Pokitto-Raycasting/general.hpp
2018-09-08 14:30:03 +02:00

134 lines
2.8 KiB
C++

/**
General definitions for Pokitto raycasting demos.
author: Miloslav "drummyfish" Ciz
license: CC0 1.0
*/
#ifndef RAYCAST_DEMO_GENERAL_HPP
#define RAYCAST_DEMO_GENERAL_HPP
#include "stdio.h" // for debugging raycastlibg
#define VERTICAL_FOV UNITS_PER_SQUARE // redefine camera vertical FOV
#include "raycastlib.h"
#include "Pokitto.h"
Pokitto::Core pokitto;
#define SCREEN_WIDTH 110
#define SCREEN_HEIGHT 88
#define MIDDLE_ROW (SCREEN_HEIGHT / 2)
#define MIDDLE_COLUMN (SCREEN_WIDTH / 2)
#ifndef SUBSAMPLE
#define SUBSAMPLE 2
#endif
#define SUBSAMPLED_WIDTH (SCREEN_WIDTH / SUBSAMPLE)
#define TRANSPARENT_COLOR 0b00000111
Unit zBuffer[SUBSAMPLED_WIDTH]; ///< 1D z-buffer for visibility determination.
/**
Gets (the index of) color by specified RGB components.
@param r red, 3 bits (0 to 7)
@param g green, 3 bits (0 to 7)
@param b blue, 2 bits (0 to 3)
@return palette index of the color
*/
inline uint8_t rgbToIndex(uint8_t r, uint8_t g, uint8_t b)
{
return (r & 0b00000111) | ((g & 0b00000111) << 3) | ((b & 0b00000011) << 6);
}
/**
Adds given intensity to a color.
@param color input color
@param intensity intensity to add, 3 bit (0 to 7)
@return new color
*/
inline uint8_t addIntensity(uint8_t color, int intensity)
{
uint8_t r = color & 0b00000111;
uint8_t g = (color & 0b00111000) >> 3;
uint8_t b = (color & 0b11000000) >> 6;
if (intensity >= 0)
{
r += intensity;
r = r > 7 ? 7 : r;
g += intensity;
g = g > 7 ? 7 : g;
b += intensity / 2;
b = b > 3 ? 3 : b;
}
else
{
intensity *= -1;
r = (intensity > r) ? 0 : r - intensity;
g = (intensity > g) ? 0 : g - intensity;
intensity /= 2;
b = intensity > b ? 0 : b - intensity;
}
return rgbToIndex(r,g,b);
}
/**
Samples an image by normalized coordinates - each coordinate is in range
0 to UNITS_PER_SQUARE (from raycastlib).
*/
inline uint8_t sampleImage(const unsigned char *image, Unit x, Unit y)
{
// TODO: optimize
x = wrap(x,UNITS_PER_SQUARE);
y = wrap(y,UNITS_PER_SQUARE);
int32_t index =
image[1] * ((image[1] * x) / UNITS_PER_SQUARE) + (image[0] * y) /
UNITS_PER_SQUARE;
return image[2 + index];
}
void inline drawSprite(const unsigned char *sprite, int16_t x, int16_t y, Unit depth, int16_t size)
{
// TODO: optimize
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 / SUBSAMPLE] <= depth)
continue;
for (Unit j = max(-1 * y,0); j < jTo; ++j)
{
c = sampleImage(sprite,(i * UNITS_PER_SQUARE) / size,(j * UNITS_PER_SQUARE) / size);
if (c != TRANSPARENT_COLOR)
pokitto.display.drawPixel(xPos,y + j,c);
}
}
}
#endif