src/main/osd/osd_screen.c

   1 /*
   2  * This file is part of Cleanflight.
   3  *
   4  * Cleanflight is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Cleanflight is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <stdbool.h>
  19 #include <stdlib.h>
  20 #include <stdint.h>
  21 #include <string.h>
  22
  23 #include <platform.h>
  24 #include "build/debug.h"
  25
  26 #include "drivers/video_textscreen.h"
  27 #include "common/utils.h"
  28
  29 #include "osd/osd_element.h"
  30 #include "osd/osd_screen.h"
  31
  32
  33 textScreen_t osdTextScreen;
  34
  35 typedef struct osdCursor_s {
  36     osdCoordVal_t x;
  37     osdCoordVal_t y;
  38 } osdCursor_t;
  39
  40 static osdCursor_t cursor = {0, 0};
  41
  42 static uint16_t osdCalculateBufferOffset(osdCoordVal_t x, osdCoordVal_t y) {
  43     osdCoordVal_t yy;
  44     if (y >= 0) {
  45         // positive y = top aligned
  46         yy = y;
  47     } else {
  48         // negative y = bottom aligned
  49         yy = osdTextScreen.height + y;
  50
  51         // prevent bottom aligned  PAL screen coordinate from appearing off-screen when NTSC is used
  52         // e.g. when PAL rows = 16, and Y = -15 it's OK, but when NTSC with 13 rows is used a negative value is calculated for yy.
  53         if (yy < 0) {
  54             yy = 0;
  55         }
  56     }
  57     uint16_t offset = (yy * osdTextScreen.width) + x;
  58     return offset;
  59 }
  60 // Does not move the cursor.
  61 void osdSetCharacterAtPosition(osdCoordVal_t x, osdCoordVal_t y, char c)
  62 {
  63     uint8_t mappedCharacter = asciiToFontMapping[(uint8_t)c];
  64
  65     uint16_t offset = osdCalculateBufferOffset(x,y);
  66     textScreenBuffer[offset] = mappedCharacter;
  67 }
  68
  69 // Does not move the cursor.
  70 void osdSetRawCharacterAtPosition(osdCoordVal_t x, osdCoordVal_t y, char c)
  71 {
  72     uint16_t offset = osdCalculateBufferOffset(x,y);
  73     textScreenBuffer[offset] = c;
  74 }
  75
  76 void osdResetCursor(void)
  77 {
  78     cursor.x = 0;
  79     cursor.y = 0;
  80 }
  81
  82 void osdSetCursor(osdCoordVal_t x, osdCoordVal_t y)
  83 {
  84     cursor.x = x;
  85     cursor.y = y;
  86 }
  87
  88 // software cursor, handles line wrapping and row wrapping, resets to 0,0 when the end of the screen is reached
  89 static void osdAdvanceCursor(void)
  90 {
  91     cursor.x++;
  92     if (cursor.x >= osdTextScreen.width) {
  93         cursor.y++;
  94         cursor.x = 0;
  95         if (cursor.y > osdTextScreen.height) {
  96             cursor.y = 0;
  97         }
  98     }
  99 }
 100
 101 void osdPrint(char *message)
 102 {
 103     uint8_t *charPtr = (uint8_t *)message;
 104     bool escape = false;
 105     while(*charPtr) {
 106         if (!escape) {
 107             if (*charPtr == 0xff) {
 108                 escape = true;
 109                 charPtr++;
 110                 continue;
 111             }
 112         }
 113         if (escape) {
 114             osdSetRawCharacterAtPosition(cursor.x, cursor.y, *charPtr);
 115             escape = false;
 116         } else {
 117             osdSetCharacterAtPosition(cursor.x, cursor.y, *charPtr);
 118         }
 119         osdAdvanceCursor();
 120
 121         charPtr++;
 122     }
 123 }
 124
 125 void osdPrintAt(osdCoordVal_t x, osdCoordVal_t y, char *message)
 126 {
 127     osdSetCursor(x, y);
 128     osdPrint(message);
 129 }
 130
 131 void osdSetTextScreen(textScreen_t *textScreen)
 132 {
 133     osdTextScreen = *textScreen;
 134 }
 135
 136 void osdClearScreen(void)
 137 {
 138     uint8_t mappedSpaceCharacter = asciiToFontMapping[(uint8_t)' '];
 139
 140     int offset = 0;
 141     for (int y = 0; y < osdTextScreen.height; y++) {
 142         for (int x = 0; x < osdTextScreen.width; x++) {
 143             textScreenBuffer[offset++] = mappedSpaceCharacter;
 144         }
 145     }
 146 }