Mesa: improvements for use with Qt5

Among other changes, this patch makes it possible to let Mesa render into
a user-provided buffer instead of the screen. This can be achieved with
the 'eglCreateWindowSurface()' function, which takes a buffer
description as third argument.

Fixes #974.

libports/include/EGL/eglplatform.h

@@ -26,9 +26,17 @@
 #define EGLAPIENTRYP EGLAPIENTRY*
 
 typedef int   EGLNativeDisplayType;
-typedef void *EGLNativeWindowType;
 typedef void *EGLNativePixmapType;
 
+struct Genode_egl_window
+{
+	int width;
+	int height;
+	unsigned char *addr;
+};
+
+typedef struct Genode_egl_window *EGLNativeWindowType;
+
 typedef khronos_int32_t EGLint;
 
 #endif /* __eglplatform_h_ */

libports/ports/mesa.mk

@@ -27,6 +27,7 @@ $(DOWNLOAD_DIR)/$(MESA_TGZ):
 $(CONTRIB_DIR)/$(MESA_DIR): $(DOWNLOAD_DIR)/$(MESA_TGZ)
 	$(VERBOSE)tar xfz $< -C $(CONTRIB_DIR)
 	$(VERBOSE)patch -N -p0 -d $(CONTRIB_DIR)/$(MESA_DIR) < src/lib/gallium/p_state_config.patch
+	$(VERBOSE)patch -N -p1 -d $(CONTRIB_DIR)/$(MESA_DIR) < src/lib/egl/opengl_precision.patch
 	$(VERBOSE)touch $@
 
 tool/mesa/glsl:

libports/src/lib/egl/driver.cc

@@ -165,7 +165,7 @@ class Winsys : public pipe_winsys
 	                   struct pipe_surface *surf,
 	                   void *context_private)
 	{
-		PDBG("not implemented");
+		genode_framebuffer()->flush();
 	}
 
 	static struct pipe_buffer *
@@ -182,7 +182,10 @@ class Winsys : public pipe_winsys
 	                    void *ptr,
 	                    unsigned bytes)
 	{
-		PDBG("not implemented"); return 0;
+		Pipe_buffer *buf =
+			new (Genode::env()->heap()) Pipe_buffer(64, 0, bytes);
+		Genode::memcpy(buf->data(), ptr, bytes);
+		return buf;
 	}
 
 	/*
@@ -294,7 +297,7 @@ class Surface : public native_surface
 {
 	public:
 
-		enum Surface_type { TYPE_SCANOUT };
+		enum Surface_type { TYPE_SCANOUT, TYPE_WINDOW };
 
 	private:
 
@@ -303,6 +306,7 @@ class Surface : public native_surface
 		Surface_type         _type;
 		const native_config *_config;
 		int                  _width, _height;
+		unsigned char       *_addr; /* only used for TYPE_WINDOW */
 		struct pipe_texture *_textures[NUM_NATIVE_ATTACHMENTS];
 		unsigned int         _sequence_number;
 
@@ -390,10 +394,11 @@ class Surface : public native_surface
 	public:
 
 		Surface(native_display *display, Surface_type t, const native_config *config,
-		        int width, int height)
+		        int width, int height, unsigned char *addr = 0)
 		:
 			_color_format(config->color_format), _display(display), _type(t),
-			_config(config), _width(width), _height(height), _sequence_number(0)
+			_config(config), _width(width), _height(height), _addr(addr),
+			_sequence_number(0)
 		{
 			for (int i = 0; i < NUM_NATIVE_ATTACHMENTS; i++)
 				_textures[i] = 0;
@@ -528,7 +533,7 @@ class Display : public native_display
 		configs[0] = &display->_native_config;
 
 		struct native_config *config = &display->_native_config;
-		config->mode.drawableType    = GLX_PBUFFER_BIT;
+		config->mode.drawableType    = GLX_PBUFFER_BIT | GLX_WINDOW_BIT;
 
 		int r = 5, g = 6, b = 5, a = 0;
 		config->mode.swapMethod       = GLX_SWAP_EXCHANGE_OML;
@@ -591,7 +596,11 @@ class Display : public native_display
 	                       EGLNativeWindowType win,
 	                       const struct native_config *nconf)
 	{
-		PDBG("not implemented"); return 0;
+		return new (Genode::env()->heap())
+			Surface(ndpy,
+			        Surface::TYPE_WINDOW, nconf,
+			        win->width, win->height, win->addr);
+
 	}
 
 	static struct native_surface *
@@ -623,8 +632,15 @@ class Display : public native_display
 
 			/* setup mode list */
 			_mode.desc         = "Mode-genode";
+			try {
 				_mode.width        = genode_framebuffer()->width();
 				_mode.height       = genode_framebuffer()->height();
+			} catch (Genode::Parent::Service_denied) {
+				PWRN("EGL driver: could not create a Framebuffer session. "
+					 "Screen surfaces cannot be used.");
+				_mode.width  = 1;
+				_mode.height = 1;
+			}
 			_mode.refresh_rate = 100;
 			_mode_list[0]      = &_mode;
 
@@ -707,15 +723,21 @@ boolean Surface::_swap_buffers(struct native_surface *nsurf)
 	}
 #endif
 
+	if (this_surface->_type == TYPE_SCANOUT)
 		blit(data, transfer->stride, genode_framebuffer()->local_addr(),
 		     transfer->stride, transfer->stride, transfer->height);
+	else if (this_surface->_type == TYPE_WINDOW)
+		blit(data, transfer->stride, this_surface->_addr,
+		     transfer->stride, transfer->stride, transfer->height);
 
 	screen->transfer_unmap(screen, transfer);
 	screen->tex_transfer_destroy(transfer);
 
 	this_surface->_sequence_number++;
 
+	if (this_surface->_type == TYPE_SCANOUT)
 		genode_framebuffer()->flush();
+
 	return TRUE;
 }
 

libports/src/lib/egl/opengl_precision.patch

@@ -0,0 +1,25 @@
+Allow OpenGL precision qualifiers for Qt5
+
+From: Christian Prochaska <christian.prochaska@genode-labs.com>
+
+Qt5 creates shader programs which use precision qualifiers. When these
+programs get compiled for desktop OpenGL, a compile error occurs, because
+a version number is too low. Lowering the version requirement avoids
+the compile errors and didn't seem to cause any problems so far.
+---
+ src/mesa/shader/slang/slang_compile.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/mesa/shader/slang/slang_compile.c b/src/mesa/shader/slang/slang_compile.c
+index ad86676..101623d 100644
+--- a/src/mesa/shader/slang/slang_compile.c
++++ b/src/mesa/shader/slang/slang_compile.c
+@@ -2571,7 +2571,7 @@ parse_code_unit(slang_parse_ctx * C, slang_code_unit * unit,
+ #if FEATURE_es2_glsl
+    o.allow_precision = GL_TRUE;
+ #else
+-   o.allow_precision = (C->version >= 120) ? GL_TRUE : GL_FALSE;
++   o.allow_precision = (C->version >= 110) ? GL_TRUE : GL_FALSE;
+ #endif
+    init_default_precision(&o, unit->type);
+