+void update_monitor_vertices(CompositedScreen *screen, CompositedMonitor *monitor)
+{
+ unsigned t;
+ unsigned data_size;
+ float *vertex_data;
+ unsigned short *index_data;
+ unsigned x, y;
+ unsigned i;
+ float aspect;
+ float cyl_w_sq;
+ float sin_ksv;
+ float cos_ksv;
+
+ t = monitor->tessellation;
+
+ data_size = (t+1)*(t+1)*4*sizeof(float);
+ vertex_data = (float *)malloc(data_size);
+ aspect = (float)monitor->width/monitor->height;
+ cyl_w_sq = 0.25f-(0.5f-monitor->cylinder_depth)*(0.5f-monitor->cylinder_depth);
+ sin_ksv = monitor->keystone_vertical/sqrt(1.0f+monitor->keystone_vertical*monitor->keystone_vertical);
+ cos_ksv = sqrt(1.0f-sin_ksv*sin_ksv);
+ for(y=0; y<=t; ++y)
+ for(x=0; x<=t; ++x)
+ {
+ float xf, yf, z, rz;
+ float scale;
+ float *v;
+
+ xf = (float)x/t;
+ yf = (float)y/t;
+
+ v = vertex_data+(y*(t+1)+x)*4;
+ v[2] = (monitor->x+xf*monitor->width)/screen->width;
+ v[3] = (monitor->y+yf*monitor->height)/screen->height;
+
+ z = sqrt(0.25f-(xf-0.5f)*(xf-0.5f)*4.0f*cyl_w_sq)-0.5f+monitor->cylinder_depth;
+ if(monitor->keystone_vertical>0)
+ {
+ rz = (1.0f-yf)/aspect*sin_ksv+z*cos_ksv;
+ yf = 1.0f-((1.0f-yf)*cos_ksv-z*aspect*sin_ksv);
+ z = rz;
+ }
+ else if(monitor->keystone_vertical<0)
+ {
+ rz = z*cos_ksv-yf/aspect*sin_ksv;
+ yf = yf*cos_ksv+z*aspect*sin_ksv;
+ z = rz;
+ }
+ scale = monitor->perspective/(monitor->perspective+z);
+ v[0] = 0.5f+(xf-0.5f)*scale;
+ v[1] = monitor->vertical_center+(yf-monitor->vertical_center)*scale;
+ }
+ glBindBuffer(GL_ARRAY_BUFFER, monitor->vertex_buffer);
+ glBufferData(GL_ARRAY_BUFFER, data_size, vertex_data, GL_STATIC_DRAW);
+ glBindBuffer(GL_ARRAY_BUFFER, 0);
+ free(vertex_data);
+
+ monitor->nelements = t*((t+1)*2+1)-1;
+ data_size = monitor->nelements*sizeof(unsigned short);
+ index_data = (unsigned short *)malloc(data_size);
+ i = 0;
+ for(y=0; y<t; ++y)
+ {
+ if(y>0)
+ index_data[i++] = 0xFFFF;
+ for(x=0; x<=t; ++x)
+ {
+ index_data[i++] = (y+1)*(t+1)+x;
+ index_data[i++] = y*(t+1)+x;
+ }
+ }
+ glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, monitor->index_buffer);
+ glBufferData(GL_ELEMENT_ARRAY_BUFFER, data_size, index_data, GL_STATIC_DRAW);
+ glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+ free(index_data);
+}
+
+int initialize_monitor(Compositor *compositor, CompositedScreen *screen, XRRScreenResources *xrr_res, unsigned index)
+{
+ CompositedMonitor *monitor;
+ XRROutputInfo *output;
+ int namelen;
+ XRRCrtcInfo *crtc;
+ unsigned buffers[2];
+ unsigned stride;
+
+ monitor = &screen->monitors[index];
+
+ output = XRRGetOutputInfo(compositor->display, xrr_res, xrr_res->outputs[index]);
+ namelen = strlen(output->name);
+ monitor->name = (char *)malloc(namelen+1);
+ strcpy(monitor->name, output->name);
+ monitor->enabled = !!output->crtc;
+ if(!monitor->enabled)
+ {
+ XRRFreeOutputInfo(output);
+ return 1;
+ }
+
+ crtc = XRRGetCrtcInfo(compositor->display, xrr_res, output->crtc);
+ monitor->x = crtc->x;
+ monitor->y = crtc->y;
+ monitor->width = crtc->width;
+ monitor->height = crtc->height;
+ XRRFreeCrtcInfo(crtc);
+ XRRFreeOutputInfo(output);
+
+ monitor->keystone_vertical = 0.0f;
+ monitor->cylinder_depth = 0.0f;
+ monitor->vertical_center = 0.5f;
+ monitor->perspective = 1.0f;
+
+ glGenBuffers(2, buffers);
+ monitor->vertex_buffer = buffers[0];
+ monitor->index_buffer = buffers[1];
+
+ monitor->tessellation = 50;
+ update_monitor_vertices(screen, monitor);
+ stride = 4*sizeof(float);
+
+ glGenVertexArrays(1, &monitor->vertex_array);
+ glBindVertexArray(monitor->vertex_array);
+ glBindBuffer(GL_ARRAY_BUFFER, monitor->vertex_buffer);
+ glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, stride, NULL);
+ glEnableVertexAttribArray(0);
+ glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, stride, (void *)(2*sizeof(float)));
+ glEnableVertexAttribArray(1);
+ glBindBuffer(GL_ARRAY_BUFFER, 0);
+ glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, monitor->index_buffer);
+ glBindVertexArray(0);
+
+ return 1;
+}
+
+CompositedMonitor *find_monitor_by_name(CompositedScreen *screen, char *name)
+{
+ unsigned i;
+
+ for(i=0; i<screen->nmonitors; ++i)
+ if(!strcmp(screen->monitors[i].name, name))
+ return &screen->monitors[i];
+
+ return NULL;
+}
+
+void update_geometry_correction(Compositor *compositor, CompositedScreen *screen)
+{
+ Atom prop_type;
+ int prop_format;
+ unsigned long overflow;
+ unsigned long names_length;
+ char *names;
+ unsigned long values_length;
+ short *values;
+ char *name_ptr;
+ unsigned i;
+
+ XGetWindowProperty(compositor->display, screen->root, compositor->monitors_atom, 0, 64, False, XA_STRING,
+ &prop_type, &prop_format, &names_length, &overflow, (unsigned char **)&names);
+ if(prop_type!=XA_STRING || prop_format!=8)
+ return;
+
+ XGetWindowProperty(compositor->display, screen->root, compositor->correction_atom, 0, 64, False, XA_INTEGER,
+ &prop_type, &prop_format, &values_length, &overflow, (unsigned char **)&values);
+ if(prop_type!=XA_INTEGER || prop_format!=16)
+ {
+ XFree(names);
+ return;
+ }
+
+ use_gl(compositor, screen);
+
+ name_ptr = names;
+ for(i=0; i*4<values_length; ++i)
+ {
+ CompositedMonitor *monitor;
+
+ if(name_ptr>=names+names_length)
+ break;
+
+ monitor = find_monitor_by_name(screen, name_ptr);
+ if(monitor)
+ {
+ monitor->keystone_vertical = values[i*4]/10000.0f;
+ monitor->cylinder_depth = values[i*4+1]/10000.0f;
+ monitor->vertical_center = values[i*4+2]/10000.0f;
+ monitor->perspective = values[i*4+3]/10000.0f;
+
+ update_monitor_vertices(screen, monitor);
+ }
+
+ name_ptr += strlen(name_ptr)+1;
+ }
+
+ XFree(names);
+ XFree(values);
+}
+