mirror of
https://github.com/libretro/Genesis-Plus-GX.git
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75ac3317ed
(better not make VDP core hackish)
266 lines
10 KiB
C
266 lines
10 KiB
C
/***************************************************************************************
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* Genesis Plus
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* Sega Light Phaser, Menacer & Konami Justifiers support
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*
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* Copyright (C) 2007-2013 Eke-Eke (Genesis Plus GX)
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*
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* Redistribution and use of this code or any derivative works are permitted
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* provided that the following conditions are met:
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*
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* - Redistributions may not be sold, nor may they be used in a commercial
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* product or activity.
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*
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* - Redistributions that are modified from the original source must include the
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* complete source code, including the source code for all components used by a
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* binary built from the modified sources. However, as a special exception, the
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* source code distributed need not include anything that is normally distributed
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* (in either source or binary form) with the major components (compiler, kernel,
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* and so on) of the operating system on which the executable runs, unless that
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* component itself accompanies the executable.
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*
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* - Redistributions must reproduce the above copyright notice, this list of
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* conditions and the following disclaimer in the documentation and/or other
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* materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************************/
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#include "shared.h"
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/************************************************************************************/
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/* */
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/* H-counter values returned in H40 & H32 modes */
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/* */
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/* Inside VDP, dot counter register is 9-bit, with only upper 8 bits being returned */
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/* */
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/* The number of dots per raster line is 342 in H32 mode and 420 in H40 mode */
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/* */
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/************************************************************************************/
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static const uint8 hc_256[171] =
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{
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
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0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
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0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
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0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
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0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
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0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
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0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
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0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
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0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
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0x90, 0x91, 0x92, 0x93,
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0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
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0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF
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};
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static const uint8 hc_320[210] =
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{
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
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0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
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0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
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0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
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0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
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0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
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0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
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0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
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0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
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0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F,
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0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
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0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6,
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0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED,
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0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD,
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0xFE, 0xFF
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};
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static struct
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{
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uint8 State;
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uint8 Port;
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} lightgun;
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void lightgun_reset(int port)
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{
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input.analog[port][0] = bitmap.viewport.w / 2;
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input.analog[port][1] = bitmap.viewport.h / 2;
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lightgun.State = 0x40;
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lightgun.Port = 4;
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}
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void lightgun_refresh(int port)
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{
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/* Check that lightgun is enabled */
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if (port == lightgun.Port)
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{
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/* screen Y position */
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int y = input.analog[port][1] + input.y_offset;
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/* check if active line falls within current gun Y position */
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if ((y == v_counter) && (y < bitmap.viewport.h))
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{
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/* HL enabled ? */
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if (io_reg[5] & 0x80)
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{
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/* screen X position */
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int x = input.analog[port][0];
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/* Sega Menacer specific */
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if (input.system[1] == SYSTEM_MENACER)
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{
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/* raw position is scaled up by games */
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if (system_hw == SYSTEM_MCD)
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{
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x = (x * 304) / 320;
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}
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else
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{
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x = (x * 289) / 320;
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}
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}
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/* External Interrupt enabled ? */
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if (reg[11] & 0x08)
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{
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m68k_update_irq(2);
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}
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/* HVC latch enabled ? */
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if (reg[0] & 0x02)
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{
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/* line accurate V-Counter value */
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hvc_latch = 0x10000 | (y << 8);
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}
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else
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{
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/* HACK: force HVC latch even when disabled (a few games does not lock HV Counter but instead applies larger offset value) */
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hvc_latch = 0x20000 | (y << 8);
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}
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/* pixel accurate H-Counter value */
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if (reg[12] & 1)
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{
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hvc_latch |= hc_320[((x / 2) + input.x_offset) % 210];
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}
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else
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{
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hvc_latch |= hc_256[((x / 2) + input.x_offset) % 171];
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}
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}
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}
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else if (hvc_latch & 0x20000)
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{
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/* HVC should be free-running on other lines when latch is disabled (fixes "Gunfight - 3 in 1" randomization) */
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hvc_latch = 0;
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}
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}
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}
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/*--------------------------------------------------------------------------*/
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/* Sega Phaser */
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/*--------------------------------------------------------------------------*/
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INLINE unsigned char phaser_read(int port)
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{
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/* TL returns TRIGGER (INPUT_A) button status (active low) */
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unsigned char temp = ~((input.pad[port] >> 2) & 0x10);
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/* Check that TH is set as an input */
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if (io_reg[0x0F] & (0x02 << (port >> 1)))
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{
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/* Get current X position (phaser is only used in MS compatiblity mode) */
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int hcounter = hctab[(Z80.cycles + SMS_CYCLE_OFFSET) % MCYCLES_PER_LINE];
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/* Compare with gun position */
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int dx = input.analog[port][0] - (hcounter << 1);
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int dy = input.analog[port][1] - (v_counter);
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/* Check if current pixel is within lightgun spot ? */
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if ((abs(dy) <= 5) && (abs(dx) <= 60))
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{
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/* set TH low */
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temp &= ~0x40;
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/* prevents multiple latch at each port read */
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if (lightgun.State)
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{
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/* latch estimated HC value */
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hvc_latch = 0x10000 | (input.x_offset + (input.analog[port][0] >> 1));
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lightgun.State = 0;
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}
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else
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{
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lightgun.State = 1;
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}
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}
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}
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return temp & 0x7F;
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}
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unsigned char phaser_1_read(void)
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{
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return phaser_read(0);
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}
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unsigned char phaser_2_read(void)
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{
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return phaser_read(4);
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}
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/*--------------------------------------------------------------------------*/
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/* Sega Menacer */
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/*--------------------------------------------------------------------------*/
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unsigned char menacer_read(void)
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{
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/* D0=??? (INPUT_B), D1=TRIGGER (INPUT_A), D2=??? (INPUT_C), D3= START (INPUT_START) (active high) */
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/* TL & TR pins always return 0 (normally set as output) */
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/* TH always return 1 (0 on active pixel but button acquisition is always done during VBLANK) */
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unsigned data = input.pad[4] >> 4;
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return ((data & 0x09) | ((data >> 1) & 0x02) | ((data << 1) & 0x04) | 0x40);
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}
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/*--------------------------------------------------------------------------*/
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/* Konami Justifiers */
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/*--------------------------------------------------------------------------*/
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unsigned char justifier_read(void)
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{
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/* Gun detection */
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if (lightgun.State & 0x40)
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{
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return 0x30;
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}
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/* Return TRIGGER (INPUT_A) & START (INPUT_START) button status in D0-D1 (active low) */
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/* TL & TR pins should always return 1 (normally set as output) */
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/* LEFT & RIGHT pins should always return 0 */
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return (((~input.pad[lightgun.Port] >> 6) & 0x03) | 0x70);
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}
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void justifier_write(unsigned char data, unsigned char mask)
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{
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/* update bits set as output only, other bits are cleared (fixes Lethal Enforcers 2) */
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data &= mask;
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/* gun index */
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lightgun.Port = 4 + ((data >> 5) & 1);
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/* update internal state */
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lightgun.State = data;
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}
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