 bytes) and is the biggest type of packet
+#define PACKET_MAX_SIZE sizeof(DR_LOAD)
+#define PACKETMEM (PACKETMAX * PACKETSIZE)
+
+// Global place to create GPU packets
+// Use a ring system, so when get to end just start again from the beginning
+GPUPACKET packets[PACKETMEM]; /* GPU PACKETS AREA */
+GPUPACKET *drawpacket;
+GPUPACKET *drawpacketStart;
+GPUPACKET *drawpacketEnd;
+
+// Global double buffer index
+int32 drawBuf = 0;
+
+// Global ot arrays and stuff
+OT_tag *otarray[2];
+OT_tag *drawot;
+OT_tag otlist[2][OT_SIZE];
+
+// The min & max places to put Z data into the OT list
+int32 minZOTpos = 5;
+int32 maxZOTpos = OT_SIZE - 5;
+int32 nearClip = 0;
+int32 minUsedZpos = 20000;
+int32 maxUsedZpos = 0;
+
+int32 g_otz_shift = 0; // 1cm accuracy
+int32 g_otz_offset;
+
+// The zones for otz_shift computation
+#define OTZ_ZONE1 32000  // 1cm
+#define OTZ_ZONE2 64000  // 2cm
+#define OTZ_ZONE4 128000 // 4cm
+#define OTZ_ZONE8 256000 // 8cm
+
+void InitDrawing(void) {
+	// sort out the GPU packet memory
+	drawpacketStart = packets;
+	drawpacketEnd = packets + PACKETMEM - PACKET_MAX_SIZE * 2;
+	drawpacket = drawpacketStart;
+
+	otarray[0] = &(otlist[0][0]);
+	otarray[1] = &(otlist[1][0]);
+	drawBuf = 0;
+	drawot = otarray[drawBuf];
+
+	CLEAROTLIST(drawot, OT_SIZE);
+	minZOTpos = 5;
+	maxZOTpos = OT_SIZE - 5;
+	nearClip = 0;
+	minUsedZpos = 20000;
+	maxUsedZpos = 0;
+
+	g_otz_shift = 0; // 1cm accuracy
+	g_otz_offset = ((nearClip >> g_otz_shift) - minZOTpos);
+}
+
+void drawOTList(void) {
+	startDrawing();
+	DrawOTag(drawot + OT_FIRST);
+	endDrawing();
+	CLEAROTLIST(drawot, OT_SIZE);
+}
+
+void recoverFromOTcrash(void) {
+	endDrawing();
+	CLEAROTLIST(drawot, OT_SIZE);
+}
+
+void ResetZRange(void) {
+	// Reset the z-sorting values
+	nearClip = minUsedZpos - 100; // last used value -1m
+	int32 dz = maxUsedZpos - nearClip;
+	// Simple zones for otz_shift
+	if (dz < OTZ_ZONE1) // 1cm
+		g_otz_shift = 0;
+	else if (dz < OTZ_ZONE2) // 2cm
+		g_otz_shift = 1;
+	else if (dz < OTZ_ZONE4) // 4cm
+		g_otz_shift = 2;
+	else if (dz < OTZ_ZONE8) // 8cm
+		g_otz_shift = 3;
+	else
+		g_otz_shift = 4; // 16cm - yuck
+
+	g_otz_offset = ((nearClip >> g_otz_shift) - minZOTpos);
+
+	minUsedZpos = 20000;
+	maxUsedZpos = 0;
+}
+
+} // End of namespace ICB