Comment détecter la zone (circulaire) d'une touche sur les iBidules ? Il faut obtenir un UITouch depuis un UIEvent et à partir de là :
float vf = 10.0;
id valFloat = [thisTouch valueForKey:"pathMajorRadius"];
if (valFloat != nil) { vf = [valFloat floatValue]; }Source : http://stackoverflow.com/questions/5179426/tap-pressure-strength-detection-using-accelerometer
- (void)display {
if ([self.delegate respondsToSelector:@selector(displayLayer:)]) {
[[self.delegate retain] displayLayer:self];
[self.delegate release];
return;
}
CABackingStoreRef backing = _backingStore;
if (!backing) {
backing = _backingStore = ... code here to create and configure
the CABackingStore properly, given the layer size, isOpaque,
contentScale, etc.
}
CGContextRef gc = ... code here to create a CGContext that draws into backing,
with the proper clip region
... also code to set up a bitmap in memory shared with the WindowServer process
[self drawInContext:gc];
self.contents = backing;
}
- (void)drawInContext:(CGContextRef)gc {
if ([self.delegate respondsToSelector:@selector(drawLayer:inContext:)]) {
[[self.delegate retain] drawLayer:self inContext:gc];
[self.delegate release];
return;
} else {
CAAction *action = [self actionForKey:@"onDraw"];
if (action) {
NSDictionary *args = [NSDictionary dictionaryWithObject:gc forKey:@"context"];
[action runActionForKey:@"onDraw" object:self arguments:args];
}
}
}
- (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)gc {
set gc's stroke and fill color spaces to device RGB;
UIGraphicsPushContext(gc);
fill gc with the view's background color;
if ([self respondsToSelector:@selector(drawRect:)]) {
[self drawRect:CGContextGetClipBoundingBox(gc)];
}
UIGraphicsPopContext(gc);
}
$("#canvas3D")[0].getContext("webgl", {antialias:true, depth:true, stencil:true})Il y a tout un paquet de types dérivés de l'interface WebGLObject.
| Objet | Création | Utilisation | Destruction |
| WebGLBuffer | glGenBuffers | glBindBuffer | glDeleteBuffers |
| WebGLFrameBuffer | glGenFramebuffers | glBindFramebuffer | glDeleteFramebuffers |
| WebGLProgram | glCreateProgram | glUseProgram | glDeleteProgram |
| WebGLRenderbuffer | glGenRenderbuffers | glBindRenderbuffer | glDeleteRenderbuffers |
| WebGLShader | glCreateShader | glAttachShader | glDeleteShader |
| WebGLTexture | glGenTextures | glBindTexture | glDeleteTextures |
| WebGLUniformLocation |
Il faut bien démarrer quelque part et c'est ici ! C'est sûr que c'est pas terrible, beaucoup de code pour un résultat bien consternant, mais je jette mes bases. Je dois reprendre ce qui était naturel il y a quelques années...
#include <stdio.h>
#include <stdlib.h>
#include <X11/Xlib.h>
#include <GL/glx.h>
#include <GL/gl.h>
static int snglBuf[] = {GLX_RGBA, GLX_RED_SIZE, 1, GLX_GREEN_SIZE, 1, GLX_BLUE_SIZE, 1, GLX_DEPTH_SIZE, 12, None};
static int dblBuf[] = {GLX_RGBA, GLX_RED_SIZE, 1, GLX_GREEN_SIZE, 1, GLX_BLUE_SIZE, 1, GLX_DEPTH_SIZE, 12, GLX_DOUBLEBUFFER, None};
Display* Dpy;
Window Win;
Bool DoubleBuffer = True;
GLfloat XAngle = 42.0, YAngle = 82.0, ZAngle = 112.0;
int FatalError(int errorCode, char* str)
{
printf("%s\n", str);
return errorCode;
}
void redraw()
{
static Bool DisplayListInited = False;
if (DisplayListInited) {
glCallList(1);
} else {
glNewList(1, GL_COMPILE_AND_EXECUTE);
//
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glBegin(GL_QUADS);
glColor3f(0.0, 0.7, 0.1); //Green
glVertex3f(-1.0, 1.0, 1.0);
glVertex3f(1.0, 1.0, 1.0);
glVertex3f(1.0, -1.0, 1.0);
glVertex3f(-1.0, -1.0, 1.0);
glColor3f(0.9, 1.0, 0.0); //Yellow
glVertex3f(-1.0, 1.0, -1.0);
glVertex3f(1.0, 1.0, -1.0);
glVertex3f(1.0, -1.0, -1.0);
glVertex3f(-1.0, -1.0, -1.0);
glColor3f(0.2, 0.2, 1.0); //Blue
glVertex3f(-1.0, 1.0, 1.0);
glVertex3f(1.0, 1.0, 1.0);
glVertex3f(1.0, 1.0, -1.0);
glVertex3f(-1.0, 1.0, -1.0);
glColor3f(0.7, 0.0, 0.1); //Red
glVertex3f(-1.0, -1.0, 1.0);
glVertex3f(1.0, -1.0, 1.0);
glVertex3f(1.0, -1.0, -1.0);
glVertex3f(-1.0, -1.0, -1.0);
glEnd();
//
glEndList();
DisplayListInited = True;
}
//On affiche réellement quelque chose...
if (DoubleBuffer) glXSwapBuffers(Dpy, Win);
else glFlush();
}
int main(int argc, char** argv)
{
XVisualInfo* vi;
Colormap CMap;
XSetWindowAttributes swa;
GLXContext cx;
XEvent Event;
Bool NeedRedraw = False, RecalcModelView = True;
int Dummy;
//
Dpy = XOpenDisplay(NULL);
if (!Dpy) return FatalError(1, "Couldn't open display...");
if (!glXQueryExtension(Dpy, &Dummy, &Dummy)) return FatalError(2, "X n'a pas d'extension OpenGL.");
//
vi = glXChooseVisual(Dpy, DefaultScreen(Dpy), dblBuf);
if (!vi) {
vi = glXChooseVisual(Dpy, DefaultScreen(Dpy), snglBuf);
if (!vi) return FatalError(3, "Pas de visuel RGB avec buffer de profondeur.");
DoubleBuffer = False;
}
printf("DoubleBuffer : %d\n", DoubleBuffer);
if (vi->class != TrueColor) return FatalError(4, "J'ai besoin d'un visuel en true color !");
//
cx = glXCreateContext(Dpy, vi, None, True);
if (!cx) return FatalError(5, "Impossible de créer le contexte de rendu.");
//
CMap = XCreateColormap(Dpy, RootWindow(Dpy, vi->screen), vi->visual, AllocNone);
swa.colormap = CMap;
swa.border_pixel = 0;
swa.event_mask = ExposureMask | ButtonPressMask | StructureNotifyMask;
Win = XCreateWindow(Dpy, RootWindow(Dpy, vi->screen), 0, 0, 300, 300, 0, vi->depth, InputOutput, vi->visual, CWBorderPixel|CWColormap|CWEventMask, &swa);
XSetStandardProperties(Dpy, Win, "glxsimple", "glxsimple", None, argv, argc, NULL);
//
glXMakeCurrent(Dpy, Win, cx);
XMapWindow(Dpy, Win);
//
glEnable(GL_DEPTH_TEST);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-1.0, 1.0, -1.0, 1.0, 1.0, 10.0);
//
while (True) {
do {
XNextEvent(Dpy, &Event);
switch (Event.type) {
case ButtonPress:
RecalcModelView = True;
switch(Event.xbutton.button) {
case 1: XAngle += 10.0; break;
case 2: YAngle += 10.0; break;
case 3: ZAngle += 10.0; break;
}
break;
case ConfigureNotify:
glViewport(0, 0, Event.xconfigure.width, Event.xconfigure.height);
case Expose:
NeedRedraw = True;
break;
}
} while(XPending(Dpy));
//
if (RecalcModelView) {
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0.0, -3.0);
glRotatef(XAngle, 0.1, 0.0, 0.0);
glRotatef(YAngle, 0.0, 0.1, 0.0);
glRotatef(ZAngle, 0.0, 0.0, 1.0);
//
RecalcModelView = False;
NeedRedraw = True;
}
if (NeedRedraw) {
redraw();
NeedRedraw = False;
}
}
//
return 0;
}
Pour compiler ça, si on suppose que le code est sauvé dans un fichier simplegl.c, on lance :
gcc -o simplegl -lGL -lX11 simplegl.c
Le résulat du gloubi-boulga ci-dessus ? Et bien voilà, bow you sucker !
Une classe qui utilise dlopen (équivalent de LoadLibrary sous Win32) pour ne pas avoir à lier libmysqlclient à un programme. Comme dans n'importe quel wrapper : il n'y a rien ici de bien compliqué ou de bien intéressant. C'est juste un bout de code utile pour se simplifier la vie.
#include "dlfcn.h"
#include <mysql.h>
class MySQL
{
public:
MySQL()
{
handle = NULL;
LibHandle = dlopen("/usr/local/mysql/lib/mysql/libmysqlclient.so", RTLD_LAZY);
//Tous les dlsym dont on a besoin
MySQL_Init = (MYSQL* (*)(MYSQL*))dlsym(LibHandle, "mysql_init");
MySQL_Close = (void (*)(MYSQL*))dlsym(LibHandle, "mysql_close");
MySQL_Real_Connect = (MYSQL* (*)(MYSQL *, const char *, const char *, const char *, const char *, unsigned int, const char *, unsigned long))dlsym(LibHandle, "mysql_real_connect");
MySQL_Error = (const char*(*)(MYSQL*)) dlsym(LibHandle, "mysql_error");
MySQL_Real_Query = (int (*)(MYSQL *, const char *, unsigned long)) dlsym(LibHandle, "mysql_real_query");
MySQL_Use_Result = (MYSQL_RES* (*)(MYSQL*)) dlsym(LibHandle, "mysql_use_result");
MySQL_Store_Result = (MYSQL_RES* (*)(MYSQL*)) dlsym(LibHandle, "mysql_store_result");
MySQL_Fetch_Row = (MYSQL_ROW (*)(MYSQL_RES *)) dlsym(LibHandle, "mysql_fetch_row");
MySQL_Free_Result = (void (*)(MYSQL_RES*))dlsym(LibHandle, "mysql_free_result");
MySQL_End_Library = (void (*)())dlsym(LibHandle, "mysql_library_end");
MySQL_Server_Init = (void (*)())dlsym(LibHandle, "mysql_server_init");
MySQL_Server_End = (void (*)())dlsym(LibHandle, "mysql_server_end");
}
~MySQL()
{
MySQL_Close(handle);
MySQL_Server_End();
dlclose(LibHandle);
}
bool init()
{
handle = MySQL_Init(NULL);
return handle != NULL;
}
void serverInit() { MySQL_Server_Init(); }
bool connect(char* dbName, char* userName, char* passwd)
{
MYSQL* Handle = MySQL_Real_Connect(handle, NULL, userName, passwd, dbName, 0, NULL, 0);
return Handle == handle;
}
bool query(const char* query)
{
bool Ret = MySQL_Real_Query(handle, query, strlen(query)) == 0;
if (!Ret) return false;
rows = MySQL_Store_Result(handle);
return rows != NULL;
}
bool freeResult() { MySQL_Free_Result(rows); }
bool fetchRow(MYSQL_ROW& row)
{
row = MySQL_Fetch_Row(rows);
return !(row == NULL);
}
protected:
void* LibHandle;
MYSQL* handle;
MYSQL_RES* rows;
//Les pointeurs vers les fonctions de la lib MySQL
MYSQL* (*MySQL_Init)(MYSQL*);
void (*MySQL_Close)(MYSQL*);
MYSQL* (*MySQL_Real_Connect)(MYSQL *, const char *, const char *, const char *, const char *, unsigned int , const char *, unsigned long );
const char* (*MySQL_Error)(MYSQL*);
int (*MySQL_Real_Query)(MYSQL *, const char *, unsigned long);
MYSQL_RES* (*MySQL_Store_Result)(MYSQL*);
MYSQL_RES* (*MySQL_Use_Result)(MYSQL*);
MYSQL_ROW (*MySQL_Fetch_Row)(MYSQL_RES *);
void (*MySQL_Free_Result)(MYSQL_RES*);
void (*MySQL_End_Library)();
void (*MySQL_Server_Init)();
void (*MySQL_Server_End)();
};