[DRM] open with drmModeGetResources()

CMakeLists.txt

@@ -232,6 +232,7 @@ target_include_directories(notcurses-core
     "${PROJECT_BINARY_DIR}/include"
     "${TERMINFO_INCLUDE_DIRS}"
     "${ZLIB_INCLUDE_DIRS}"
+    "${DRM_INCLUDE_DIRS}"
 )
 target_include_directories(notcurses-core-static
   BEFORE
@@ -242,6 +243,7 @@ target_include_directories(notcurses-core-static
     "${PROJECT_BINARY_DIR}/include"
     "${TERMINFO_STATIC_INCLUDE_DIRS}"
     "${ZLIB_STATIC_INCLUDE_DIRS}"
+    "${DRM_STATIC_INCLUDE_DIRS}"
 )
 target_link_libraries(notcurses-core
   PRIVATE

USAGE.md

@@ -354,7 +354,6 @@ typedef enum {
   NCPIXEL_NONE = 0,
   NCPIXEL_SIXEL,           // sixel
   NCPIXEL_LINUXFB,         // linux framebuffer
-  NCPIXEL_ITERM2,          // iTerm2
   // C=1 (disabling scrolling) was only introduced in 0.20.0, at the same
   // time as animation. prior to this, graphics had to be entirely redrawn
   // on any change, and it wasn't possible to use the bottom line.
@@ -368,6 +367,7 @@ typedef enum {
   // original image (which we now deflate, since we needn't unpack it later).
   // the only data we need keep is the auxvecs.
   NCPIXEL_KITTY_SELFREF,
+  NCPIXEL_DRM,             // direct rendering manager (unix)
 } ncpixelimpl_e;
 
 // Returns a non-zero constant corresponding to some pixel-blitting

doc/man/man3/notcurses_capabilities.3.md

@@ -43,10 +43,10 @@ typedef enum {
   NCPIXEL_NONE = 0,
   NCPIXEL_SIXEL,           // sixel
   NCPIXEL_LINUXFB,         // linux framebuffer
-  NCPIXEL_ITERM2,          // iTerm2
   NCPIXEL_KITTY_STATIC,    // kitty pre-0.20.0
   NCPIXEL_KITTY_ANIMATED,  // kitty pre-0.22.0
   NCPIXEL_KITTY_SELFREF,   // kitty 0.22.0+, wezterm
+  NCPIXEL_DRM,             // direct rendering manager
 } ncpixelimpl_e;
 ```
 

include/notcurses/notcurses.h

@@ -1418,7 +1418,6 @@ typedef enum {
   NCPIXEL_NONE = 0,
   NCPIXEL_SIXEL,           // sixel
   NCPIXEL_LINUXFB,         // linux framebuffer
-  NCPIXEL_ITERM2,          // iTerm2
   // C=1 (disabling scrolling) was only introduced in 0.20.0, at the same
   // time as animation. prior to this, graphics had to be entirely redrawn
   // on any change, and it wasn't possible to use the bottom line.
@@ -1432,6 +1431,7 @@ typedef enum {
   // original image (which we now deflate, since we needn't unpack it later).
   // the only data we need keep is the auxvecs.
   NCPIXEL_KITTY_SELFREF,
+  NCPIXEL_DRM,             // direct rendering manager (unix)
 } ncpixelimpl_e;
 
 // Can we blit pixel-accurate bitmaps?

src/info/main.c

@@ -386,8 +386,8 @@ tinfo_debug_bitmaps(struct ncplane* n, const tinfo* ti, const char* indent){
     case NCPIXEL_LINUXFB:
       ncplane_printf(n, "%sframebuffer graphics supported", indent);
       break;
-    case NCPIXEL_ITERM2:
-      ncplane_printf(n, "%siTerm2 graphics supported", indent);
+    case NCPIXEL_DRM:
+      ncplane_printf(n, "%sDRM graphics supported", indent);
       break;
     case NCPIXEL_KITTY_STATIC:
       ncplane_printf(n, "%srgba pixel graphics support", indent);

src/lib/linux.c

@@ -737,11 +737,41 @@ int get_linux_fb_pixelgeom(tinfo* ti, unsigned* ypix, unsigned *xpix){
   return 0;
 }
 
+#ifdef USE_DRM
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+bool is_linux_drm(tinfo* ti){
+  // FIXME need check for multiple devices! same problem below for framebuffers
+  const char* dev = "/dev/dri/card1";
+  loginfo("checking for linux drm at %s\n", dev);
+  int fd = open(dev, O_RDWR | O_CLOEXEC);
+  if(fd < 0){
+    logdebug("couldn't open drm device %s\n", dev);
+    return false;
+  }
+  drmModeResPtr dptr = drmModeGetResources(fd);
+  if(dptr == NULL){
+    close(fd);
+    return false;
+  }
+  loginfo("found drm on %s (fd %d)\n", dev, fd);
+  close(fd);
+  // FIXME
+  return true;
+}
+#else
+bool is_linux_drm(tinfo* ti){
+  (void)ti;
+  return false;
+}
+#endif
+
 bool is_linux_framebuffer(tinfo* ti){
   // FIXME there might be multiple framebuffers present; how do we determine
   // which one is ours?
   const char* dev = "/dev/fb0";
-  loginfo("Checking for Linux framebuffer at %s\n", dev);
+  loginfo("checking for linux framebuffer at %s\n", dev);
   int fd = open(dev, O_RDWR | O_CLOEXEC);
   if(fd < 0){
     logdebug("Couldn't open framebuffer device %s\n", dev);

src/lib/linux.h

@@ -26,6 +26,10 @@ bool is_linux_console(int fd);
 int reprogram_console_font(struct tinfo* ti, unsigned no_font_changes,
                            bool* halfblocks, bool* quadrants);
 
+// if is_linux_console() returned true, call this to determine whether it is
+// a drawable DRM buffer. do not call if not a verified console!
+bool is_linux_drm(struct tinfo* ti);
+
 // if is_linux_console() returned true, call this to determine whether it is
 // a drawable framebuffer console. do not call if not a verified console!
 bool is_linux_framebuffer(struct tinfo* ti);

src/lib/termdesc.c

@@ -114,7 +114,7 @@ setup_kitty_bitmaps(tinfo* ti, int fd, ncpixelimpl_e level){
 
 #ifdef __linux__
 static inline void
-setup_fbcon_bitmaps(tinfo* ti, int fd){
+setup_fbcon_bitmaps(tinfo* ti, int fd, ncpixelimpl_e impl){
   ti->pixel_scrub = fbcon_scrub;
   ti->pixel_remove = NULL;
   ti->pixel_draw = NULL;
@@ -128,7 +128,7 @@ setup_fbcon_bitmaps(tinfo* ti, int fd){
   ti->pixel_wipe = fbcon_wipe;
   ti->pixel_trans_auxvec = kitty_trans_auxvec;
   set_pixel_blitter(fbcon_blit);
-  ti->pixel_implementation = NCPIXEL_LINUXFB;
+  ti->pixel_implementation = impl;
   sprite_init(ti, fd);
 }
 #endif
@@ -677,18 +677,15 @@ apply_term_heuristics(tinfo* ti, const char* termname, queried_terminals_e qterm
     // no quadrants, no sextants, no rgb, but it does have braille
 #ifdef __linux__
   }else if(qterm == TERMINAL_LINUX){
-    struct utsname un;
-    if(uname(&un) == 0){
-      ti->termversion = strdup(un.release);
-    }
-    if(is_linux_framebuffer(ti)){
-      termname = "Linux framebuffer";
-      setup_fbcon_bitmaps(ti, ti->linux_fb_fd);
+    if(is_linux_drm(ti)){
+      termname = "DRM";
+      setup_fbcon_bitmaps(ti, ti->linux_fb_fd, NCPIXEL_DRM);
+    }else if(is_linux_framebuffer(ti)){
+      termname = "FBcon";
+      setup_fbcon_bitmaps(ti, ti->linux_fb_fd, NCPIXEL_LINUXFB);
     }else{
-      termname = "Linux console";
+      termname = "Linux VT";
     }
-    ti->caps.halfblocks = false;
-    ti->caps.braille = false; // no caps.braille, no caps.sextants in linux console
     if(ti->ttyfd >= 0){
       reprogram_console_font(ti, nonewfonts, &ti->caps.halfblocks,
                              &ti->caps.quadrants);

src/lib/termdesc.h

@@ -179,7 +179,7 @@ typedef struct tinfo {
   int gpmfd;                 // connection to GPM daemon
   pthread_t gpmthread;       // thread handle for GPM watcher
 #ifdef __linux__
-  int linux_fb_fd;           // linux framebuffer device fd
+  int linux_fb_fd;           // linux drm/fbcon device fd
   char* linux_fb_dev;        // device corresponding to linux_fb_dev
   uint8_t* linux_fbuffer;    // mmap()ed framebuffer
   size_t linux_fb_len;       // size of map

tools/builddef.h.in

@@ -1,5 +1,6 @@
 // Populated by CMake; not installed
 #cmakedefine DFSG_BUILD
+#cmakedefine USE_DRM
 #cmakedefine USE_GPM
 #cmakedefine USE_QRCODEGEN
 // exclusive with USE_OIIO