build: make opengl optional

This removes the mode where we compiled uterm with OpenGL instead of
OpenGLES2 (it was broken anyway) and makes it fully optional now.

gl_shader.h is no longer compiled if OpenGL is not available and provides
dummy helpers instead.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

diff --git a/Makefile.am b/Makefile.am
index 9572425..ff8c876 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -118,17 +118,21 @@ libkmscon_core_la_SOURCES = \
        src/pty.c src/pty.h \
        src/gl.h \
        src/gl_math.c \
-       src/gl_shader.c \
        src/font_pango.c
 
+if KMSCON_HAVE_GLES2
+libkmscon_core_la_SOURCES += \
+       src/gl_shader.c
+endif
+
 libkmscon_core_la_CPPFLAGS = \
        $(AM_CPPFLAGS) \
-       $(OPENGLES2_CFLAGS) \
+       $(GLES2_CFLAGS) \
        $(PANGO_CFLAGS) \
        $(FREETYPE2_CFLAGS) \
        $(GLIB_CFLAGS)
 libkmscon_core_la_LIBADD = \
-       $(OPENGLES2_LIBS) \
+       $(GLES2_LIBS) \
        $(PANGO_LIBS) \
        $(FREETYPE2_LIBS) \
        $(GLIB_LIBS) \
@@ -160,8 +164,7 @@ libuterm_la_CPPFLAGS = \
        $(DRM_CFLAGS) \
        $(EGL_CFLAGS) \
        $(GBM_CFLAGS) \
-       $(OPENGL_CFLAGS) \
-       $(OPENGLES2_CFLAGS) \
+       $(GLES2_CFLAGS) \
        $(UDEV_CFLAGS) \
        $(XKBCOMMON_CFLAGS)
 libuterm_la_LIBADD = \
@@ -169,8 +172,7 @@ libuterm_la_LIBADD = \
        $(DRM_LIBS) \
        $(EGL_LIBS) \
        $(GBM_LIBS) \
-       $(OPENGL_LIBS) \
-       $(OPENGLES2_LIBS) \
+       $(GLES2_LIBS) \
        $(UDEV_LIBS) \
        $(XKBCOMMON_LIBS) \
        libkmscon-static.la \

diff --git a/configure.ac b/configure.ac
index 0909dad..5c32524 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -70,10 +70,7 @@ PKG_CHECK_MODULES([GBM], [gbm],
 PKG_CHECK_MODULES([EGL], [egl],
                   [have_egl=yes], [have_egl=no])
 
-PKG_CHECK_MODULES([OPENGL], [gl],
-                  [have_gl=yes], [have_gl=no])
-
-PKG_CHECK_MODULES([OPENGLES2], [glesv2],
+PKG_CHECK_MODULES([GLES2], [glesv2],
                   [have_gles2=yes], [have_gles2=no])
 
 PKG_CHECK_MODULES([XKBCOMMON], [xkbcommon],
@@ -115,10 +112,10 @@ AC_ARG_ENABLE([drm],
                               [enable uterm drm video backend])])
 AC_MSG_RESULT([ok])
 
-AC_MSG_CHECKING([whether to provide OpenGL support])
-AC_ARG_ENABLE([opengl],
-              [AS_HELP_STRING([--enable-opengl],
-                              [provide uterm opengl support])])
+AC_MSG_CHECKING([whether to provide OpenGLES2 support])
+AC_ARG_ENABLE([gles2],
+              [AS_HELP_STRING([--enable-gles2],
+                              [provide uterm OpenGLES2 support])])
 AC_MSG_RESULT([ok])
 
 AC_MSG_CHECKING([whether to use xkbcommon keyboard backend])
@@ -243,23 +240,17 @@ AM_CONDITIONAL([UTERM_HAVE_FBDEV], [test x$fbdev_enabled = xyes])
 
 dumb_enabled=no
 drm_enabled=no
-gl_enabled=no
 gles2_enabled=no
 if test ! x$enable_drm = xno ; then
         if test x$have_drm = xyes ; then
                 dumb_enabled=yes
         fi
 
-        if test ! x$enable_opengl = xno ; then
+        if test ! x$enable_gles2 = xno ; then
                 if test x$have_drm = xyes -a x$have_gbm = xyes -a x$have_egl = xyes ; then
-                        if test x$have_gl = xyes -o x$have_gles2 = xyes ; then
+                        if test x$have_gles2 = xyes ; then
                                 drm_enabled=yes
-                                if test x$have_gl = xyes ; then
-                                        gl_enabled=yes
-                                fi
-                                if test x$have_gles2 = xyes ; then
-                                        gles2_enabled=yes
-                                fi
+                                gles2_enabled=yes
                         fi
                 fi
         fi
@@ -268,14 +259,14 @@ if test ! x$enable_drm = xno ; then
                 AC_ERROR([drm library not found for uterm dumb drm backend])
         fi
 
-        if test x$enable_opengl = xyes -a x$drm_enabled = xno ; then
+        if test x$enable_gles2 = xyes -a x$drm_enabled = xno ; then
                 AC_ERROR([drm, gbm, egl, gl or gles2 libraries not found for uterm drm backend])
         fi
 fi
 
 if test x$dumb_enabled = xyes ; then
         AC_DEFINE([UTERM_HAVE_DUMB], [1],
-                  [Use uterm dubm drm video backend])
+                  [Use uterm dumb drm video backend])
 
         if test x$drm_enabled = xyes ; then
                 AC_DEFINE([UTERM_HAVE_DRM], [1],
@@ -291,25 +282,18 @@ else
         DRM_LIBS=""
 fi
 
-AM_CONDITIONAL([UTERM_HAVE_DUMB], [test x$dumb_enabled = xyes])
-AM_CONDITIONAL([UTERM_HAVE_DRM], [test x$drm_enabled = xyes])
-
-if test x$gl_enabled = xyes ; then
-        AC_DEFINE([UTERM_HAVE_GL], [1],
-                  [Use OpenGL as drawing backend])
-else
-        OPENGL_CFLAGS=""
-        OPENGL_LIBS=""
-fi
-
 if test x$gles2_enabled = xyes ; then
-        AC_DEFINE([UTERM_HAVE_GLES2], [1],
+        AC_DEFINE([KMSCON_HAVE_GLES2], [1],
                   [Use OpenGLESv2 as drawing backend])
 else
-        OPENGLES2_CFLAGS=""
-        OPENGLES2_LIBS=""
+        GLES2_CFLAGS=""
+        GLES2_LIBS=""
 fi
 
+AM_CONDITIONAL([UTERM_HAVE_DUMB], [test x$dumb_enabled = xyes])
+AM_CONDITIONAL([UTERM_HAVE_DRM], [test x$drm_enabled = xyes])
+AM_CONDITIONAL([KMSCON_HAVE_GLES2], [test x$gles2_enabled = xyes])
+
 #
 # xkbcommon keyboard backend
 # This checks for the xkbcommon library for keyboard handling in uterm. If it is
@@ -348,10 +332,8 @@ AC_SUBST(EGL_CFLAGS)
 AC_SUBST(EGL_LIBS)
 AC_SUBST(GBM_CFLAGS)
 AC_SUBST(GBM_LIBS)
-AC_SUBST(OPENGLES2_CFLAGS)
-AC_SUBST(OPENGLES2_LIBS)
-AC_SUBST(OPENGL_CFLAGS)
-AC_SUBST(OPENGL_LIBS)
+AC_SUBST(GLES2_CFLAGS)
+AC_SUBST(GLES2_LIBS)
 AC_SUBST(UDEV_CFLAGS)
 AC_SUBST(UDEV_LIBS)
 AC_SUBST(XKBCOMMON_CFLAGS)
@@ -384,7 +366,6 @@ AC_MSG_NOTICE([Build configuration:
                fbdev: $fbdev_enabled
             dumb drm: $dumb_enabled
                  drm: $drm_enabled
-              opengl: $gl_enabled
-           opengles2: $gles2_enabled
+           OpenGLES2: $gles2_enabled
 
        Run "make" to start compilation process])

diff --git a/src/gl.h b/src/gl.h
index 06182de..f25508d 100644 (file)
--- a/src/gl.h
+++ b/src/gl.h
@@ -37,13 +37,6 @@
 #include <stdlib.h>
 #include "uterm.h"
 
-/* miscellaneous */
-void gl_clear_error();
-bool gl_has_error();
-void gl_viewport(struct uterm_screen *screen);
-void gl_clear_color(float r, float g, float b, float a);
-void gl_clear(void);
-
 /*
  * Math Helpers
  * The gl_m4 type is a 4x4 matrix of floats. The gl_m4_stack is a stack of m4
@@ -67,6 +60,15 @@ float *gl_m4_stack_push(struct gl_m4_stack *stack);
 float *gl_m4_stack_pop(struct gl_m4_stack *stack);
 float *gl_m4_stack_tip(struct gl_m4_stack *stack);
 
+#ifdef KMSCON_HAVE_GLES2
+
+/* miscellaneous */
+void gl_clear_error();
+bool gl_has_error();
+void gl_viewport(struct uterm_screen *screen);
+void gl_clear_color(float r, float g, float b, float a);
+void gl_clear(void);
+
 /*
  * Texture API
  * This allows to create new textures which can then be used to draw images with
@@ -94,4 +96,87 @@ void gl_shader_draw_tex(struct gl_shader *shader, const float *vertices,
                        const float *texcoords, size_t num,
                        unsigned int tex, const float *m);
 
+#else /* !KMSCON_HAVE_GLES2 */
+
+/* dummy helpers for the case that OpenGL is not available */
+
+static inline void gl_clear_error()
+{
+}
+
+static inline bool gl_has_error()
+{
+       return false;
+}
+
+static inline void gl_viewport(struct uterm_screen *screen)
+{
+}
+
+static inline void gl_clear_color(float r, float g, float b, float a)
+{
+}
+
+static inline void gl_clear(void)
+{
+}
+
+/*
+ * Texture API
+ * This allows to create new textures which can then be used to draw images with
+ * the shader API.
+ */
+
+static inline unsigned int gl_tex_new()
+{
+       return 1;
+}
+
+static inline void gl_tex_free(unsigned int tex)
+{
+}
+
+static inline void gl_tex_load(unsigned int tex, unsigned int width,
+                              unsigned int stride,
+                              unsigned int height, void *buf)
+{
+}
+
+/*
+ * Shader API
+ */
+
+struct gl_shader {
+       int unused;
+};
+
+static inline int gl_shader_new(struct gl_shader **out)
+{
+       *out = NULL;
+       return 0;
+}
+
+static inline void gl_shader_ref(struct gl_shader *shader)
+{
+}
+
+static inline void gl_shader_unref(struct gl_shader *shader)
+{
+}
+
+static inline void gl_shader_draw_def(struct gl_shader *shader,
+                                     float *vertices,
+                                     float *colors, size_t num)
+{
+}
+
+static inline void gl_shader_draw_tex(struct gl_shader *shader,
+                                     const float *vertices,
+                                     const float *texcoords, size_t num,
+                                     unsigned int tex, const float *m)
+{
+}
+
+#endif /* KMSCON_HAVE_GLES2 */
+
 #endif /* GL_GL_H */