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Diffstat (limited to 'src/devices/bus/a2gameio/brightpen.cpp')
-rw-r--r-- | src/devices/bus/a2gameio/brightpen.cpp | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/devices/bus/a2gameio/brightpen.cpp b/src/devices/bus/a2gameio/brightpen.cpp new file mode 100644 index 00000000000..41d8ce3b512 --- /dev/null +++ b/src/devices/bus/a2gameio/brightpen.cpp @@ -0,0 +1,140 @@ +// license:BSD-3-Clause +// copyright-holders:kmg +/********************************************************************* + + Apple II Softape Bright Pen interface for the Apple ][/][+ + +*********************************************************************/ + +#include "emu.h" +#include "bus/a2gameio/brightpen.h" +#include "screen.h" + + +namespace { + +#define BRIGHTPEN_POINT "BRIGHTPEN_POINT" +#define BRIGHTPEN_X "BRIGHTPEN_X" +#define BRIGHTPEN_Y "BRIGHTPEN_Y" + +// ======================> apple2_brightpen_device + +class apple2_brightpen_device : public device_t, public device_a2gameio_interface +{ +public: + // construction/destruction + apple2_brightpen_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) + : device_t(mconfig, APPLE2_BRIGHTPEN, tag, owner, clock) + , device_a2gameio_interface(mconfig, *this) + , m_brightpen_point(*this, BRIGHTPEN_POINT) + , m_brightpen_x(*this, BRIGHTPEN_X) + , m_brightpen_y(*this, BRIGHTPEN_Y) + { + } + +protected: + // device_t implementation + virtual ioport_constructor device_input_ports() const override ATTR_COLD; + virtual void device_start() override ATTR_COLD; + + // device_a2gameio_interface implementation + virtual int sw0_r() override; + +private: + // input ports + required_ioport m_brightpen_point; + required_ioport m_brightpen_x; + required_ioport m_brightpen_y; + + // radius of circle picked up by the bright pen + static constexpr int PEN_X_RADIUS = 2; + static constexpr int PEN_Y_RADIUS = 1; + // brightness threshold + static constexpr int BRIGHTNESS_THRESHOLD = 0x20; + // # of CRT scanlines that sustain brightness + static constexpr int SUSTAIN = 22; +}; + +//************************************************************************** +// INPUT PORTS +//************************************************************************** + +static INPUT_PORTS_START( apple2_brightpen ) + PORT_START(BRIGHTPEN_X) + PORT_BIT( 0x3ff, 0x80, IPT_LIGHTGUN_X ) PORT_CROSSHAIR(X, 1.0, 0.0, 0) PORT_SENSITIVITY(45) PORT_KEYDELTA(15) PORT_MINMAX(0, 559) PORT_NAME("Bright Pen X") + PORT_START(BRIGHTPEN_Y) + PORT_BIT( 0x3ff, 0x80, IPT_LIGHTGUN_Y ) PORT_CROSSHAIR(Y, 1.0, 0.0, 0) PORT_SENSITIVITY(45) PORT_KEYDELTA(15) PORT_MINMAX(0, 191) PORT_NAME("Bright Pen Y") + PORT_START(BRIGHTPEN_POINT) + PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_NAME("Bright Pen pointed at screen") + PORT_BIT( 0xfe, IP_ACTIVE_LOW, IPT_UNUSED ) +INPUT_PORTS_END + +ioport_constructor apple2_brightpen_device::device_input_ports() const +{ + return INPUT_PORTS_NAME(apple2_brightpen); +} + +void apple2_brightpen_device::device_start() +{ +} + +// light detection logic based on zapper_sensor.cpp nes_zapper_sensor_device::detect_light + +int apple2_brightpen_device::sw0_r() +{ + if (!BIT(m_brightpen_point->read(), 0)) return 0; + + int pen_x_pos = m_brightpen_x->read(); + int pen_y_pos = m_brightpen_y->read(); + int beam_vpos = m_screen->vpos(); + int beam_hpos = m_screen->hpos(); + + // update the screen if the beam position is within the radius of the pen + if (!machine().side_effects_disabled()) + { + if (!m_screen->vblank()) + { + if (beam_vpos > pen_y_pos - PEN_Y_RADIUS || (beam_vpos == pen_y_pos - PEN_Y_RADIUS && beam_hpos >= pen_x_pos - PEN_X_RADIUS)) + { + m_screen->update_now(); + } + } + } + + int brightness_sum = 0; + int pixels_scanned = 0; + + // sum brightness of pixels nearby the pen position + for (int i = pen_x_pos - PEN_X_RADIUS; i <= pen_x_pos + PEN_X_RADIUS; i++) + { + for (int j = pen_y_pos - PEN_Y_RADIUS; j <= pen_y_pos + PEN_Y_RADIUS; j++) + { + // look at pixels within circular sensor + if ((pen_x_pos - i) * (pen_x_pos - i) + (pen_y_pos - j) * (pen_y_pos - j) <= PEN_X_RADIUS * PEN_Y_RADIUS) + { + rgb_t pix = m_screen->pixel(i, j); + + // only detect light if pen position is near, and behind, + // where the video generator is drawing on the CRT, + if (j <= beam_vpos && j > beam_vpos - SUSTAIN && (j != beam_vpos || i <= beam_hpos)) + { + brightness_sum += pix.r() + pix.g() + pix.b(); + } + pixels_scanned++; + } + } + } + + // light detected if average brightness is above threshold + return brightness_sum >= BRIGHTNESS_THRESHOLD * pixels_scanned; +} + +} // anonymous namespace + + +//************************************************************************** +// GLOBAL VARIABLES +//************************************************************************** + +// device type definition +DEFINE_DEVICE_TYPE_PRIVATE(APPLE2_BRIGHTPEN, device_a2gameio_interface, apple2_brightpen_device, "a2brightpen", "Softape Bright Pen") |