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.
Raycaster.cpp@0:303768292f44, 2014-09-21 (annotated)
- Committer:
- taylorza
- Date:
- Sun Sep 21 22:04:22 2014 +0000
- Revision:
- 0:303768292f44
- Child:
- 1:fdbc2be25831
LCD_ST7735 Raycaster on mBuino mbed platform
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
taylorza | 0:303768292f44 | 1 | #include "mbed.h" |
taylorza | 0:303768292f44 | 2 | #include "common.h" |
taylorza | 0:303768292f44 | 3 | #include "LCD_ST7735.h" |
taylorza | 0:303768292f44 | 4 | #include "Raycaster.h" |
taylorza | 0:303768292f44 | 5 | |
taylorza | 0:303768292f44 | 6 | Raycaster::Raycaster(int left, int top, int width, int height, |
taylorza | 0:303768292f44 | 7 | int viewerDistance, int viewerHeight, |
taylorza | 0:303768292f44 | 8 | const uint8_t *pMap, int mapWidth, int mapHeight, |
taylorza | 0:303768292f44 | 9 | const uint16_t *pPalette) : |
taylorza | 0:303768292f44 | 10 | _display(P0_15, // backlight |
taylorza | 0:303768292f44 | 11 | P0_10, // reset |
taylorza | 0:303768292f44 | 12 | P0_18, // ds |
taylorza | 0:303768292f44 | 13 | P0_21, // mosi |
taylorza | 0:303768292f44 | 14 | P0_22, // miso |
taylorza | 0:303768292f44 | 15 | P1_15, // clk |
taylorza | 0:303768292f44 | 16 | P0_19),// cs |
taylorza | 0:303768292f44 | 17 | _pMap(pMap), |
taylorza | 0:303768292f44 | 18 | _mapWidth(mapWidth), |
taylorza | 0:303768292f44 | 19 | _mapHeight(mapHeight), |
taylorza | 0:303768292f44 | 20 | _pPalette(pPalette), |
taylorza | 0:303768292f44 | 21 | _left(left), |
taylorza | 0:303768292f44 | 22 | _width(width), |
taylorza | 0:303768292f44 | 23 | _top(top), |
taylorza | 0:303768292f44 | 24 | _height(height) |
taylorza | 0:303768292f44 | 25 | { |
taylorza | 0:303768292f44 | 26 | _display.setOrientation(LCD_ST7735::Rotate90, false); |
taylorza | 0:303768292f44 | 27 | _display.clearScreen(); |
taylorza | 0:303768292f44 | 28 | |
taylorza | 0:303768292f44 | 29 | _right = left + width; |
taylorza | 0:303768292f44 | 30 | _halfWidth = width >> 1; |
taylorza | 0:303768292f44 | 31 | _horizCenter = left + _halfWidth; |
taylorza | 0:303768292f44 | 32 | |
taylorza | 0:303768292f44 | 33 | _bottom = top + height; |
taylorza | 0:303768292f44 | 34 | _halfHeight = height >> 1; |
taylorza | 0:303768292f44 | 35 | _vertCenter = top + _halfHeight; |
taylorza | 0:303768292f44 | 36 | |
taylorza | 0:303768292f44 | 37 | _viewerDistance = viewerDistance; |
taylorza | 0:303768292f44 | 38 | _viewerHeight = viewerHeight; |
taylorza | 0:303768292f44 | 39 | |
taylorza | 0:303768292f44 | 40 | _viewVolume = 60 * PI / 180; |
taylorza | 0:303768292f44 | 41 | _halfViewVolume = _viewVolume / 2; |
taylorza | 0:303768292f44 | 42 | |
taylorza | 0:303768292f44 | 43 | _ainc = _viewVolume / _width; |
taylorza | 0:303768292f44 | 44 | |
taylorza | 0:303768292f44 | 45 | _viewDistanceTimesHeight = _viewerDistance * _viewerHeight; |
taylorza | 0:303768292f44 | 46 | _heightRatio = (_viewerDistance << CELL_SIZE_SHIFT); |
taylorza | 0:303768292f44 | 47 | _pSlivers = new Sliver[_width >> 1]; |
taylorza | 0:303768292f44 | 48 | } |
taylorza | 0:303768292f44 | 49 | |
taylorza | 0:303768292f44 | 50 | void Raycaster::setCellPosition(int x, int y) |
taylorza | 0:303768292f44 | 51 | { |
taylorza | 0:303768292f44 | 52 | _playerX = x << CELL_SIZE_SHIFT; |
taylorza | 0:303768292f44 | 53 | _playerY = y << CELL_SIZE_SHIFT; |
taylorza | 0:303768292f44 | 54 | _playerViewAngle = 0; |
taylorza | 0:303768292f44 | 55 | } |
taylorza | 0:303768292f44 | 56 | |
taylorza | 0:303768292f44 | 57 | void Raycaster::rotate(float radians) |
taylorza | 0:303768292f44 | 58 | { |
taylorza | 0:303768292f44 | 59 | _playerViewAngle += radians; |
taylorza | 0:303768292f44 | 60 | if (_playerViewAngle > PI2) _playerViewAngle -= PI2; |
taylorza | 0:303768292f44 | 61 | if (_playerViewAngle < 0) _playerViewAngle += PI2; |
taylorza | 0:303768292f44 | 62 | } |
taylorza | 0:303768292f44 | 63 | |
taylorza | 0:303768292f44 | 64 | void Raycaster::move(int distance) |
taylorza | 0:303768292f44 | 65 | { |
taylorza | 0:303768292f44 | 66 | int mx; |
taylorza | 0:303768292f44 | 67 | int my; |
taylorza | 0:303768292f44 | 68 | |
taylorza | 0:303768292f44 | 69 | // Calculate the change in x and y coordinates |
taylorza | 0:303768292f44 | 70 | float dx = sin(_playerViewAngle) * distance; |
taylorza | 0:303768292f44 | 71 | float dy = cos(_playerViewAngle) * -distance; |
taylorza | 0:303768292f44 | 72 | |
taylorza | 0:303768292f44 | 73 | // Check for collisions with walls |
taylorza | 0:303768292f44 | 74 | float nx = _playerX + (dx * 4); |
taylorza | 0:303768292f44 | 75 | float ny = _playerY + (dy * 4); |
taylorza | 0:303768292f44 | 76 | |
taylorza | 0:303768292f44 | 77 | // Check for wall in the x direction and move if open |
taylorza | 0:303768292f44 | 78 | mx = ((int)nx) >> CELL_SIZE_SHIFT; |
taylorza | 0:303768292f44 | 79 | my = ((int)_playerY) >> CELL_SIZE_SHIFT; |
taylorza | 0:303768292f44 | 80 | if (_pMap[mx + (my * _mapWidth)] == 0) |
taylorza | 0:303768292f44 | 81 | { |
taylorza | 0:303768292f44 | 82 | _playerX += dx; |
taylorza | 0:303768292f44 | 83 | } |
taylorza | 0:303768292f44 | 84 | |
taylorza | 0:303768292f44 | 85 | // Check for wall in the y direction and move if open |
taylorza | 0:303768292f44 | 86 | mx = ((int)_playerX) >> CELL_SIZE_SHIFT; |
taylorza | 0:303768292f44 | 87 | my = ((int)ny) >> CELL_SIZE_SHIFT; |
taylorza | 0:303768292f44 | 88 | if (_pMap[mx + (my * _mapWidth)] == 0) |
taylorza | 0:303768292f44 | 89 | { |
taylorza | 0:303768292f44 | 90 | _playerY += dy; |
taylorza | 0:303768292f44 | 91 | } |
taylorza | 0:303768292f44 | 92 | } |
taylorza | 0:303768292f44 | 93 | |
taylorza | 0:303768292f44 | 94 | void Raycaster::renderFrame() |
taylorza | 0:303768292f44 | 95 | { |
taylorza | 0:303768292f44 | 96 | int xd, yd; |
taylorza | 0:303768292f44 | 97 | int grid_x, grid_y; |
taylorza | 0:303768292f44 | 98 | float xcross_x, xcross_y; |
taylorza | 0:303768292f44 | 99 | float ycross_x, ycross_y; |
taylorza | 0:303768292f44 | 100 | int xmaze, ymaze; |
taylorza | 0:303768292f44 | 101 | float distance; |
taylorza | 0:303768292f44 | 102 | int tmcolumn; |
taylorza | 0:303768292f44 | 103 | uint8_t cellValue; |
taylorza | 0:303768292f44 | 104 | |
taylorza | 0:303768292f44 | 105 | int xview = FLOAT2INT(_playerX); |
taylorza | 0:303768292f44 | 106 | int yview = FLOAT2INT(_playerY); |
taylorza | 0:303768292f44 | 107 | |
taylorza | 0:303768292f44 | 108 | float columnAngle = _halfViewVolume; |
taylorza | 0:303768292f44 | 109 | float ainc2 = _ainc * 2; |
taylorza | 0:303768292f44 | 110 | Sliver *pSliver = _pSlivers; |
taylorza | 0:303768292f44 | 111 | for (int column = 0; column < _width; column += 2, columnAngle -= ainc2, pSliver++) |
taylorza | 0:303768292f44 | 112 | { |
taylorza | 0:303768292f44 | 113 | float radians = _playerViewAngle - columnAngle; |
taylorza | 0:303768292f44 | 114 | |
taylorza | 0:303768292f44 | 115 | int xdiff = FLOAT2INT(CELL_SIZE * sin(radians)); |
taylorza | 0:303768292f44 | 116 | int ydiff = FLOAT2INT(-CELL_SIZE * cos(radians)); |
taylorza | 0:303768292f44 | 117 | |
taylorza | 0:303768292f44 | 118 | if (xdiff == 0) xdiff = 1; |
taylorza | 0:303768292f44 | 119 | |
taylorza | 0:303768292f44 | 120 | float slope = (float)ydiff / xdiff; |
taylorza | 0:303768292f44 | 121 | if (slope == 0.0f) slope = 0.001f; |
taylorza | 0:303768292f44 | 122 | |
taylorza | 0:303768292f44 | 123 | int x = xview; |
taylorza | 0:303768292f44 | 124 | int y = yview; |
taylorza | 0:303768292f44 | 125 | |
taylorza | 0:303768292f44 | 126 | for(;;) |
taylorza | 0:303768292f44 | 127 | { |
taylorza | 0:303768292f44 | 128 | if (xdiff > 0) |
taylorza | 0:303768292f44 | 129 | { |
taylorza | 0:303768292f44 | 130 | grid_x = ((int)x & CELL_BIT_MASK) + CELL_SIZE; |
taylorza | 0:303768292f44 | 131 | } |
taylorza | 0:303768292f44 | 132 | else |
taylorza | 0:303768292f44 | 133 | { |
taylorza | 0:303768292f44 | 134 | grid_x = ((int)x & CELL_BIT_MASK) - 1; |
taylorza | 0:303768292f44 | 135 | } |
taylorza | 0:303768292f44 | 136 | |
taylorza | 0:303768292f44 | 137 | if (ydiff > 0) |
taylorza | 0:303768292f44 | 138 | { |
taylorza | 0:303768292f44 | 139 | grid_y = ((int)y & CELL_BIT_MASK) + CELL_SIZE; |
taylorza | 0:303768292f44 | 140 | } |
taylorza | 0:303768292f44 | 141 | else |
taylorza | 0:303768292f44 | 142 | { |
taylorza | 0:303768292f44 | 143 | grid_y = ((int)y & CELL_BIT_MASK) - 1; |
taylorza | 0:303768292f44 | 144 | } |
taylorza | 0:303768292f44 | 145 | |
taylorza | 0:303768292f44 | 146 | xcross_x = grid_x; |
taylorza | 0:303768292f44 | 147 | xcross_y = y + slope * (grid_x - x); |
taylorza | 0:303768292f44 | 148 | |
taylorza | 0:303768292f44 | 149 | ycross_x = x + (grid_y - y) / slope; |
taylorza | 0:303768292f44 | 150 | ycross_y = grid_y; |
taylorza | 0:303768292f44 | 151 | |
taylorza | 0:303768292f44 | 152 | xd = xcross_x - x; |
taylorza | 0:303768292f44 | 153 | yd = xcross_y - y; |
taylorza | 0:303768292f44 | 154 | int xdist = (xd * xd) + (yd * yd); |
taylorza | 0:303768292f44 | 155 | |
taylorza | 0:303768292f44 | 156 | xd = ycross_x - x; |
taylorza | 0:303768292f44 | 157 | yd = ycross_y - y; |
taylorza | 0:303768292f44 | 158 | int ydist = (xd * xd) + (yd * yd); |
taylorza | 0:303768292f44 | 159 | |
taylorza | 0:303768292f44 | 160 | if (xdist < ydist) |
taylorza | 0:303768292f44 | 161 | { |
taylorza | 0:303768292f44 | 162 | xmaze = (int)xcross_x >> CELL_SIZE_SHIFT; |
taylorza | 0:303768292f44 | 163 | ymaze = (int)xcross_y >> CELL_SIZE_SHIFT; |
taylorza | 0:303768292f44 | 164 | |
taylorza | 0:303768292f44 | 165 | x = xcross_x; |
taylorza | 0:303768292f44 | 166 | y = xcross_y; |
taylorza | 0:303768292f44 | 167 | |
taylorza | 0:303768292f44 | 168 | tmcolumn = (int)y & CELL_SIZE_MASK; |
taylorza | 0:303768292f44 | 169 | } |
taylorza | 0:303768292f44 | 170 | else |
taylorza | 0:303768292f44 | 171 | { |
taylorza | 0:303768292f44 | 172 | xmaze = (int)ycross_x >> CELL_SIZE_SHIFT; |
taylorza | 0:303768292f44 | 173 | ymaze = (int)ycross_y >> CELL_SIZE_SHIFT; |
taylorza | 0:303768292f44 | 174 | |
taylorza | 0:303768292f44 | 175 | x = ycross_x; |
taylorza | 0:303768292f44 | 176 | y = ycross_y; |
taylorza | 0:303768292f44 | 177 | |
taylorza | 0:303768292f44 | 178 | tmcolumn = (int)x & CELL_SIZE_MASK; |
taylorza | 0:303768292f44 | 179 | } |
taylorza | 0:303768292f44 | 180 | |
taylorza | 0:303768292f44 | 181 | cellValue = _pMap[xmaze + (ymaze * _mapWidth)]; |
taylorza | 0:303768292f44 | 182 | if (cellValue != 0) break; |
taylorza | 0:303768292f44 | 183 | } |
taylorza | 0:303768292f44 | 184 | |
taylorza | 0:303768292f44 | 185 | xd = x - xview; |
taylorza | 0:303768292f44 | 186 | yd = y - yview; |
taylorza | 0:303768292f44 | 187 | distance = sqrt(((xd * xd) + (yd * yd)) * cos(columnAngle)); |
taylorza | 0:303768292f44 | 188 | if (distance == 0) distance = 1; |
taylorza | 0:303768292f44 | 189 | |
taylorza | 0:303768292f44 | 190 | int height = _heightRatio / distance; |
taylorza | 0:303768292f44 | 191 | if (height == 0) height = 1; |
taylorza | 0:303768292f44 | 192 | |
taylorza | 0:303768292f44 | 193 | int bot = _viewDistanceTimesHeight / distance + _vertCenter; |
taylorza | 0:303768292f44 | 194 | int top = bot - height; |
taylorza | 0:303768292f44 | 195 | |
taylorza | 0:303768292f44 | 196 | int t = tmcolumn; |
taylorza | 0:303768292f44 | 197 | int dheight = height; |
taylorza | 0:303768292f44 | 198 | int iheight = CELL_SIZE; |
taylorza | 0:303768292f44 | 199 | float yratio = (float)CELL_SIZE / height; |
taylorza | 0:303768292f44 | 200 | |
taylorza | 0:303768292f44 | 201 | if (top < _top) |
taylorza | 0:303768292f44 | 202 | { |
taylorza | 0:303768292f44 | 203 | int clipBy = _top - top; |
taylorza | 0:303768292f44 | 204 | int clipRatio = (int)(clipBy * yratio); |
taylorza | 0:303768292f44 | 205 | dheight-= clipBy; |
taylorza | 0:303768292f44 | 206 | t += clipRatio << CELL_SIZE_SHIFT; |
taylorza | 0:303768292f44 | 207 | iheight -= clipRatio; |
taylorza | 0:303768292f44 | 208 | top = _top; |
taylorza | 0:303768292f44 | 209 | } |
taylorza | 0:303768292f44 | 210 | |
taylorza | 0:303768292f44 | 211 | if (bot >= _bottom) |
taylorza | 0:303768292f44 | 212 | { |
taylorza | 0:303768292f44 | 213 | int clipBy = bot - _bottom; |
taylorza | 0:303768292f44 | 214 | dheight -= clipBy; |
taylorza | 0:303768292f44 | 215 | iheight -= (int)(clipBy * yratio); |
taylorza | 0:303768292f44 | 216 | bot = _bottom; |
taylorza | 0:303768292f44 | 217 | } |
taylorza | 0:303768292f44 | 218 | |
taylorza | 0:303768292f44 | 219 | uint16_t color = 0xf800; |
taylorza | 0:303768292f44 | 220 | |
taylorza | 0:303768292f44 | 221 | color = _pPalette[cellValue]; |
taylorza | 0:303768292f44 | 222 | |
taylorza | 0:303768292f44 | 223 | pSliver->top = top; |
taylorza | 0:303768292f44 | 224 | pSliver->bottom = bot; |
taylorza | 0:303768292f44 | 225 | pSliver->color = color; |
taylorza | 0:303768292f44 | 226 | } |
taylorza | 0:303768292f44 | 227 | |
taylorza | 0:303768292f44 | 228 | int x = _left; |
taylorza | 0:303768292f44 | 229 | pSliver = _pSlivers; |
taylorza | 0:303768292f44 | 230 | for(int column = 0; column < _width; column += 2, x += 2, pSliver++) |
taylorza | 0:303768292f44 | 231 | { |
taylorza | 0:303768292f44 | 232 | _display.fillRect(x, _top, x + 1, pSliver->top, *_pPalette); |
taylorza | 0:303768292f44 | 233 | _display.fillRect(x, pSliver->top, x + 1, pSliver->bottom, pSliver->color); |
taylorza | 0:303768292f44 | 234 | _display.fillRect(x, pSliver->bottom, x + 1, _bottom, *_pPalette); |
taylorza | 0:303768292f44 | 235 | } |
taylorza | 0:303768292f44 | 236 | } |