diff options
| -rw-r--r-- | src/display.cc | 35 | ||||
| -rw-r--r-- | src/display.h | 6 |
2 files changed, 38 insertions, 3 deletions
diff --git a/src/display.cc b/src/display.cc index 0f7a56a..1fbe190 100644 --- a/src/display.cc +++ b/src/display.cc @@ -70,6 +70,10 @@ void Display::update() { if (status == RUNNING) { if (current_anim->type == AnimationType::TEXT) { + + /* + * Scroll display contents to the left/right + */ if (current_anim->direction == 0) { for (i = 0; i < 7; i++) { disp_buf[i] = disp_buf[i+1]; @@ -80,6 +84,9 @@ void Display::update() { } } + /* + * Load current character + */ glyph_addr = (uint8_t *)pgm_read_ptr(&font[current_anim->data[str_pos]]); glyph_len = pgm_read_byte(&glyph_addr[0]); char_pos++; @@ -89,9 +96,13 @@ void Display::update() { if (current_anim->direction == 0) str_pos++; else - str_pos--; + str_pos--; // may underflow, but that's okay } + /* + * Append one character column (or whitespace if we are + * between two characters) + */ if (current_anim->direction == 0) { if (char_pos == 0) { disp_buf[7] = 0xff; // whitespace @@ -112,7 +123,13 @@ void Display::update() { } str_pos += 8; } + if (current_anim->direction == 0) { + /* + * Check whether we reached the end of the pattern + * (that is, we're in the last chunk and reached the + * remaining pattern length) + */ if ((str_chunk == ((current_anim->length - 1) / 128)) && (str_pos > ((current_anim->length - 1) % 128))) { str_chunk = 0; @@ -124,13 +141,26 @@ void Display::update() { if (current_anim->length > 128) { storage.loadChunk(str_chunk, current_anim->data); } + /* + * Otherwise, check whether the pattern is split into + * several chunks and we reached the end of the chunk + * kept in current_anim->data + */ } else if ((current_anim->length > 128) && (str_pos >= 128)) { str_pos = 0; str_chunk++; storage.loadChunk(str_chunk, current_anim->data); } } else { + /* + * In this branch we keep doing str_pos--, so check for + * underflow + */ if (str_pos >= 128) { + /* + * Check whether we reached the end of the pattern + * (and whether we need to load a new chunk) + */ if (str_chunk == 0) { if (current_anim->length > 128) { str_chunk = (current_anim->length - 1) / 128; @@ -143,6 +173,9 @@ void Display::update() { } else { str_pos = (current_anim->length - 1) % 128; } + /* + * Otherwise, we reached the end of the active chunk + */ } else { str_chunk--; storage.loadChunk(str_chunk, current_anim->data); diff --git a/src/display.h b/src/display.h index aac64dd..ef133a0 100644 --- a/src/display.h +++ b/src/display.h @@ -199,8 +199,10 @@ class Display { /** * Update display content. * Checks current_anim->speed and current_anim->type and scrolls - * the text / advances a frame when appropriate. Does nothing - * otherwise. + * the text / advances a frame when appropriate. Also uses + * Storage::loadChunk() to load the next 128 pattern bytes if + * current_anim->length is greater than 128 and the end of the + * 128 byte pattern buffer is reached. */ void update(void); |