Chris Taylor
Ray casting engine implemented on the mBuino platform using the ST7735 LCD controller.
Ray casting engine written to test performance of the LCD_ST7735 library I wrote as a learning exercise on the mbed platform.
Revision 0:303768292f44, committed 2014-09-21
- Comitter:
- taylorza
- Date:
- Sun Sep 21 22:04:22 2014 +0000
- Child:
- 1:fdbc2be25831
- Commit message:
- LCD_ST7735 Raycaster on mBuino mbed platform
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/LCD_ST7735.lib Sun Sep 21 22:04:22 2014 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/taylorza/code/LCD_ST7735/#88d22437119c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Raycaster.cpp Sun Sep 21 22:04:22 2014 +0000
@@ -0,0 +1,236 @@
+#include "mbed.h"
+#include "common.h"
+#include "LCD_ST7735.h"
+#include "Raycaster.h"
+
+Raycaster::Raycaster(int left, int top, int width, int height,
+ int viewerDistance, int viewerHeight,
+ const uint8_t *pMap, int mapWidth, int mapHeight,
+ const uint16_t *pPalette) :
+ _display(P0_15, // backlight
+ P0_10, // reset
+ P0_18, // ds
+ P0_21, // mosi
+ P0_22, // miso
+ P1_15, // clk
+ P0_19),// cs
+ _pMap(pMap),
+ _mapWidth(mapWidth),
+ _mapHeight(mapHeight),
+ _pPalette(pPalette),
+ _left(left),
+ _width(width),
+ _top(top),
+ _height(height)
+{
+ _display.setOrientation(LCD_ST7735::Rotate90, false);
+ _display.clearScreen();
+
+ _right = left + width;
+ _halfWidth = width >> 1;
+ _horizCenter = left + _halfWidth;
+
+ _bottom = top + height;
+ _halfHeight = height >> 1;
+ _vertCenter = top + _halfHeight;
+
+ _viewerDistance = viewerDistance;
+ _viewerHeight = viewerHeight;
+
+ _viewVolume = 60 * PI / 180;
+ _halfViewVolume = _viewVolume / 2;
+
+ _ainc = _viewVolume / _width;
+
+ _viewDistanceTimesHeight = _viewerDistance * _viewerHeight;
+ _heightRatio = (_viewerDistance << CELL_SIZE_SHIFT);
+ _pSlivers = new Sliver[_width >> 1];
+}
+
+void Raycaster::setCellPosition(int x, int y)
+{
+ _playerX = x << CELL_SIZE_SHIFT;
+ _playerY = y << CELL_SIZE_SHIFT;
+ _playerViewAngle = 0;
+}
+
+void Raycaster::rotate(float radians)
+{
+ _playerViewAngle += radians;
+ if (_playerViewAngle > PI2) _playerViewAngle -= PI2;
+ if (_playerViewAngle < 0) _playerViewAngle += PI2;
+}
+
+void Raycaster::move(int distance)
+{
+ int mx;
+ int my;
+
+ // Calculate the change in x and y coordinates
+ float dx = sin(_playerViewAngle) * distance;
+ float dy = cos(_playerViewAngle) * -distance;
+
+ // Check for collisions with walls
+ float nx = _playerX + (dx * 4);
+ float ny = _playerY + (dy * 4);
+
+ // Check for wall in the x direction and move if open
+ mx = ((int)nx) >> CELL_SIZE_SHIFT;
+ my = ((int)_playerY) >> CELL_SIZE_SHIFT;
+ if (_pMap[mx + (my * _mapWidth)] == 0)
+ {
+ _playerX += dx;
+ }
+
+ // Check for wall in the y direction and move if open
+ mx = ((int)_playerX) >> CELL_SIZE_SHIFT;
+ my = ((int)ny) >> CELL_SIZE_SHIFT;
+ if (_pMap[mx + (my * _mapWidth)] == 0)
+ {
+ _playerY += dy;
+ }
+}
+
+void Raycaster::renderFrame()
+{
+ int xd, yd;
+ int grid_x, grid_y;
+ float xcross_x, xcross_y;
+ float ycross_x, ycross_y;
+ int xmaze, ymaze;
+ float distance;
+ int tmcolumn;
+ uint8_t cellValue;
+
+ int xview = FLOAT2INT(_playerX);
+ int yview = FLOAT2INT(_playerY);
+
+ float columnAngle = _halfViewVolume;
+ float ainc2 = _ainc * 2;
+ Sliver *pSliver = _pSlivers;
+ for (int column = 0; column < _width; column += 2, columnAngle -= ainc2, pSliver++)
+ {
+ float radians = _playerViewAngle - columnAngle;
+
+ int xdiff = FLOAT2INT(CELL_SIZE * sin(radians));
+ int ydiff = FLOAT2INT(-CELL_SIZE * cos(radians));
+
+ if (xdiff == 0) xdiff = 1;
+
+ float slope = (float)ydiff / xdiff;
+ if (slope == 0.0f) slope = 0.001f;
+
+ int x = xview;
+ int y = yview;
+
+ for(;;)
+ {
+ if (xdiff > 0)
+ {
+ grid_x = ((int)x & CELL_BIT_MASK) + CELL_SIZE;
+ }
+ else
+ {
+ grid_x = ((int)x & CELL_BIT_MASK) - 1;
+ }
+
+ if (ydiff > 0)
+ {
+ grid_y = ((int)y & CELL_BIT_MASK) + CELL_SIZE;
+ }
+ else
+ {
+ grid_y = ((int)y & CELL_BIT_MASK) - 1;
+ }
+
+ xcross_x = grid_x;
+ xcross_y = y + slope * (grid_x - x);
+
+ ycross_x = x + (grid_y - y) / slope;
+ ycross_y = grid_y;
+
+ xd = xcross_x - x;
+ yd = xcross_y - y;
+ int xdist = (xd * xd) + (yd * yd);
+
+ xd = ycross_x - x;
+ yd = ycross_y - y;
+ int ydist = (xd * xd) + (yd * yd);
+
+ if (xdist < ydist)
+ {
+ xmaze = (int)xcross_x >> CELL_SIZE_SHIFT;
+ ymaze = (int)xcross_y >> CELL_SIZE_SHIFT;
+
+ x = xcross_x;
+ y = xcross_y;
+
+ tmcolumn = (int)y & CELL_SIZE_MASK;
+ }
+ else
+ {
+ xmaze = (int)ycross_x >> CELL_SIZE_SHIFT;
+ ymaze = (int)ycross_y >> CELL_SIZE_SHIFT;
+
+ x = ycross_x;
+ y = ycross_y;
+
+ tmcolumn = (int)x & CELL_SIZE_MASK;
+ }
+
+ cellValue = _pMap[xmaze + (ymaze * _mapWidth)];
+ if (cellValue != 0) break;
+ }
+
+ xd = x - xview;
+ yd = y - yview;
+ distance = sqrt(((xd * xd) + (yd * yd)) * cos(columnAngle));
+ if (distance == 0) distance = 1;
+
+ int height = _heightRatio / distance;
+ if (height == 0) height = 1;
+
+ int bot = _viewDistanceTimesHeight / distance + _vertCenter;
+ int top = bot - height;
+
+ int t = tmcolumn;
+ int dheight = height;
+ int iheight = CELL_SIZE;
+ float yratio = (float)CELL_SIZE / height;
+
+ if (top < _top)
+ {
+ int clipBy = _top - top;
+ int clipRatio = (int)(clipBy * yratio);
+ dheight-= clipBy;
+ t += clipRatio << CELL_SIZE_SHIFT;
+ iheight -= clipRatio;
+ top = _top;
+ }
+
+ if (bot >= _bottom)
+ {
+ int clipBy = bot - _bottom;
+ dheight -= clipBy;
+ iheight -= (int)(clipBy * yratio);
+ bot = _bottom;
+ }
+
+ uint16_t color = 0xf800;
+
+ color = _pPalette[cellValue];
+
+ pSliver->top = top;
+ pSliver->bottom = bot;
+ pSliver->color = color;
+ }
+
+ int x = _left;
+ pSliver = _pSlivers;
+ for(int column = 0; column < _width; column += 2, x += 2, pSliver++)
+ {
+ _display.fillRect(x, _top, x + 1, pSliver->top, *_pPalette);
+ _display.fillRect(x, pSliver->top, x + 1, pSliver->bottom, pSliver->color);
+ _display.fillRect(x, pSliver->bottom, x + 1, _bottom, *_pPalette);
+ }
+}
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Raycaster.h Sun Sep 21 22:04:22 2014 +0000
@@ -0,0 +1,59 @@
+#ifndef __RATYCASTER_H__
+#define __RATYCASTER_H__
+class Raycaster
+{
+ public:
+ Raycaster(int left, int top, int width, int height,
+ int viewerDistance, int viewerHeight,
+ const uint8_t *pMap, int mapWidth, int mapHeight,
+ const uint16_t *pPalette);
+
+ void renderFrame();
+
+ void setCellPosition(int x, int y);
+ void rotate(float radians);
+ void move(int distance);
+
+ private:
+ struct Sliver
+ {
+ uint8_t top;
+ uint8_t bottom;
+ uint16_t color;
+ };
+ private:
+ LCD_ST7735 _display;
+
+ const uint8_t *_pMap;
+ int _mapWidth;
+ int _mapHeight;
+ const uint16_t *_pPalette;
+ int _viewDistanceTimesHeight;
+ Sliver *_pSlivers;
+
+ int _left;
+ int _right;
+ int _width;
+ int _halfWidth;
+ int _horizCenter;
+
+ int _top;
+ int _bottom;
+ int _height;
+ int _halfHeight;
+ int _vertCenter;
+
+ int _viewerDistance;
+ int _viewerHeight;
+ float _viewerDistanceHeightRatio;
+ float _viewVolume;
+ float _halfViewVolume;
+
+ float _ainc;
+ int _heightRatio;
+
+ float _playerX;
+ float _playerY;
+ float _playerViewAngle;
+};
+#endif //__RATYCASTER_H__
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/common.h Sun Sep 21 22:04:22 2014 +0000 @@ -0,0 +1,17 @@ +#ifndef __COMMON_H__ +#define __COMMON_H__ + +#ifndef PI +#define PI 3.14159265358979323846f +#endif + +#define PI2 6.28318530717958647692f + +#define CELL_SIZE 32 +#define CELL_SIZE_SHIFT 5 +#define CELL_SIZE_MASK 0x1f +#define CELL_BIT_MASK 0xffe0 + +#define FLOAT2INT(x) ((int)((x) + 0.5)) + +#endif //__COMMON_H__
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Sun Sep 21 22:04:22 2014 +0000
@@ -0,0 +1,59 @@
+#include "mbed.h"
+#include "common.h"
+#include "LCD_ST7735.h"
+#include "Color565.h"
+#include "Raycaster.h"
+
+static const uint8_t g_map[] =
+{
+ 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
+ 1,0,0,0,0,0,0,1,1,0,0,0,0,0,0,4,
+ 1,0,1,1,1,1,0,1,1,0,1,1,1,1,0,4,
+ 1,0,1,0,0,0,0,1,1,0,0,0,0,1,0,4,
+ 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,4,
+ 1,1,3,4,3,3,3,0,0,2,2,2,2,2,2,4,
+ 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,4,
+ 1,0,0,0,0,0,1,0,0,1,0,0,0,0,0,4,
+ 1,1,1,1,0,0,1,0,0,1,0,0,3,3,3,4,
+ 3,0,0,0,0,0,1,0,0,1,0,0,0,0,0,4,
+ 3,0,0,1,1,1,0,0,0,0,1,1,1,0,0,4,
+ 3,0,0,1,0,0,0,0,0,0,0,0,1,0,0,4,
+ 3,0,0,1,0,0,2,4,4,2,0,0,1,0,0,4,
+ 3,0,0,1,0,0,0,0,0,0,0,0,1,0,0,4,
+ 3,0,0,0,0,1,0,0,0,0,1,0,0,0,0,4,
+ 3,1,1,1,1,1,1,1,1,1,1,1,1,1,1,4,
+};
+
+static const uint16_t g_palette[] =
+{
+ Color565::Black,
+ Color565::Red,
+ Color565::Green,
+ Color565::Blue,
+ Color565::Yellow
+};
+
+AnalogIn stickX(P0_11);
+AnalogIn stickY(P0_13);
+
+main()
+{
+ Raycaster rayCaster(0, 10, 160, 108,
+ 96, CELL_SIZE / 2,
+ g_map, 16, 16,
+ g_palette);
+
+ rayCaster.setCellPosition(8, 8);
+
+ while (true)
+ {
+ rayCaster.renderFrame();
+
+ if (stickX < 0.3) rayCaster.rotate(-0.1);
+ else if (stickX > 0.7) rayCaster.rotate(0.1);;
+
+ if (stickY < 0.3) rayCaster.move(4);
+ else if (stickY > 0.7) rayCaster.move(-4);
+ }
+}
+
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Sun Sep 21 22:04:22 2014 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/552587b429a1 \ No newline at end of file