MBED port of the Physacs library
README.md@1:ebc0214989c0, 21 months ago (annotated)
- Committer:
- jstephens78
- Date:
- Mon Dec 05 19:27:37 2022 +0000
- Revision:
- 1:ebc0214989c0
- Parent:
- 0:e39efa4f4f58
Update README, add MBED example
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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jstephens78 | 0:e39efa4f4f58 | 1 | <img src="https://github.com/victorfisac/Physac/blob/master/icon/physac_256x256.png"> |
jstephens78 | 0:e39efa4f4f58 | 2 | |
jstephens78 | 1:ebc0214989c0 | 3 | # Physac-MBED |
jstephens78 | 1:ebc0214989c0 | 4 | This is a port of the Physac physics library to the MBED platform. |
jstephens78 | 1:ebc0214989c0 | 5 | |
jstephens78 | 1:ebc0214989c0 | 6 | ## Resource Usage |
jstephens78 | 1:ebc0214989c0 | 7 | The following outlines are based on defaults settings described under |
jstephens78 | 1:ebc0214989c0 | 8 | [##Modifications], and can be used to gauge resource demands of using Physac-MBED: |
jstephens78 | 1:ebc0214989c0 | 9 | - Each `PhysicsBody` requires 172 bytes of memory. Unless calling PhysicsShatter, |
jstephens78 | 1:ebc0214989c0 | 10 | these are always generated by user. |
jstephens78 | 1:ebc0214989c0 | 11 | - Each `PhysicsManifold` requires 56 bytes. These are generated internally during |
jstephens78 | 1:ebc0214989c0 | 12 | collisions to represent how the PhysicsBodys are interacting. |
jstephens78 | 1:ebc0214989c0 | 13 | |
jstephens78 | 1:ebc0214989c0 | 14 | ## Modifications |
jstephens78 | 1:ebc0214989c0 | 15 | The original Physac library was altered in the following ways to get running and |
jstephens78 | 1:ebc0214989c0 | 16 | to reduce footprint: |
jstephens78 | 1:ebc0214989c0 | 17 | - `PHYSAC_MAX_BODIES` was set to 16 |
jstephens78 | 1:ebc0214989c0 | 18 | - `PHYSAC_MAX_MANIFOLDS` was set to 96 |
jstephens78 | 1:ebc0214989c0 | 19 | - `PHYSAC_MAX_VERTICES` was set to 4 |
jstephens78 | 1:ebc0214989c0 | 20 | - `PHYSAC_CIRCLE_VERTICES` was set to 12 |
jstephens78 | 1:ebc0214989c0 | 21 | |
jstephens78 | 1:ebc0214989c0 | 22 | Physac-MBED can represent only collision shapes which are triangles, rectangles, |
jstephens78 | 1:ebc0214989c0 | 23 | or circles in its out-of-the-box configuration. |
jstephens78 | 1:ebc0214989c0 | 24 | |
jstephens78 | 1:ebc0214989c0 | 25 | ## Using Physac |
jstephens78 | 1:ebc0214989c0 | 26 | A simple demo using Physac-MBED to simulate objects and render them to a uLCD |
jstephens78 | 1:ebc0214989c0 | 27 | display: |
jstephens78 | 1:ebc0214989c0 | 28 | ```c++ |
jstephens78 | 1:ebc0214989c0 | 29 | #include "mbed.h" |
jstephens78 | 1:ebc0214989c0 | 30 | #include "uLCD_4DGL.h" |
jstephens78 | 1:ebc0214989c0 | 31 | |
jstephens78 | 1:ebc0214989c0 | 32 | #define PHYSAC_NO_THREADS |
jstephens78 | 1:ebc0214989c0 | 33 | #define PHYSAC_STANDALONE |
jstephens78 | 1:ebc0214989c0 | 34 | #define PHYSAC_IMPLEMENTATION |
jstephens78 | 1:ebc0214989c0 | 35 | #define _STDBOOL_H |
jstephens78 | 1:ebc0214989c0 | 36 | #include "physac.h" |
jstephens78 | 1:ebc0214989c0 | 37 | |
jstephens78 | 1:ebc0214989c0 | 38 | uLCD_4DGL uLCD(p9,p10,p30); |
jstephens78 | 1:ebc0214989c0 | 39 | |
jstephens78 | 1:ebc0214989c0 | 40 | int main(void) |
jstephens78 | 1:ebc0214989c0 | 41 | { |
jstephens78 | 1:ebc0214989c0 | 42 | uLCD.baudrate(BAUD_3000000); |
jstephens78 | 1:ebc0214989c0 | 43 | wait(.05); |
jstephens78 | 1:ebc0214989c0 | 44 | |
jstephens78 | 1:ebc0214989c0 | 45 | int screenWidth = 128; |
jstephens78 | 1:ebc0214989c0 | 46 | int screenHeight = 128; |
jstephens78 | 1:ebc0214989c0 | 47 | PhysicsBody floor = CreatePhysicsBodyRectangle((Vector2) { |
jstephens78 | 1:ebc0214989c0 | 48 | screenWidth/2, screenHeight - 4 |
jstephens78 | 1:ebc0214989c0 | 49 | }, screenWidth - 2, 4, 100); |
jstephens78 | 1:ebc0214989c0 | 50 | floor->enabled = false; // make object static |
jstephens78 | 1:ebc0214989c0 | 51 | |
jstephens78 | 1:ebc0214989c0 | 52 | // Defines which objects to create in the demo, and their initial properties |
jstephens78 | 1:ebc0214989c0 | 53 | // { x, y, density, rot, v_x, v_y } |
jstephens78 | 1:ebc0214989c0 | 54 | const size_t objs_n = 5; |
jstephens78 | 1:ebc0214989c0 | 55 | size_t objs_rect_n = 4; |
jstephens78 | 1:ebc0214989c0 | 56 | float objs_init[objs_n][6] = { |
jstephens78 | 1:ebc0214989c0 | 57 | { 48, 0, 10, PHYSAC_PI / 4, 0, 0 }, |
jstephens78 | 1:ebc0214989c0 | 58 | { 48, 64, 10, 0, 0, 0 }, |
jstephens78 | 1:ebc0214989c0 | 59 | { 92, 0, 10, 0, 0, 0 }, |
jstephens78 | 1:ebc0214989c0 | 60 | { 80, 48, 10, PHYSAC_PI / 4, 0, 0 }, |
jstephens78 | 1:ebc0214989c0 | 61 | { 256, 0, 30, 0, -.75, -.5 }, |
jstephens78 | 1:ebc0214989c0 | 62 | }; |
jstephens78 | 1:ebc0214989c0 | 63 | PhysicsBody objs[objs_n]; |
jstephens78 | 1:ebc0214989c0 | 64 | |
jstephens78 | 1:ebc0214989c0 | 65 | // Create demo objects |
jstephens78 | 1:ebc0214989c0 | 66 | for (int i = 0; i < objs_n; i++) { |
jstephens78 | 1:ebc0214989c0 | 67 | if (i < objs_rect_n) { |
jstephens78 | 1:ebc0214989c0 | 68 | objs[i] = CreatePhysicsBodyRectangle((Vector2) { |
jstephens78 | 1:ebc0214989c0 | 69 | objs_init[i][0], objs_init[i][1] |
jstephens78 | 1:ebc0214989c0 | 70 | }, 24, 24, objs_init[i][2]); |
jstephens78 | 1:ebc0214989c0 | 71 | } else { |
jstephens78 | 1:ebc0214989c0 | 72 | objs[i] = CreatePhysicsBodyCircle((Vector2) { |
jstephens78 | 1:ebc0214989c0 | 73 | objs_init[i][0], objs_init[i][1] |
jstephens78 | 1:ebc0214989c0 | 74 | }, 12, objs_init[i][2]); |
jstephens78 | 1:ebc0214989c0 | 75 | } |
jstephens78 | 1:ebc0214989c0 | 76 | SetPhysicsBodyRotation(objs[i], objs_init[i][3]); |
jstephens78 | 1:ebc0214989c0 | 77 | objs[i]->velocity.x = objs_init[i][4]; |
jstephens78 | 1:ebc0214989c0 | 78 | objs[i]->velocity.y = objs_init[i][5]; |
jstephens78 | 1:ebc0214989c0 | 79 | } |
jstephens78 | 1:ebc0214989c0 | 80 | |
jstephens78 | 1:ebc0214989c0 | 81 | // Simulation Loop |
jstephens78 | 1:ebc0214989c0 | 82 | Timer timer; |
jstephens78 | 1:ebc0214989c0 | 83 | timer.start(); |
jstephens78 | 1:ebc0214989c0 | 84 | |
jstephens78 | 1:ebc0214989c0 | 85 | // Time per step in ms |
jstephens78 | 1:ebc0214989c0 | 86 | deltaTime = 2.5; |
jstephens78 | 1:ebc0214989c0 | 87 | |
jstephens78 | 1:ebc0214989c0 | 88 | while (true) { |
jstephens78 | 1:ebc0214989c0 | 89 | float dt = timer.read() * 1000; |
jstephens78 | 1:ebc0214989c0 | 90 | timer.reset(); |
jstephens78 | 1:ebc0214989c0 | 91 | |
jstephens78 | 1:ebc0214989c0 | 92 | // In this demo, rendering takes orders of magnitudes longer than |
jstephens78 | 1:ebc0214989c0 | 93 | // physics takes to compute. So we run several steps per frame. |
jstephens78 | 1:ebc0214989c0 | 94 | for (int i = 0; i < 8; i++) { |
jstephens78 | 1:ebc0214989c0 | 95 | PhysicsStep(); |
jstephens78 | 1:ebc0214989c0 | 96 | } |
jstephens78 | 1:ebc0214989c0 | 97 | float phys_time = timer.read() * 1000; |
jstephens78 | 1:ebc0214989c0 | 98 | |
jstephens78 | 1:ebc0214989c0 | 99 | // Draw physics bodies |
jstephens78 | 1:ebc0214989c0 | 100 | uLCD.cls(); |
jstephens78 | 1:ebc0214989c0 | 101 | int bodiesCount = GetPhysicsBodiesCount(); |
jstephens78 | 1:ebc0214989c0 | 102 | for (int i = 0; i < bodiesCount; i++) { |
jstephens78 | 1:ebc0214989c0 | 103 | PhysicsBody body = GetPhysicsBody(i); |
jstephens78 | 1:ebc0214989c0 | 104 | |
jstephens78 | 1:ebc0214989c0 | 105 | if (body != NULL) { |
jstephens78 | 1:ebc0214989c0 | 106 | int vertexCount = GetPhysicsShapeVerticesCount(i); |
jstephens78 | 1:ebc0214989c0 | 107 | for (int j = 0; j < vertexCount; j++) { |
jstephens78 | 1:ebc0214989c0 | 108 | // Get physics bodies shape vertices to draw lines |
jstephens78 | 1:ebc0214989c0 | 109 | // Note: GetPhysicsShapeVertex() already calculates rotation transformations |
jstephens78 | 1:ebc0214989c0 | 110 | Vector2 vertexA = GetPhysicsShapeVertex(body, j); |
jstephens78 | 1:ebc0214989c0 | 111 | |
jstephens78 | 1:ebc0214989c0 | 112 | int jj = (((j + 1) < vertexCount) ? (j + 1) : 0); // Get next vertex or first to close the shape |
jstephens78 | 1:ebc0214989c0 | 113 | Vector2 vertexB = GetPhysicsShapeVertex(body, jj); |
jstephens78 | 1:ebc0214989c0 | 114 | |
jstephens78 | 1:ebc0214989c0 | 115 | uLCD.line(vertexA.x, vertexA.y, vertexB.x, vertexB.y, GREEN); // Draw a line between two vertex positions |
jstephens78 | 1:ebc0214989c0 | 116 | } |
jstephens78 | 1:ebc0214989c0 | 117 | } |
jstephens78 | 1:ebc0214989c0 | 118 | } |
jstephens78 | 1:ebc0214989c0 | 119 | float render_time = timer.read()*1000 - phys_time; |
jstephens78 | 1:ebc0214989c0 | 120 | |
jstephens78 | 1:ebc0214989c0 | 121 | printf("[%2.2f] Phys: %4.4f Render: %4.4f\r\n", |
jstephens78 | 1:ebc0214989c0 | 122 | dt, |
jstephens78 | 1:ebc0214989c0 | 123 | phys_time, |
jstephens78 | 1:ebc0214989c0 | 124 | render_time); |
jstephens78 | 1:ebc0214989c0 | 125 | } |
jstephens78 | 1:ebc0214989c0 | 126 | |
jstephens78 | 1:ebc0214989c0 | 127 | ClosePhysics(); // Unitialize physics |
jstephens78 | 1:ebc0214989c0 | 128 | } |
jstephens78 | 1:ebc0214989c0 | 129 | ``` |
jstephens78 | 1:ebc0214989c0 | 130 | |
jstephens78 | 1:ebc0214989c0 | 131 | ### Use in multi-file projects: |
jstephens78 | 1:ebc0214989c0 | 132 | **Note**: the `PHYSAC_IMPLEMENTATION` macro will cause the definitions of all |
jstephens78 | 1:ebc0214989c0 | 133 | the internal functions of Physac to be included. This should **only be done once, |
jstephens78 | 1:ebc0214989c0 | 134 | from .cpp file**. For example: |
jstephens78 | 1:ebc0214989c0 | 135 | ```c++ |
jstephens78 | 1:ebc0214989c0 | 136 | // myheader.h |
jstephens78 | 1:ebc0214989c0 | 137 | #define PHYSAC_NO_THREADS |
jstephens78 | 1:ebc0214989c0 | 138 | #define PHYSAC_STANDALONE |
jstephens78 | 1:ebc0214989c0 | 139 | #define _STDBOOL_H |
jstephens78 | 1:ebc0214989c0 | 140 | #include "physac.h" // this includes only the declarations |
jstephens78 | 1:ebc0214989c0 | 141 | |
jstephens78 | 1:ebc0214989c0 | 142 | ------ |
jstephens78 | 1:ebc0214989c0 | 143 | |
jstephens78 | 1:ebc0214989c0 | 144 | // myfile.cpp |
jstephens78 | 1:ebc0214989c0 | 145 | #include "myheader.h" |
jstephens78 | 1:ebc0214989c0 | 146 | |
jstephens78 | 1:ebc0214989c0 | 147 | #define PHYSAC_IMPLEMENTATION |
jstephens78 | 1:ebc0214989c0 | 148 | #include "physac.h" // this includes the definitions |
jstephens78 | 1:ebc0214989c0 | 149 | ``` |
jstephens78 | 1:ebc0214989c0 | 150 | |
jstephens78 | 1:ebc0214989c0 | 151 | ## Future work |
jstephens78 | 1:ebc0214989c0 | 152 | Possible future improvements to this port: |
jstephens78 | 1:ebc0214989c0 | 153 | |
jstephens78 | 1:ebc0214989c0 | 154 | 1. Re-work allocation scheme so users can pre-allocate arrays of bodies and |
jstephens78 | 1:ebc0214989c0 | 155 | manifolds |
jstephens78 | 1:ebc0214989c0 | 156 | |
jstephens78 | 1:ebc0214989c0 | 157 | 2. Implement a partial collision reporting scheme. |
jstephens78 | 1:ebc0214989c0 | 158 | |
jstephens78 | 1:ebc0214989c0 | 159 | Presently in `PhysicsStep()`, all bodies are iterated, a manifold is generated |
jstephens78 | 1:ebc0214989c0 | 160 | for every collision, and *then* manifolds are iteratively resolved. This is |
jstephens78 | 1:ebc0214989c0 | 161 | necessary for "correct" resolution of collisions in sequence with velocity, |
jstephens78 | 1:ebc0214989c0 | 162 | but this requires a lot of working memory. |
jstephens78 | 1:ebc0214989c0 | 163 | |
jstephens78 | 1:ebc0214989c0 | 164 | A possible trade-off would be to iterate bodies only until a certain number |
jstephens78 | 1:ebc0214989c0 | 165 | of manifolds are generated, then updating those bodies. This would reduce the |
jstephens78 | 1:ebc0214989c0 | 166 | resource demands for large scenes, at the expense of accuracy. |
jstephens78 | 1:ebc0214989c0 | 167 | |
jstephens78 | 1:ebc0214989c0 | 168 | |
jstephens78 | 0:e39efa4f4f58 | 169 | # Physac |
jstephens78 | 0:e39efa4f4f58 | 170 | |
jstephens78 | 0:e39efa4f4f58 | 171 | Physac is a small 2D physics engine written in pure C. The engine uses a fixed time-step thread loop to simluate physics. |
jstephens78 | 0:e39efa4f4f58 | 172 | A physics step contains the following phases: get collision information, apply dynamics, collision solving and position correction. It uses a very simple struct for physic bodies with a position vector to be used in any 3D rendering API. |
jstephens78 | 0:e39efa4f4f58 | 173 | |
jstephens78 | 0:e39efa4f4f58 | 174 | The header file includes some tweakable define values to fit the results that the user wants with a minimal bad results. Most of those values are commented with a little explanation about their uses. |
jstephens78 | 0:e39efa4f4f58 | 175 | |
jstephens78 | 0:e39efa4f4f58 | 176 | Physac API |
jstephens78 | 0:e39efa4f4f58 | 177 | ----- |
jstephens78 | 0:e39efa4f4f58 | 178 | |
jstephens78 | 0:e39efa4f4f58 | 179 | The PhysicsBody struct contains all dynamics information and collision shape. The user should use the following structure components: |
jstephens78 | 0:e39efa4f4f58 | 180 | ```c |
jstephens78 | 0:e39efa4f4f58 | 181 | typedef struct *PhysicsBody { |
jstephens78 | 0:e39efa4f4f58 | 182 | unsigned int id; |
jstephens78 | 0:e39efa4f4f58 | 183 | bool enabled; // Enabled dynamics state (collisions are calculated anyway) |
jstephens78 | 0:e39efa4f4f58 | 184 | Vector2 position; // Physics body shape pivot |
jstephens78 | 0:e39efa4f4f58 | 185 | Vector2 velocity; // Current linear velocity applied to position |
jstephens78 | 0:e39efa4f4f58 | 186 | Vector2 force; // Current linear force (reset to 0 every step) |
jstephens78 | 0:e39efa4f4f58 | 187 | float angularVelocity; // Current angular velocity applied to orient |
jstephens78 | 0:e39efa4f4f58 | 188 | float torque; // Current angular force (reset to 0 every step) |
jstephens78 | 0:e39efa4f4f58 | 189 | float orient; // Rotation in radians |
jstephens78 | 1:ebc0214989c0 | 190 | float staticFriction; // Friction when the body has no movement (0 to 1) |
jstephens78 | 0:e39efa4f4f58 | 191 | float dynamicFriction; // Friction when the body has movement (0 to 1) |
jstephens78 | 0:e39efa4f4f58 | 192 | float restitution; // Restitution coefficient of the body (0 to 1) |
jstephens78 | 0:e39efa4f4f58 | 193 | bool useGravity; // Apply gravity force to dynamics |
jstephens78 | 0:e39efa4f4f58 | 194 | bool isGrounded; // Physics grounded on other body state |
jstephens78 | 0:e39efa4f4f58 | 195 | bool freezeOrient; // Physics rotation constraint |
jstephens78 | 0:e39efa4f4f58 | 196 | PhysicsShape shape; // Physics body shape information (type, radius, vertices, normals) |
jstephens78 | 0:e39efa4f4f58 | 197 | } *PhysicsBody; |
jstephens78 | 0:e39efa4f4f58 | 198 | ``` |
jstephens78 | 1:ebc0214989c0 | 199 | |
jstephens78 | 0:e39efa4f4f58 | 200 | The header contains a few customizable define values. I set the values that gived me the best results. |
jstephens78 | 0:e39efa4f4f58 | 201 | ```c |
jstephens78 | 0:e39efa4f4f58 | 202 | #define PHYSAC_MAX_BODIES 64 |
jstephens78 | 0:e39efa4f4f58 | 203 | #define PHYSAC_MAX_MANIFOLDS 4096 |
jstephens78 | 0:e39efa4f4f58 | 204 | #define PHYSAC_MAX_VERTICES 24 |
jstephens78 | 0:e39efa4f4f58 | 205 | #define PHYSAC_CIRCLE_VERTICES 24 |
jstephens78 | 0:e39efa4f4f58 | 206 | |
jstephens78 | 0:e39efa4f4f58 | 207 | #define PHYSAC_COLLISION_ITERATIONS 100 |
jstephens78 | 0:e39efa4f4f58 | 208 | #define PHYSAC_PENETRATION_ALLOWANCE 0.05f |
jstephens78 | 0:e39efa4f4f58 | 209 | #define PHYSAC_PENETRATION_CORRECTION 0.4f |
jstephens78 | 0:e39efa4f4f58 | 210 | ``` |
jstephens78 | 0:e39efa4f4f58 | 211 | |
jstephens78 | 0:e39efa4f4f58 | 212 | Physac contains defines for memory management functions (malloc, free) to bring the user the opportunity to implement its own memory functions: |
jstephens78 | 0:e39efa4f4f58 | 213 | |
jstephens78 | 0:e39efa4f4f58 | 214 | ```c |
jstephens78 | 0:e39efa4f4f58 | 215 | #define PHYSAC_MALLOC(size) malloc(size) |
jstephens78 | 0:e39efa4f4f58 | 216 | #define PHYSAC_FREE(ptr) free(ptr) |
jstephens78 | 0:e39efa4f4f58 | 217 | ``` |
jstephens78 | 0:e39efa4f4f58 | 218 | |
jstephens78 | 0:e39efa4f4f58 | 219 | The Physac API functions availables for the user are the following: |
jstephens78 | 0:e39efa4f4f58 | 220 | |
jstephens78 | 0:e39efa4f4f58 | 221 | ```c |
jstephens78 | 0:e39efa4f4f58 | 222 | // Initializes physics values, pointers and creates physics loop thread |
jstephens78 | 0:e39efa4f4f58 | 223 | void InitPhysics(void); |
jstephens78 | 0:e39efa4f4f58 | 224 | |
jstephens78 | 0:e39efa4f4f58 | 225 | // Returns true if physics thread is currently enabled |
jstephens78 | 0:e39efa4f4f58 | 226 | bool IsPhysicsEnabled(void); |
jstephens78 | 0:e39efa4f4f58 | 227 | |
jstephens78 | 0:e39efa4f4f58 | 228 | // Sets physics global gravity force |
jstephens78 | 0:e39efa4f4f58 | 229 | void SetPhysicsGravity(float x, float y); |
jstephens78 | 0:e39efa4f4f58 | 230 | |
jstephens78 | 0:e39efa4f4f58 | 231 | // Creates a new circle physics body with generic parameters |
jstephens78 | 0:e39efa4f4f58 | 232 | PhysicsBody CreatePhysicsBodyCircle(Vector2 pos, float radius, float density); |
jstephens78 | 0:e39efa4f4f58 | 233 | |
jstephens78 | 0:e39efa4f4f58 | 234 | // Creates a new rectangle physics body with generic parameters |
jstephens78 | 0:e39efa4f4f58 | 235 | PhysicsBody CreatePhysicsBodyRectangle(Vector2 pos, float width, float height, float density); |
jstephens78 | 0:e39efa4f4f58 | 236 | |
jstephens78 | 0:e39efa4f4f58 | 237 | // Creates a new polygon physics body with generic parameters |
jstephens78 | 0:e39efa4f4f58 | 238 | PhysicsBody CreatePhysicsBodyPolygon(Vector2 pos, float radius, int sides, float density); |
jstephens78 | 0:e39efa4f4f58 | 239 | |
jstephens78 | 0:e39efa4f4f58 | 240 | // Adds a force to a physics body |
jstephens78 | 0:e39efa4f4f58 | 241 | void PhysicsAddForce(PhysicsBody body, Vector2 force); |
jstephens78 | 0:e39efa4f4f58 | 242 | |
jstephens78 | 0:e39efa4f4f58 | 243 | // Adds a angular force to a physics body |
jstephens78 | 0:e39efa4f4f58 | 244 | void PhysicsAddTorque(PhysicsBody body, float amount); |
jstephens78 | 0:e39efa4f4f58 | 245 | |
jstephens78 | 0:e39efa4f4f58 | 246 | // Shatters a polygon shape physics body to little physics bodies with explosion force |
jstephens78 | 0:e39efa4f4f58 | 247 | void PhysicsShatter(PhysicsBody body, Vector2 position, float force); |
jstephens78 | 0:e39efa4f4f58 | 248 | |
jstephens78 | 0:e39efa4f4f58 | 249 | // Returns the current amount of created physics bodies |
jstephens78 | 0:e39efa4f4f58 | 250 | int GetPhysicsBodiesCount(void); |
jstephens78 | 0:e39efa4f4f58 | 251 | |
jstephens78 | 0:e39efa4f4f58 | 252 | // Returns a physics body of the bodies pool at a specific index |
jstephens78 | 0:e39efa4f4f58 | 253 | PhysicsBody GetPhysicsBody(int index); |
jstephens78 | 0:e39efa4f4f58 | 254 | |
jstephens78 | 0:e39efa4f4f58 | 255 | // Returns the physics body shape type (PHYSICS_CIRCLE or PHYSICS_POLYGON) |
jstephens78 | 0:e39efa4f4f58 | 256 | int GetPhysicsShapeType(int index); |
jstephens78 | 0:e39efa4f4f58 | 257 | |
jstephens78 | 0:e39efa4f4f58 | 258 | // Returns the amount of vertices of a physics body shape |
jstephens78 | 0:e39efa4f4f58 | 259 | int GetPhysicsShapeVerticesCount(int index); |
jstephens78 | 0:e39efa4f4f58 | 260 | |
jstephens78 | 0:e39efa4f4f58 | 261 | // Returns transformed position of a body shape (body position + vertex transformed position) |
jstephens78 | 0:e39efa4f4f58 | 262 | Vector2 GetPhysicsShapeVertex(PhysicsBody body, int vertex); |
jstephens78 | 0:e39efa4f4f58 | 263 | |
jstephens78 | 0:e39efa4f4f58 | 264 | // Sets physics body shape transform based on radians parameter |
jstephens78 | 0:e39efa4f4f58 | 265 | void SetPhysicsBodyRotation(PhysicsBody body, float radians); |
jstephens78 | 0:e39efa4f4f58 | 266 | |
jstephens78 | 0:e39efa4f4f58 | 267 | // Unitializes and destroy a physics body |
jstephens78 | 0:e39efa4f4f58 | 268 | void DestroyPhysicsBody(PhysicsBody body); |
jstephens78 | 0:e39efa4f4f58 | 269 | |
jstephens78 | 0:e39efa4f4f58 | 270 | // Unitializes physics pointers and closes physics loop thread |
jstephens78 | 0:e39efa4f4f58 | 271 | void ClosePhysics(void); |
jstephens78 | 0:e39efa4f4f58 | 272 | ``` |
jstephens78 | 0:e39efa4f4f58 | 273 | _Note: InitPhysics() needs to be called at program start and ClosePhysics() before the program ends. Closing and initializing Physac during the program flow doesn't affect or produces any error (useful as a 'reset' to destroy any created body by user in runtime)._ |
jstephens78 | 0:e39efa4f4f58 | 274 | |
jstephens78 | 0:e39efa4f4f58 | 275 | Dependencies |
jstephens78 | 0:e39efa4f4f58 | 276 | ----- |
jstephens78 | 0:e39efa4f4f58 | 277 | |
jstephens78 | 0:e39efa4f4f58 | 278 | Physac uses the following C libraries for memory management, math operations and some debug features: |
jstephens78 | 0:e39efa4f4f58 | 279 | |
jstephens78 | 0:e39efa4f4f58 | 280 | * stdlib.h - Memory allocation [malloc(), free(), srand(), rand()]. |
jstephens78 | 0:e39efa4f4f58 | 281 | * stdio.h - Message logging (only if PHYSAC_DEBUG is defined) [printf()]. |
jstephens78 | 1:ebc0214989c0 | 282 | * math.h - Math operations functions [cos(), sin(), fabs(), sqrtf()]. |