--- /dev/null
+#define GL_GLEXT_PROTOTYPES
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <X11/Xlib.h>
+#include <X11/extensions/Xcomposite.h>
+#include <X11/extensions/Xdamage.h>
+#include <GL/gl.h>
+#include <GL/glx.h>
+
+typedef struct CompositedWindow
+{
+ Window window;
+ int x;
+ int y;
+ unsigned width;
+ unsigned height;
+ int map_state;
+ Damage damage;
+ Pixmap pixmap;
+ GLXPixmap glx_pixmap;
+ unsigned texture;
+} CompositedWindow;
+
+typedef struct CompositedScreen
+{
+ int number;
+ Window root;
+ unsigned width;
+ unsigned height;
+ Window overlay;
+ Window render_window;
+ GLXFBConfig fbconfig;
+ GLXWindow glx_window;
+ GLXContext glx_context;
+ unsigned shaders[2];
+ unsigned program;
+ unsigned geometry_loc;
+ unsigned vertex_buffer;
+ unsigned vertex_array;
+ CompositedWindow *windows;
+ unsigned nwindows;
+ unsigned windows_capacity;
+} CompositedScreen;
+
+typedef struct Compositor
+{
+ Display *display;
+ CompositedScreen *screens;
+ unsigned nscreens;
+ int damage_event;
+ PFNGLXCREATECONTEXTATTRIBSARBPROC glXCreateContextAttribsARB;
+ PFNGLXBINDTEXIMAGEEXTPROC glXBindTexImageEXT;
+ PFNGLXRELEASETEXIMAGEEXTPROC glXReleaseTexImageEXT;
+} Compositor;
+
+static const char *vshader =
+ "#version 150\n"
+ "uniform vec4 geometry;\n"
+ "in vec2 vertex;\n"
+ "out vec2 texcoord;\n"
+ "void main()\n"
+ "{\n"
+ " gl_Position = vec4((geometry.xy+vertex*geometry.zw)*2.0-1.0, 0.0, 1.0);\n"
+ " texcoord = vec2(vertex.x, 1.0-vertex.y);\n"
+ "}\n";
+
+static const char *fshader =
+ "#version 150\n"
+ "uniform sampler2D window;\n"
+ "in vec2 texcoord;\n"
+ "out vec4 frag_color;\n"
+ "void main()\n"
+ "{\n"
+ " frag_color = texture(window, texcoord);\n"
+ "}\n";
+
+static const float vertices[] =
+{
+ 0.0f, 1.0f,
+ 0.0f, 0.0f,
+ 1.0f, 1.0f,
+ 1.0f, 0.0f
+};
+
+int with_error(const char *message)
+{
+ fprintf(stderr, "%s\n", message);
+ return 0;
+}
+
+int initialize_gl(Compositor *compositor, CompositedScreen *screen)
+{
+ int attribs[9];
+ unsigned i;
+ GLXFBConfig *configs;
+ int nconfigs;
+ XVisualInfo *vi;
+ XSetWindowAttributes win_attr;
+
+ i = 0;
+ attribs[i++] = GLX_DRAWABLE_TYPE;
+ attribs[i++] = GLX_WINDOW_BIT;
+ attribs[i++] = GLX_RENDER_TYPE;
+ attribs[i++] = GLX_RGBA_BIT;
+ attribs[i++] = GLX_DOUBLEBUFFER;
+ attribs[i++] = True;
+ attribs[i++] = GLX_BIND_TO_TEXTURE_RGBA_EXT;
+ attribs[i++] = True;
+ attribs[i] = None;
+
+ configs = glXChooseFBConfig(compositor->display, screen->number, attribs, &nconfigs);
+ if(!configs || !nconfigs)
+ return with_error("Could not find a suitable FBConfig");
+ screen->fbconfig = configs[0];
+ XFree(configs);
+
+ vi = glXGetVisualFromFBConfig(compositor->display, screen->fbconfig);
+ win_attr.colormap = XCreateColormap(compositor->display, screen->root, vi->visual, AllocNone);
+ screen->render_window = XCreateWindow(compositor->display, screen->overlay, 0, 0, screen->width, screen->height, 0, vi->depth, InputOutput, vi->visual, CWColormap, &win_attr);
+ XMapWindow(compositor->display, screen->render_window);
+
+ screen->glx_window = glXCreateWindow(compositor->display, screen->fbconfig, screen->render_window, NULL);
+
+ i = 0;
+ attribs[i++] = GLX_CONTEXT_FLAGS_ARB;
+ attribs[i++] = GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
+ attribs[i++] = GLX_CONTEXT_MAJOR_VERSION_ARB;
+ attribs[i++] = 3;
+ attribs[i++] = GLX_CONTEXT_MINOR_VERSION_ARB;
+ attribs[i++] = 0;
+ attribs[i] = None;
+
+ screen->glx_context = compositor->glXCreateContextAttribsARB(compositor->display, screen->fbconfig, NULL, True, attribs);
+
+ XFree(vi);
+
+ return 1;
+}
+
+void use_gl(Compositor *compositor, CompositedScreen *screen)
+{
+ glXMakeContextCurrent(compositor->display, screen->glx_window, screen->glx_window, screen->glx_context);
+}
+
+unsigned compile_shader(GLenum type, const char *source)
+{
+ unsigned shader;
+ int status;
+ char info_log[1024];
+ GLsizei length;
+
+ shader = glCreateShader(type);
+ glShaderSource(shader, 1, &source, NULL);
+ glCompileShader(shader);
+ glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
+ glGetShaderInfoLog(shader, sizeof(info_log), &length, info_log);
+ if(!status)
+ {
+ fprintf(stderr, "Shader compilation failed:\n%s\n", info_log);
+ glDeleteShader(shader);
+ return 0;
+ }
+ else if(length)
+ printf("Shader info log:\n%s\n", info_log);
+
+ return shader;
+}
+
+int create_gl_resources(Compositor *compositor, CompositedScreen *screen)
+{
+ int status;
+ char info_log[1024];
+ GLsizei length;
+
+ use_gl(compositor, screen);
+
+ screen->shaders[0] = compile_shader(GL_VERTEX_SHADER, vshader);
+ screen->shaders[1] = compile_shader(GL_FRAGMENT_SHADER, fshader);
+ if(!screen->shaders[0] || !screen->shaders[1])
+ return 0;
+
+ screen->program = glCreateProgram();
+ glAttachShader(screen->program, screen->shaders[0]);
+ glAttachShader(screen->program, screen->shaders[1]);
+ glBindAttribLocation(screen->program, 0, "vertex");
+ glLinkProgram(screen->program);
+
+ screen->geometry_loc = glGetUniformLocation(screen->program, "geometry");
+
+ glGetProgramiv(screen->program, GL_LINK_STATUS, &status);
+ glGetProgramInfoLog(screen->program, sizeof(info_log), &length, info_log);
+ if(!status)
+ {
+ fprintf(stderr, "Program link failed:\n%s\n", info_log);
+ glDeleteProgram(screen->program);
+ return 0;
+ }
+ else if(length)
+ printf("Program info log:\n%s\n", info_log);
+
+ glGenBuffers(1, &screen->vertex_buffer);
+ glBindBuffer(GL_ARRAY_BUFFER, screen->vertex_buffer);
+ glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+ glGenVertexArrays(1, &screen->vertex_array);
+ glBindVertexArray(screen->vertex_array);
+ glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, NULL);
+ glEnableVertexAttribArray(0);
+
+ glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+ return 1;
+}
+
+CompositedWindow *find_window(CompositedScreen *screen, Window w)
+{
+ unsigned i;
+
+ for(i=0; i<screen->nwindows; ++i)
+ if(screen->windows[i].window==w)
+ return &screen->windows[i];
+
+ return NULL;
+}
+
+void create_window_pixmap(Compositor *compositor, CompositedScreen *screen, CompositedWindow *window)
+{
+ int attribs[5];
+ unsigned i;
+
+ if(window->pixmap)
+ {
+ glXDestroyPixmap(compositor->display, window->glx_pixmap);
+ XFreePixmap(compositor->display, window->pixmap);
+ }
+
+ i = 0;
+ attribs[i++] = GLX_TEXTURE_TARGET_EXT;
+ attribs[i++] = GLX_TEXTURE_2D_EXT;
+ attribs[i++] = GLX_TEXTURE_FORMAT_EXT;
+ attribs[i++] = GLX_TEXTURE_FORMAT_RGBA_EXT;
+ attribs[i++] = None;
+
+ window->pixmap = XCompositeNameWindowPixmap(compositor->display, window->window);
+ window->glx_pixmap = glXCreatePixmap(compositor->display, screen->fbconfig, window->pixmap, attribs);
+}
+
+void add_window(Compositor *compositor, CompositedScreen *screen, Window w)
+{
+ CompositedWindow *window;
+ XWindowAttributes win_attr;
+
+ if(w==screen->root || w==screen->overlay)
+ return;
+
+ XGetWindowAttributes(compositor->display, w, &win_attr);
+ if(win_attr.class==InputOnly)
+ return;
+
+ if(find_window(screen, w))
+ return;
+
+ if(screen->nwindows==screen->windows_capacity)
+ {
+ screen->windows = (CompositedWindow *)realloc(screen->windows, (screen->windows_capacity+1)*sizeof(CompositedWindow));
+ ++screen->windows_capacity;
+ }
+
+ window = &screen->windows[screen->nwindows++];
+
+ window->window = w;
+ window->x = win_attr.x;
+ window->y = win_attr.y;
+ window->width = win_attr.width;
+ window->height = win_attr.height;
+ window->map_state = win_attr.map_state;
+
+ window->damage = XDamageCreate(compositor->display, window->window, XDamageReportNonEmpty);
+ window->pixmap = None;
+ window->glx_pixmap = None;
+
+ XCompositeRedirectWindow(compositor->display, window->window, CompositeRedirectManual);
+ if(window->map_state==IsViewable)
+ create_window_pixmap(compositor, screen, window);
+
+ glGenTextures(1, &window->texture);
+ glBindTexture(GL_TEXTURE_2D, window->texture);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+}
+
+CompositedScreen *find_screen_by_root(Compositor *compositor, Window root)
+{
+ unsigned i;
+
+ for(i=0; i<compositor->nscreens; ++i)
+ if(compositor->screens[i].root==root)
+ return &compositor->screens[i];
+
+ return NULL;
+}
+
+int initialize_screen(Compositor *compositor, unsigned number)
+{
+ CompositedScreen *screen;
+ const char *extensions;
+ Window dummy_root;
+ int x, y;
+ unsigned border;
+ unsigned depth;
+ Window dummy_parent;
+ Window *children;
+ unsigned nchildren;
+ unsigned i;
+
+ screen = &compositor->screens[number];
+ screen->number = number;
+
+ extensions = glXQueryExtensionsString(compositor->display, screen->number);
+ if(!strstr(extensions, "GLX_ARB_create_context"))
+ return with_error("GLX_ARB_create_context is required");
+ if(!strstr(extensions, "GLX_EXT_texture_from_pixmap"))
+ return with_error("GLX_EXT_texture_from_pixmap is required");
+
+ screen->root = RootWindow(compositor->display, screen->number);
+ XSelectInput(compositor->display, screen->root, SubstructureNotifyMask);
+ screen->overlay = XCompositeGetOverlayWindow(compositor->display, screen->root);
+ XGetGeometry(compositor->display, screen->overlay, &dummy_root, &x, &y, &screen->width, &screen->height, &border, &depth);
+
+ if(!initialize_gl(compositor, screen))
+ return 0;
+
+ if(!create_gl_resources(compositor, screen))
+ return 0;
+
+ XQueryTree(compositor->display, screen->root, &dummy_root, &dummy_parent, &children, &nchildren);
+
+ screen->windows = (CompositedWindow *)malloc(nchildren*sizeof(CompositedWindow));
+ screen->nwindows = 0;
+ screen->windows_capacity = nchildren;
+
+ for(i=0; i<nchildren; ++i)
+ add_window(compositor, screen, children[i]);
+
+ XFree(children);
+
+ return 1;
+}
+
+int initialize_compositor(Compositor *compositor)
+{
+ int event_base;
+ int error_base;
+ int major_ver;
+ int minor_ver;
+ unsigned i;
+
+ compositor->display = XOpenDisplay(NULL);
+ if(!compositor->display)
+ return with_error("Could not open X display");
+
+ if(!XCompositeQueryExtension(compositor->display, &event_base, &error_base))
+ return with_error("XComposite is required but was not found");
+ else if(!XCompositeQueryVersion(compositor->display, &major_ver, &minor_ver))
+ return with_error("Cannot determine XComposite version");
+ else if(major_ver==0 && minor_ver<3)
+ return with_error("XComposite 0.3 or later is required");
+
+ if(!glXQueryExtension(compositor->display, &event_base, &error_base))
+ return with_error("GLX is required but was not found");
+ else if(!glXQueryVersion(compositor->display, &major_ver, &minor_ver))
+ return with_error("Cannot determine GLX version");
+ else if(major_ver<1 || (major_ver==1 && minor_ver<4))
+ return with_error("GLX 1.4 or later is required");
+
+ if(!XDamageQueryExtension(compositor->display, &compositor->damage_event, &error_base))
+ return with_error("XDamage is required but was not found");
+ else if(!XDamageQueryVersion(compositor->display, &major_ver, &minor_ver))
+ return with_error("Cannot determine XDamage version");
+ else if(major_ver<1)
+ return with_error("XDamage 1.0 or later is required");
+
+ compositor->glXCreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)glXGetProcAddress((unsigned char *)"glXCreateContextAttribsARB");
+ compositor->glXBindTexImageEXT = (PFNGLXBINDTEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXBindTexImageEXT");
+ compositor->glXReleaseTexImageEXT = (PFNGLXRELEASETEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXReleaseTexImageEXT");
+
+ compositor->nscreens = ScreenCount(compositor->display);
+ compositor->screens = (CompositedScreen *)malloc(compositor->nscreens*sizeof(CompositedScreen));
+ for(i=0; i<compositor->nscreens; ++i)
+ if(!initialize_screen(compositor, i))
+ return 0;
+
+ return 1;
+}
+
+void shutdown_screen(Compositor *compositor, CompositedScreen *screen)
+{
+ glXDestroyContext(compositor->display, screen->glx_context);
+ glXDestroyWindow(compositor->display, screen->glx_window);
+ XDestroyWindow(compositor->display, screen->render_window);
+
+ XCompositeReleaseOverlayWindow(compositor->display, screen->overlay);
+}
+
+void shutdown_compositor(Compositor *compositor)
+{
+ unsigned i;
+
+ glXMakeContextCurrent(compositor->display, 0, 0, NULL);
+ for(i=0; i<compositor->nscreens; ++i)
+ shutdown_screen(compositor, &compositor->screens[i]);
+}
+
+void process_create_window_event(Compositor *compositor, XCreateWindowEvent *event)
+{
+ CompositedScreen *screen = find_screen_by_root(compositor, event->parent);
+ if(!screen)
+ return;
+
+ add_window(compositor, screen, event->window);
+}
+
+void process_map_event(Compositor *compositor, XMapEvent *event)
+{
+ CompositedScreen *screen = find_screen_by_root(compositor, event->event);
+ if(!screen)
+ return;
+
+ CompositedWindow *window = find_window(screen, event->window);
+ if(window)
+ {
+ window->map_state = IsViewable;
+ create_window_pixmap(compositor, screen, window);
+ }
+}
+
+void process_unmap_event(Compositor *compositor, XUnmapEvent *event)
+{
+ CompositedScreen *screen = find_screen_by_root(compositor, event->event);
+ if(!screen)
+ return;
+
+ CompositedWindow *window = find_window(screen, event->window);
+ if(window)
+ window->map_state = IsUnviewable;
+}
+
+void process_event(Compositor *compositor)
+{
+ XEvent event;
+ XNextEvent(compositor->display, &event);
+ switch(event.type)
+ {
+ case CreateNotify:
+ process_create_window_event(compositor, &event.xcreatewindow);
+ break;
+ case MapNotify:
+ process_map_event(compositor, &event.xmap);
+ break;
+ case UnmapNotify:
+ process_unmap_event(compositor, &event.xunmap);
+ break;
+ default:
+ if(event.type!=compositor->damage_event+XDamageNotify)
+ printf("Event %d\n", event.type);
+ }
+}
+
+void refresh_screens(Compositor *compositor)
+{
+ unsigned i, j;
+
+ for(i=0; i<compositor->nscreens; ++i)
+ {
+ CompositedScreen *screen = &compositor->screens[i];
+ use_gl(compositor, screen);
+
+ glClearColor(0.5f, 0.5f, 0.5f, 0.0f);
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ glUseProgram(screen->program);
+ glBindVertexArray(screen->vertex_array);
+ XGrabServer(compositor->display);
+ glXWaitX();
+ for(j=0; j<screen->nwindows; ++j)
+ {
+ CompositedWindow *window = &screen->windows[j];
+ if(window->map_state==IsViewable)
+ {
+ glBindTexture(GL_TEXTURE_2D, window->texture);
+ compositor->glXBindTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT, NULL);
+ glUniform4f(screen->geometry_loc, (float)window->x/screen->width, (float)(screen->height-window->y-window->height)/screen->height, (float)window->width/screen->width, (float)window->height/screen->height);
+ glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+ compositor->glXReleaseTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT);
+ XDamageSubtract(compositor->display, window->damage, None, None);
+ }
+ }
+ XUngrabServer(compositor->display);
+ glXSwapBuffers(compositor->display, screen->glx_window);
+ }
+}
+
+int main()
+{
+ Compositor compositor;
+
+ if(!initialize_compositor(&compositor))
+ return 1;
+
+ while(1)
+ {
+ process_event(&compositor);
+ refresh_screens(&compositor);
+ }
+
+ shutdown_compositor(&compositor);
+
+ return 0;
+}
projects / geometrycompositor.git / commitdiff