Add water demo

TODO.txt

@@ -13,15 +13,15 @@ TODO:
 - bounding box/sphere test functions/macros for optimization of environment
   building, plus a demo that tests if it actually accelerates it
 - test ray casting (e.g. the hit of an outside ray should always be outside)
-- ray casting against bodies
 - check if using fastBSphere vs normal BSphere doesn't affect the simulation
   result (it shouldn't)
-- world state hash? for testing determinism etc.
 - fine tune the number of reshapes needed for nice behavior
 - bug? bodies stuck inside each other resist falling down by gravity (stack.c)
 
 DONE:
 - demo: car
+- ray casting against bodies
+- world state hash? for testing determinism etc.
 - body being pushed (e.g. by gravity) onto a sharp edge will likely not resist
   (due to only linear forces in connections) and will very easily be split very
   wide -- TRY AND FIX! Fix could be e.g. in a special function that checks

programs/make.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
 
-PROGRAM=car # change this to name of a program you want to compile :)
+PROGRAM=water # change this to name of a program you want to compile :)
 
 clear; clear; g++ -x c -g -fmax-errors=5 -pedantic -O3 -Wall -Wextra -Wstrict-prototypes -Wold-style-definition -Wno-unused-parameter -Wno-missing-field-initializers -o $PROGRAM $PROGRAM.c -lm -lSDL2 && ./$PROGRAM

programs/water.c

@@ -0,0 +1,170 @@
+#define CAMERA_STEP 200
+
+#include "helper.h"
+
+#define GRID_RESOLUTION 8
+#define GRID_STEP 1000
+#define JOINT_SIZE 300
+#define BALL_SIZE 700
+
+#define ROOM_SIZE (GRID_RESOLUTION * GRID_STEP + JOINT_SIZE)
+
+TPE_Vec3 environmentDistance(TPE_Vec3 p, TPE_Unit maxD)
+{
+  return TPE_envAABoxInside(p,TPE_vec3(0,0,0),TPE_vec3(ROOM_SIZE,ROOM_SIZE,ROOM_SIZE));
+}
+
+#define WATER_JOINTS (GRID_RESOLUTION * GRID_RESOLUTION)
+#define WATER_CONNECTIONS (2 * ((GRID_RESOLUTION - 1) * GRID_RESOLUTION))
+
+TPE_Joint joints[WATER_JOINTS + 1];
+TPE_Connection connections[WATER_CONNECTIONS];
+
+S3L_Unit vertices[WATER_JOINTS * 3];
+S3L_Index triangles[((GRID_RESOLUTION - 1) * (GRID_RESOLUTION - 1) * 2) * 3];
+S3L_Model3D model;
+
+TPE_Body bodies[2];
+
+TPE_Vec3 jointPlace(int index)
+{
+  return TPE_vec3((-1 * GRID_RESOLUTION * GRID_STEP) / 2 + (index % GRID_RESOLUTION) * GRID_STEP + GRID_STEP / 2,0,
+    (-1 * GRID_RESOLUTION * GRID_STEP) / 2 + (index / GRID_RESOLUTION) * GRID_STEP + GRID_STEP / 2);
+}
+
+int main(void)
+{
+  helper_init();
+
+  puts("WSAD, XC: move the ball");
+
+  helper_debugDrawOn = 1;
+
+  s3l_scene.camera.transform.translation.z = -3000;
+  s3l_scene.camera.transform.translation.y = 2000;
+  s3l_scene.camera.transform.translation.x = 0;
+  s3l_scene.camera.transform.rotation.y = TPE_FRACTIONS_PER_UNIT / 16;
+
+  // build the grid:
+
+  int index = 0;
+
+  for (int j = 0; j < GRID_RESOLUTION; ++j)
+    for (int i = 0; i < GRID_RESOLUTION; ++i)
+    {
+      joints[j * GRID_RESOLUTION + i] = TPE_joint(jointPlace(index),JOINT_SIZE);
+      index++;
+    }
+
+  index = 0;
+
+  for (int j = 0; j < GRID_RESOLUTION; ++j)
+    for (int i = 0; i < GRID_RESOLUTION - 1; ++i)
+    {
+      connections[index].joint1 = j * GRID_RESOLUTION + i;
+      connections[index].joint2 = connections[index].joint1 + 1;
+
+      index++;
+
+      connections[index].joint1 = i * GRID_RESOLUTION + j;
+      connections[index].joint2 = connections[index].joint1 + GRID_RESOLUTION;
+
+      index++;
+    }
+
+index = 0;
+
+for (int j = 0; j < GRID_RESOLUTION - 1; ++j)
+  for (int i = 0; i < GRID_RESOLUTION - 1; ++i)
+  {
+triangles[index] = j * GRID_RESOLUTION + i;
+triangles[index + 1] = triangles[index] + 1;
+triangles[index + 2] = triangles[index + 1] + GRID_RESOLUTION;
+
+triangles[index + 3] = triangles[index];
+triangles[index + 4] = triangles[index + 1] + GRID_RESOLUTION;
+triangles[index + 5] = triangles[index] + GRID_RESOLUTION;
+
+index += 6;
+  }
+
+S3L_model3DInit(
+  vertices,
+  WATER_JOINTS * 3,
+  triangles,
+  ((GRID_RESOLUTION - 1) * (GRID_RESOLUTION - 1) * 2),
+  &model);
+
+
+  TPE_bodyInit(&bodies[0],joints,WATER_JOINTS,connections,WATER_CONNECTIONS,
+    1000);
+
+  bodies[0].flags |= TPE_BODY_FLAG_SOFT;
+
+  joints[WATER_JOINTS] = TPE_joint(TPE_vec3(0,0,ROOM_SIZE / 4),BALL_SIZE);
+
+  TPE_bodyInit(&bodies[1],joints + WATER_JOINTS,1,connections,0,200);
+
+  TPE_worldInit(&tpe_world,bodies,2,environmentDistance);
+
+  while (helper_running)
+  {
+    helper_frameStart();
+
+    helper_cameraFreeMovement();
+
+TPE_bodyActivate(&bodies[0]);
+TPE_bodyActivate(&bodies[1]);
+
+S3L_Unit *v = vertices;
+
+for (int i = 0; i < WATER_JOINTS; ++i)
+{
+  *v = joints[i].position.x;
+  v++;
+  *v = joints[i].position.y;
+  v++;
+  *v = joints[i].position.z;
+  v++;
+}
+
+for (int index = 0; index < WATER_JOINTS; ++index)
+  if (index % GRID_RESOLUTION == 0 || index % GRID_RESOLUTION == GRID_RESOLUTION - 1 ||
+      index / GRID_RESOLUTION == 0 || index / GRID_RESOLUTION == GRID_RESOLUTION - 1)
+    TPE_jointPin(&joints[index],jointPlace(index));
+
+    TPE_worldStep(&tpe_world);
+
+    TPE_bodyApplyGravity(&tpe_world.bodies[1], bodies[1].joints[0].position.y > 0 ? 5 : -10);
+
+    #define ACC 25
+    if (sdl_keyboard[SDL_SCANCODE_W])
+      TPE_bodyAccelerate(&bodies[1],TPE_vec3(0,0,ACC));
+    else if (sdl_keyboard[SDL_SCANCODE_S])
+      TPE_bodyAccelerate(&bodies[1],TPE_vec3(0,0,-1 * ACC));
+    else if (sdl_keyboard[SDL_SCANCODE_D])
+      TPE_bodyAccelerate(&bodies[1],TPE_vec3(ACC,0,0));
+    else if (sdl_keyboard[SDL_SCANCODE_A])
+      TPE_bodyAccelerate(&bodies[1],TPE_vec3(-1 * ACC,0,0));
+    else if (sdl_keyboard[SDL_SCANCODE_C])
+      TPE_bodyAccelerate(&bodies[1],TPE_vec3(0,ACC,0));
+    else if (sdl_keyboard[SDL_SCANCODE_X])
+      TPE_bodyAccelerate(&bodies[1],TPE_vec3(0,-1 * ACC,0));
+
+helper_set3dColor(255,0,0);
+
+helper_draw3dSphere(bodies[1].joints[0].position,TPE_vec3(BALL_SIZE,BALL_SIZE,BALL_SIZE),TPE_vec3(0,0,0));
+
+helper_set3dColor(0,100,255);
+helper_drawModel(&model,TPE_vec3(0,0,0),TPE_vec3(512,512,512),TPE_vec3(0,0,0));
+
+    if (helper_debugDrawOn)
+      helper_debugDraw(1);
+
+    helper_frameEnd();
+  }
+
+  helper_end();
+
+  return 0;
+}