glx (new backend): Add some missing functions

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

src/backend/gl/gl_common.c

@@ -223,7 +223,7 @@ bool gl_compose(const gl_texture_t *ptex, int x, int y, int dx, int dy, int widt
 	}
 
 	// Programmable path
-	assert(shader->prog);
+	if (shader->prog) {
 		glUseProgram(shader->prog);
 		if (shader->unifm_opacity >= 0)
 			glUniform1f(shader->unifm_opacity, opacity);
@@ -231,6 +231,7 @@ bool gl_compose(const gl_texture_t *ptex, int x, int y, int dx, int dy, int widt
 			glUniform1i(shader->unifm_invert_color, neg);
 		if (shader->unifm_tex >= 0)
 			glUniform1i(shader->unifm_tex, 0);
+	}
 
 	// log_trace("Draw: %d, %d, %d, %d -> %d, %d (%d, %d) z %d\n",
 	//          x, y, width, height, dx, dy, ptex->width, ptex->height, z);

src/backend/gl/gl_common.h

@@ -69,6 +69,12 @@ GLuint gl_create_shader(GLenum shader_type, const char *shader_str);
 GLuint gl_create_program(const GLuint *const shaders, int nshaders);
 GLuint
 gl_create_program_from_str(const char *vert_shader_str, const char *frag_shader_str);
+/**
+ * @brief Render a region with texture data.
+ */
+bool gl_compose(const gl_texture_t *ptex, int x, int y, int dx, int dy, int width,
+                int height, int z, double opacity, bool argb, bool neg,
+                const region_t *reg_tgt, const gl_win_shader_t *shader);
 
 bool gl_load_prog_main(session_t *ps, const char *vshader_str, const char *fshader_str,
                        gl_win_shader_t *pprogram);

src/backend/gl/glx.c

@@ -101,8 +101,10 @@ static void glx_release_pixmap(struct _glx_data *gd, Display *dpy, struct _glx_w
 /**
  * Free a glx_texture_t.
  */
-static void attr_unused glx_release_win(struct _glx_data *gd, Display *dpy, struct _glx_win_data *wd) {
-	glx_release_pixmap(gd, dpy, wd);
+static void glx_release_win(void *backend_data, session_t *ps, win *w, void *win_data) {
+	struct _glx_win_data *wd = win_data;
+	struct _glx_data *gd = backend_data;
+	glx_release_pixmap(gd, ps->dpy, wd);
 	glDeleteTextures(1, &wd->texture.texture);
 
 	// Free structure itself
@@ -472,7 +474,7 @@ static void *glx_init(session_t *ps) {
 	// glXSwapBuffers(ps->dpy, get_tgt_window(ps));
 
 	// Initialize blur filters
-	gl_create_blur_filters(ps, gd->blur_shader, &gd->cap);
+	// gl_create_blur_filters(ps, gd->blur_shader, &gd->cap);
 
 	success = true;
 
@@ -596,13 +598,35 @@ static void glx_present(void *backend_data, session_t *ps) {
 	glXSwapBuffers(ps->dpy, ps->overlay != XCB_NONE ? ps->overlay : ps->root);
 }
 
+static int glx_buffer_age(void *backend_data, session_t *ps) {
+	if (ps->o.glx_swap_method == SWAPM_BUFFER_AGE) {
+		unsigned int val;
+		glXQueryDrawable(ps->dpy, get_tgt_window(ps), GLX_BACK_BUFFER_AGE_EXT, &val);
+		return (int)val ?: -1;
+	} else {
+		return -1;
+	}
+}
+
+static void glx_compose(void *backend_data, session_t *ps, win *w, void *win_data,
+                       int dst_x, int dst_y, const region_t *region) {
+	struct _glx_data *gd = backend_data;
+	struct _glx_win_data *wd = win_data;
+
+	gl_compose(&wd->texture, 0, 0, dst_x, dst_y, w->widthb, w->heightb, 0, 0, false,
+	           false, region, &gd->win_shader);
+}
+
 backend_info_t glx_backend = {
     .init = glx_init,
     .deinit = glx_deinit,
     .prepare_win = glx_prepare_win,
     .render_win = glx_render_win,
+    .release_win = glx_release_win,
     .present = glx_present,
+    .compose = glx_compose,
     .is_win_transparent = default_is_win_transparent,
     .is_frame_transparent = default_is_frame_transparent,
+    .buffer_age = glx_buffer_age,
     .max_buffer_age = 5,        // XXX why?
 };