Render wallpaper

1 files changed, 59 insertions, 15 deletions

diff --git a/src/compositor.c b/src/compositor.c
index 1e75d77..994404e 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -1,9 +1,14 @@
 #include "compositor.h"
+
 #include <string.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <time.h>
 
+#include <X11/Xatom.h>
+
+/* TODO: Handle wallpaper change and update on root window resize */
+
 static double clock_get_monotonic_seconds(void) {
     struct timespec ts;
     ts.tv_sec = 0;
@@ -24,15 +29,50 @@ static ngxc_window* ngxc_compositor_get_window_by_id(ngxc_compositor *self, Wind
     return NULL;
 }
 
+static Pixmap x11_wallpaper_get_pixmap(ngxc_compositor *self) {
+    const char *background_props[] = {
+        "_XROOTPMAP_ID",
+        "_XSETROOT_ID",
+        NULL
+    };
+
+    const Window root_window = DefaultRootWindow(self->dpy);
+    Pixmap wallpaper_pixmap = None;
+
+    for(int i = 0; background_props[i]; ++i) {
+        const Atom atom = XInternAtom(self->dpy, background_props[i], False);
+        Atom actual_type;
+        int actual_format;
+        unsigned long items_count;
+        unsigned long bytes_after;
+        unsigned char *prop = NULL;
+        if(XGetWindowProperty(self->dpy, root_window, atom, 0, 1, False, XA_PIXMAP, &actual_type, &actual_format, &items_count, &bytes_after, &prop) == Success && prop) {
+            wallpaper_pixmap = *(Pixmap*)prop;
+            XFree(prop);
+            break;
+        }
+
+        if(prop)
+            XFree(prop);
+    }
+
+    return wallpaper_pixmap;
+}
+
 void ngxc_compositor_init(ngxc_compositor *self, Display *dpy, Window composite_window) {
     memset(self, 0, sizeof(*self));
     self->dpy = dpy;
     self->composite_window = composite_window;
     self->frame_timer = clock_get_monotonic_seconds();
+
+    const Pixmap wallpaper_pixmap = x11_wallpaper_get_pixmap(self);
+    if(!ngxc_pixmap_texture_init(&self->wallpaper_texture, self->dpy, wallpaper_pixmap)) {
+        fprintf(stderr, "error: failed to create texture for wallpaper pixmap %ld\n", wallpaper_pixmap);
+    }
 }
 
 void ngxc_compositor_deinit(ngxc_compositor *self) {
-
+    /* TODO: Cleanup? */
 }
 
 void ngxc_compositor_add_window(ngxc_compositor *self, Window window) {
@@ -101,7 +141,7 @@ void ngxc_compositor_remove_window(ngxc_compositor *self, Window window) {
     }
 }
 
-static void render_texture(const ngxc_window *window) {
+static void render_texture(GLuint texture_id, int x, int y, int width, int height) {
     float matrix[16] = {
         1.0f, 0.0f, 0.0f, 0.0f,
         0.0f, 1.0f, 0.0f, 0.0f,
@@ -109,28 +149,28 @@ static void render_texture(const ngxc_window *window) {
         0.0f, 0.0f, 0.0f, 1.0f,
     };
 
-    matrix[0] = 1.0f / (float)window->texture.width;
-    matrix[5] = 1.0f / (float)window->texture.height;
+    matrix[0] = 1.0f / (float)width;
+    matrix[5] = 1.0f / (float)height;
 
     glMatrixMode(GL_TEXTURE);
     glLoadMatrixf(matrix);
     glMatrixMode(GL_MODELVIEW);
-    glBindTexture(GL_TEXTURE_2D, window->texture.texture_id);
+    glBindTexture(GL_TEXTURE_2D, texture_id);
 
     glColor4ub(255, 255, 255, 255);
-    //glTranslatef(window->x, window->y, 0.0f);
+    //glTranslatef(x, y, 0.0f);
     glBegin(GL_QUADS);
         glTexCoord2f(0.0f, 0.0f);
-        glVertex2f(window->x, window->y);
+        glVertex2f(x, y);
 
-        glTexCoord2f(window->texture.width, 0.0f);
-        glVertex2f(window->x + window->texture.width, window->y);
+        glTexCoord2f(width, 0.0f);
+        glVertex2f(x + width, y);
 
-        glTexCoord2f(window->texture.width, window->texture.height);
-        glVertex2f(window->x + window->texture.width, window->y + window->texture.height);
+        glTexCoord2f(width, height);
+        glVertex2f(x + width, y + height);
 
-        glTexCoord2f(0.0f, window->texture.height);
-        glVertex2f(window->x, window->y + window->texture.height);
+        glTexCoord2f(0.0f, height);
+        glVertex2f(x, y + height);
     glEnd();
     glLoadIdentity();
 
@@ -140,12 +180,16 @@ static void render_texture(const ngxc_window *window) {
 /* TODO: Skip windows that are not visible on the screen */
 /* TODO: Disable compositing for fullscreen windows, if that option is enabled */
 void ngxc_compositor_render(ngxc_compositor *self) {
-    glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
+    glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
     glClear(GL_COLOR_BUFFER_BIT);
 
+    if(self->wallpaper_texture.texture_id > 0) {
+        render_texture(self->wallpaper_texture.texture_id, 0, 0, self->wallpaper_texture.width, self->wallpaper_texture.height);
+    }
+
     for(int i = 0; i < self->num_windows; ++i) {
         const ngxc_window *window_obj = &self->windows[i];
-        render_texture(window_obj);
+        render_texture(window_obj->texture.texture_id, window_obj->x, window_obj->y, window_obj->texture.width, window_obj->texture.height);
     }
 
     const double now = clock_get_monotonic_seconds();