From c25fdd486ba4ff43c1b263b071d1dee3a4c1980c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Miloslav=20=C4=8C=C3=AD=C5=BE?= Date: Wed, 12 Sep 2018 12:09:34 +0200 Subject: [PATCH] Fix division by 0 --- raycastlib.h | 2 +- testSDL.c | 152 +++++++++++++++++++++++++++++++++++++++------------ 2 files changed, 117 insertions(+), 37 deletions(-) diff --git a/raycastlib.h b/raycastlib.h index 1e6546e..c9d096b 100644 --- a/raycastlib.h +++ b/raycastlib.h @@ -1184,7 +1184,7 @@ PixelInfo mapToScreen(Vector2D worldPosition, Unit height, Camera camera) (result.depth * sinInt(HORIZONTAL_FOV_HALF)) / (cos == 0 ? 1 : cos); // sin/cos = tan - result.position.x = (a * middleColumn) / b; + result.position.x = (a * middleColumn) / (b == 0 ? 1 : b); result.position.x = middleColumn - result.position.x; return result; diff --git a/testSDL.c b/testSDL.c index 0cf9ec3..cfb7049 100644 --- a/testSDL.c +++ b/testSDL.c @@ -1,5 +1,5 @@ /* - Raycasting SDL test. + Raycasting SDL test. This is a port of my Pokitto demo. author: Miloslav Ciz license: CC0 @@ -25,6 +25,10 @@ #define SCREEN_HEIGHT 480 #define MIDDLE_ROW (SCREEN_HEIGHT / 2) +#define TRANSPARENT_COLOR 0b00000111 + +#define max(a,b) ((a) > (b) ? (a) : (b)) + #define KEYS 6 #define KEY_UP 0 #define KEY_RIGHT 1 @@ -49,7 +53,7 @@ typedef struct Unit mPixelSize; } Sprite; -#define RGB(r,g,b) (0 | ((r << 24) | (g << 16) | (b << 8))) +uint32_t palette[256]; #define SPRITES 7 #define SPRITE_MAX_DISTANCE 5 * UNITS_PER_SQUARE @@ -750,12 +754,15 @@ Unit floorHeightAt(int16_t x, int16_t y) if (x >= 0 && x < LEVEL_X_RES && y >= 0 && y < LEVEL_Y_RES) return (levelFloor[(LEVEL_Y_RES - y -1) * LEVEL_X_RES + x] * UNITS_PER_SQUARE) / 8; - return 0; + int a = absVal(x - LEVEL_X_RES / 2) - LEVEL_X_RES / 2; + int b = absVal(y - LEVEL_Y_RES / 2) - LEVEL_Y_RES / 2; + + return (a > b ? a : b) * UNITS_PER_SQUARE; } Unit ceilingHeightAt(int16_t x, int16_t y) { - signed char v = 127; + int v = 1024; if (x >= 0 && x < LEVEL_X_RES && y >= 0 && y < LEVEL_Y_RES) v = levelCeiling[(LEVEL_Y_RES - y -1) * LEVEL_X_RES + x]; @@ -763,6 +770,52 @@ Unit ceilingHeightAt(int16_t x, int16_t y) return (v * UNITS_PER_SQUARE) / 8; } +/** + Draws a scaled sprite on screen in an optimized way. The sprite has to be + square in resolution. +*/ +void drawSpriteSquare(const unsigned char *sprite, int16_t x, int16_t y, Unit depth, int16_t size) +{ + if (size < 0 || size > 200 || // let's not mess up with the incoming array + sprite[0] != sprite[1]) // only draw square sprites + return; + + int16_t samplingIndices[size]; + + // optimization: precompute the indices + + for (Unit i = 0; i < size; ++i) + samplingIndices[i] = (i * sprite[0]) / size; + + x -= size / 2; + y -= size / 2; + + Unit step = UNITS_PER_SQUARE / size; + + uint8_t c; + + int16_t jTo = size - max(0,y + size - 88); + int16_t iTo = size - max(0,x + size - 110); + + for (Unit i = max(-1 * x,0); i < iTo; ++i) + { + int16_t xPos = x + i; + + if (zBuffer[xPos] <= depth) + continue; + + int16_t columnLocation = 2 + samplingIndices[i] * sprite[0]; + + for (Unit j = max(-1 * y,0); j < jTo; ++j) + { + c = sprite[columnLocation + samplingIndices[j]]; + + if (c != TRANSPARENT_COLOR) + pixels[j * SCREEN_WIDTH + i] = c | c | c; + } + } +} + /** Function for drawing a single pixel (like fragment shader). Bottleneck => should be as fast as possible. @@ -774,33 +827,30 @@ void pixelFunc(PixelInfo *pixel) uint8_t c; - Unit depth = pixel->depth - UNITS_PER_SQUARE * 3; - depth = depth > 0 ? depth : 1; - - int intensity = 7 - (depth * 7) / (UNITS_PER_SQUARE * 5); - - if (intensity < 0) - intensity = 0; - -//intensity = 5; - if (pixel->isWall) - { - if ((pixel->hit.direction == 0 || pixel->hit.direction == 2)) - intensity -= 2; - - if (intensity < 0) - intensity = 0; - c = sampleImage(textures[pixel->hit.type],pixel->hit.textureCoord,pixel->textureCoordY); - c = addIntensity(c,intensity - 3); - } else - c = pixel->isFloor ? - rgbToIndex(intensity/2,intensity,intensity/3) : - rgbToIndex(intensity,intensity/2,0); + c = pixel->isFloor ? 0b00010001 : 0b00001010; - pixels[pixel->position.y * SCREEN_WIDTH + pixel->position.x] = RGB( (c & 0b00000111) * 36, ((c & 0b00111000) >> 3) * 36 , ((c & 0b11000000) >> 6) * 85 ); + int intensity = pixel->depth - 8 * UNITS_PER_SQUARE; + intensity = intensity < 0 ? 0 : intensity; + intensity = (intensity * 32) / UNITS_PER_SQUARE; + + int32_t color = palette[c]; + + int32_t r = ((color & 0xFF000000) >> 24) - intensity; + r = r > 0 ? r : 0; + r = r << 24; + + int32_t g = ((color & 0x00FF0000) >> 16) - intensity; + g = g > 0 ? g : 0; + g = g << 16; + + int32_t b = ((color & 0x0000FF00) >> 8) - intensity; + b = b > 0 ? b : 0; + b = b << 8; + + pixels[pixel->position.y * SCREEN_WIDTH + pixel->position.x] = r | g | b; } void draw() @@ -808,16 +858,13 @@ void draw() RayConstraints c; c.maxHits = 16; -// c.maxSteps = 10; -c.maxSteps = 20; + c.maxSteps = 20; c.computeTextureCoords = 1; render(camera,floorHeightAt,ceilingHeightAt,textureAt,pixelFunc,c); Unit previousDepth; - // draw sprites - for (uint8_t i = 0; i < SPRITES; ++i) { // use Chebyshew distance instead Euclidean, it's faster @@ -828,6 +875,20 @@ c.maxSteps = 20; continue; PixelInfo pos = mapToScreen(sprites[i].mPosition,sprites[i].mHeight,camera); + + if (pos.depth > 0) + drawSpriteSquare(sprites[i].mImage,pos.position.x,pos.position.y, + pos.depth,perspectiveScale(sprites[i].mPixelSize,pos.depth)); + + /* trick: sort the sprites by distance with bubble sort as we draw - the + order will be correct in a few frames */ + if (i != 0 && pos.depth > previousDepth) + { + Sprite tmp = sprites[i]; + sprites[i] = sprites[i - 1]; + sprites[i - 1] = tmp; + } + previousDepth = pos.depth; } } @@ -837,17 +898,36 @@ int main() for (int i = 0; i < SCREEN_WIDTH; ++i) zBuffer[i] = 0; - camera.position.x = 5; - camera.position.y = 5; + for (uint8_t r = 0; r < 8; ++r) + for (uint8_t g = 0; g < 8; ++g) + for (uint8_t b = 0; b < 4; ++b) + palette[rgbToIndex(r,g,b)] = ((36 * r) << 24) | ((36 * g) << 16) | ((85 * b) << 8); + + #define placeSprite(i,s,X,Y,z,n)\ + sprites[i].mImage = s;\ + sprites[i].mPosition.x = X * UNITS_PER_SQUARE;\ + sprites[i].mPosition.y = Y * UNITS_PER_SQUARE;\ + sprites[i].mHeight = z;\ + sprites[i].mPixelSize = n; + + placeSprite(0,sprite1,10,5,1,100); + placeSprite(1,sprite1,14,5,1,100); + placeSprite(2,sprite2,15,19,1,200); + placeSprite(3,sprite3,8,2,1,300); + placeSprite(4,sprite3,20,5,1,300); + placeSprite(5,sprite3,26,18,1,300); + placeSprite(6,sprite3,16,12,1,300); + + #undef placeSprite + + camera.position.x = UNITS_PER_SQUARE * 5; + camera.position.y = UNITS_PER_SQUARE * 4; camera.shear = 0; camera.direction = 0; camera.height = UNITS_PER_SQUARE * 2; camera.resolution.x = SCREEN_WIDTH; camera.resolution.y = SCREEN_HEIGHT; - for (int i = 0; i < KEYS; ++i) - keys[i] = 0; - SDL_Window *window = SDL_CreateWindow("raycasting", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN); SDL_Renderer *renderer = SDL_CreateRenderer(window,-1,0); SDL_Texture *texture = SDL_CreateTexture(renderer,SDL_PIXELFORMAT_RGBX8888, SDL_TEXTUREACCESS_STATIC, SCREEN_WIDTH, SCREEN_HEIGHT);