XProger

macro CANVAS_SET_ALPHA col {	; prepare mmx registers (alpha) by col (0xAAxxxxxx)
	push	col
	shr	col, 24
	pxor	mm5, mm5
	movd	mm7, col
	pshufw	mm7, mm7, 0
	neg	col
	add	col, 256
	movd	mm6, col
	pshufw	mm6, mm6, 0

XProger

b = 1 << i;
x = (0x287A & b) != 0
y = (0x02AF & b) != 0
z = (0x31E3 & b) != 0

XProger

vec3 cuteSort(vec3 n) {
  float a = min(min(n.x, n.y), n.z);
  float b = max(max(n.x, n.y), n.z);
  return vec3(a, n.x + n.y + n.z - a - b, b);
}

XProger

void getBasis(const vec3 &n, vec3 &t, vec3 &b) {
    if (n.z < -0.9999999f) {
        t = vec3( 0.0f, -1.0f, 0.0f);
        b = vec3(-1.0f,  0.0f, 0.0f);
        return;
    }
    const float x = 1.0f / (1.0f + n.z);
    const float y = -n.x*n.y*x;
    t = vec3(1.0f - n.x*n.x*x, y, -n.x);
    b = vec3(b, 1.0f - n.y*n.y*x, -n.y);

XProger

// Computes signed distance between a point and a plane
// vPlane: Contains plane coefficients (a,b,c,d) where: ax + by + cz = d
// vPoint: Point to be tested against the plane.
float DistanceToPlane( vec4 vPlane, vec3 vPoint )
{
    return dot(vec4(vPoint, 1.0), vPlane);
}
 
// Frustum cullling on a sphere. Returns > 0 if visible, <= 0 otherwise
float CullSphere( vec4 vPlanes[6], vec3 vCenter, float fRadius )

XProger

vec4 dx = vec4(0.25, 0.96, -0.25, -0.96) * uTexelSize.xyxy + vTexCoord.xyxy;
vec4 dy = vec4(0.25, 0.96, -0.25, -0.96) * uTexelSize.yxyx + vTexCoord.yxyx;

vec4 average = (texture2D(sTex, dx.zy) + texture2D(sTex, dx.xw) +
                texture2D(sTex, dy.yx) + texture2D(sTex, dy.wz)) * 0.25;

XProger

bool AABB::intersect(const vec3 &rayPos, const vec3 &rayDir, float &t) const {
    float t1 = INF, t0 = -t1;
    for (int i = 0; i < 3; i++)
        if (rayDir[i] != 0) {
            float lo = (min[i] - rayPos[i]) / rayDir[i];
            float hi = (max[i] - rayPos[i]) / rayDir[i];
            t0 = _max(t0, _min(lo, hi));
            t1 = _min(t1, _max(lo, hi));
        } else
            if (rayPos[i] < min[i] || rayPos[i] > max[i])

XProger

// quat
const quat quat::IDENTITY(0.0f, 0.0f, 0.0f, 1.0f);
const quat quat::ZERO(0.0f, 0.0f, 0.0f, 0.0f);

quat::quat() {}
quat::quat(float x, float y, float z, float w) : x(x), y(y), z(z), w(w) {}

quat::quat(const vec3 &axis, float angle) {
	angle *= 0.5f;
	float s = sinf(angle);

XProger

bool Circle::intersect(const Segment2D &segment, vec2 &n, float &t) const {
	vec2 ap = center - segment.a;
	vec2 ab = segment.b - segment.a;

	float dab = ab.dot(ab);
	if (dab == 0.0f) return false;

	t = clamp(ap.dot(ab) / dab, 0.0f, 1.0f);
	n = center - (segment.a + ab * t);
	t = n.length2();

XProger

#include <stdio.h>
#include <math.h>
#include <windows.h>
#include <gl/GL.h>

// simulation
#define SIZE_X 129
#define SIZE_Y 129
#define RIGID_FACTOR   0.5f
#define DAMPING_FACTOR 0.998f