diff options
Diffstat (limited to 'bitmap.h')
| -rw-r--r-- | bitmap.h | 38 |
1 files changed, 38 insertions, 0 deletions
@@ -10,6 +10,8 @@ #include <ostream> #include <cassert> +#include "bitfont.h" + #define COLORMIX_OVERFLOW_CHECK //// T is some unsigned integer @@ -95,6 +97,10 @@ public: // Do not use float-point pixels, or this routine will break. void write_plain_ppm(std::ostream &out) const; + + // Draw text on the image. Supports limited visual ASCII characters. + void print(const std::string &s, const pixel<T> &color, + unsigned x, unsigned y, unsigned scale = 1, double alpha = 1.0); }; template<typename T> @@ -111,6 +117,38 @@ void bitmap<T>::write_plain_ppm(std::ostream &out) const { } } +template<typename T> +void bitmap<T>::print(const std::string &s, const pixel<T> &color, + unsigned x, unsigned y, unsigned scale, double alpha) { + assert(alpha >= 0); + assert(alpha <= 1); + const unsigned char_w = 8 * scale, char_h = 13 * scale; // char width and height + size_t n = 0; + for (const auto &c: s) { + unsigned int idx = c - 32U; + if (idx >= 95) idx = 1; // replace invisible chars with '!' + + const unsigned char_x = x + n * char_w + ((n > 1) ? ((n - 1) * scale) : 0); + const unsigned char_y = y; + + // char size is 13x8, stored line by line, from the bottom line to the top line + // every line is represented in a single byte + // in every byte, from MSB to LSB, the pixel goes from left to right + + for (unsigned i = 0; i < char_w; ++i) { + for (unsigned j = 0; j < char_h; ++j) { + // downscale (i, j) to pos on char bitmap i -> i/scale, j -> j/scale + if (rasters[idx][12 - j / scale] & (1U << (7U - i / scale))) { + const auto pen_x = char_x + i, pen_y = char_y + j; + if (pen_x >= width || pen_y >= height) continue; + image(pen_x, pen_y) = mix(image(pen_x, pen_y), color, 1.0 - alpha, alpha); + } + } + } + ++n; + } +} + using bitmap8b = bitmap<uint8_t>; |