comparison: components/u8g2/csrc/u8g2_intersection.c
components/u8g2/csrc/u8g2_intersection.c
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| 1 /* | |
| 2 | |
| 3 u8g2_intersection.c | |
| 4 | |
| 5 Intersection calculation, code taken from u8g_clip.c | |
| 6 | |
| 7 Universal 8bit Graphics Library (https://github.com/olikraus/u8g2/) | |
| 8 | |
| 9 Copyright (c) 2016, olikraus@gmail.com | |
| 10 All rights reserved. | |
| 11 | |
| 12 Redistribution and use in source and binary forms, with or without modification, | |
| 13 are permitted provided that the following conditions are met: | |
| 14 | |
| 15 * Redistributions of source code must retain the above copyright notice, this list | |
| 16 of conditions and the following disclaimer. | |
| 17 | |
| 18 * Redistributions in binary form must reproduce the above copyright notice, this | |
| 19 list of conditions and the following disclaimer in the documentation and/or other | |
| 20 materials provided with the distribution. | |
| 21 | |
| 22 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND | |
| 23 CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, | |
| 24 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
| 25 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
| 26 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR | |
| 27 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
| 28 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
| 29 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
| 30 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER | |
| 31 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
| 32 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
| 33 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF | |
| 34 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 35 | |
| 36 */ | |
| 37 | |
| 38 #include "u8g2.h" | |
| 39 | |
| 40 #ifdef __GNUC__ | |
| 41 #define U8G2_ALWAYS_INLINE __inline__ __attribute__((always_inline)) | |
| 42 #else | |
| 43 #define U8G2_ALWAYS_INLINE | |
| 44 #endif | |
| 45 | |
| 46 | |
| 47 #if defined(U8G2_WITH_INTERSECTION) || defined(U8G2_WITH_CLIP_WINDOW_SUPPORT) | |
| 48 | |
| 49 #ifdef OLD_VERSION_WITH_SYMETRIC_BOUNDARIES | |
| 50 | |
| 51 /* | |
| 52 intersection assumptions: | |
| 53 a1 <= a2 is always true | |
| 54 | |
| 55 minimized version | |
| 56 ---1----0 1 b1 <= a2 && b1 > b2 | |
| 57 -----1--0 1 b2 >= a1 && b1 > b2 | |
| 58 ---1-1--- 1 b1 <= a2 && b2 >= a1 | |
| 59 */ | |
| 60 | |
| 61 | |
| 62 /* | |
| 63 calculate the intersection between a0/a1 and v0/v1 | |
| 64 The intersection check returns one if the range of a0/a1 has an intersection with v0/v1. | |
| 65 The intersection check includes the boundary values v1 and a1. | |
| 66 | |
| 67 The following asserts will succeed: | |
| 68 assert( u8g2_is_intersection_decision_tree(4, 6, 7, 9) == 0 ); | |
| 69 assert( u8g2_is_intersection_decision_tree(4, 6, 6, 9) != 0 ); | |
| 70 assert( u8g2_is_intersection_decision_tree(6, 9, 4, 6) != 0 ); | |
| 71 assert( u8g2_is_intersection_decision_tree(7, 9, 4, 6) == 0 ); | |
| 72 */ | |
| 73 | |
| 74 //static uint8_t U8G2_ALWAYS_INLINE u8g2_is_intersection_decision_tree(u8g_uint_t a0, u8g_uint_t a1, u8g_uint_t v0, u8g_uint_t v1) | |
| 75 static uint8_t u8g2_is_intersection_decision_tree(u8g2_uint_t a0, u8g2_uint_t a1, u8g2_uint_t v0, u8g2_uint_t v1) | |
| 76 { | |
| 77 if ( v0 <= a1 ) | |
| 78 { | |
| 79 if ( v1 >= a0 ) | |
| 80 { | |
| 81 return 1; | |
| 82 } | |
| 83 else | |
| 84 { | |
| 85 if ( v0 > v1 ) | |
| 86 { | |
| 87 return 1; | |
| 88 } | |
| 89 else | |
| 90 { | |
| 91 return 0; | |
| 92 } | |
| 93 } | |
| 94 } | |
| 95 else | |
| 96 { | |
| 97 if ( v1 >= a0 ) | |
| 98 { | |
| 99 if ( v0 > v1 ) | |
| 100 { | |
| 101 return 1; | |
| 102 } | |
| 103 else | |
| 104 { | |
| 105 return 0; | |
| 106 } | |
| 107 } | |
| 108 else | |
| 109 { | |
| 110 return 0; | |
| 111 } | |
| 112 } | |
| 113 } | |
| 114 | |
| 115 #endif /* OLD_VERSION_WITH_SYMETRIC_BOUNDARIES */ | |
| 116 | |
| 117 | |
| 118 /* | |
| 119 version with asymetric boundaries. | |
| 120 a1 and v1 are excluded | |
| 121 v0 == v1 is not support end return 1 | |
| 122 */ | |
| 123 uint8_t u8g2_is_intersection_decision_tree(u8g2_uint_t a0, u8g2_uint_t a1, u8g2_uint_t v0, u8g2_uint_t v1) | |
| 124 { | |
| 125 if ( v0 < a1 ) // v0 <= a1 | |
| 126 { | |
| 127 if ( v1 > a0 ) // v1 >= a0 | |
| 128 { | |
| 129 return 1; | |
| 130 } | |
| 131 else | |
| 132 { | |
| 133 if ( v0 > v1 ) // v0 > v1 | |
| 134 { | |
| 135 return 1; | |
| 136 } | |
| 137 else | |
| 138 { | |
| 139 return 0; | |
| 140 } | |
| 141 } | |
| 142 } | |
| 143 else | |
| 144 { | |
| 145 if ( v1 > a0 ) // v1 >= a0 | |
| 146 { | |
| 147 if ( v0 > v1 ) // v0 > v1 | |
| 148 { | |
| 149 return 1; | |
| 150 } | |
| 151 else | |
| 152 { | |
| 153 return 0; | |
| 154 } | |
| 155 } | |
| 156 else | |
| 157 { | |
| 158 return 0; | |
| 159 } | |
| 160 } | |
| 161 } | |
| 162 | |
| 163 | |
| 164 | |
| 165 /* upper limits are not included (asymetric boundaries) */ | |
| 166 uint8_t u8g2_IsIntersection(u8g2_t *u8g2, u8g2_uint_t x0, u8g2_uint_t y0, u8g2_uint_t x1, u8g2_uint_t y1) | |
| 167 { | |
| 168 if ( u8g2_is_intersection_decision_tree(u8g2->user_y0, u8g2->user_y1, y0, y1) == 0 ) | |
| 169 return 0; | |
| 170 | |
| 171 return u8g2_is_intersection_decision_tree(u8g2->user_x0, u8g2->user_x1, x0, x1); | |
| 172 } | |
| 173 | |
| 174 | |
| 175 #endif /* U8G2_WITH_INTERSECTION */ | |
| 176 |
