wined3d: Maintain default sampler per device.

dlls/wined3d/device.c

@@ -773,6 +773,49 @@ static void destroy_dummy_textures(struct wined3d_device *device, const struct w
     memset(device->dummy_texture_2d, 0, count * sizeof(*device->dummy_texture_2d));
 }
 
+/* Context activation is done by the caller. */
+static void create_default_sampler(struct wined3d_device *device)
+{
+    const struct wined3d_gl_info *gl_info = &device->adapter->gl_info;
+
+    /*
+     * In SM4+ shaders there is a separation between resources and samplers. Some of shader
+     * instructions allow to access resources without using samplers.
+     * In GLSL resources are always accessed through sampler or image variables. The default
+     * sampler object is used to emulate the direct resource access when there is no sampler state
+     * to use.
+     */
+
+    if (gl_info->supported[ARB_SAMPLER_OBJECTS])
+    {
+        GL_EXTCALL(glGenSamplers(1, &device->default_sampler));
+        checkGLcall("glGenSamplers");
+        if (gl_info->supported[EXT_TEXTURE_SRGB_DECODE])
+        {
+            GL_EXTCALL(glSamplerParameteri(device->default_sampler, GL_TEXTURE_SRGB_DECODE_EXT, GL_SKIP_DECODE_EXT));
+            checkGLcall("glSamplerParamteri");
+        }
+    }
+    else
+    {
+        device->default_sampler = 0;
+    }
+}
+
+/* Context activation is done by the caller. */
+static void destroy_default_sampler(struct wined3d_device *device)
+{
+    const struct wined3d_gl_info *gl_info = &device->adapter->gl_info;
+
+    if (gl_info->supported[ARB_SAMPLER_OBJECTS])
+    {
+        GL_EXTCALL(glDeleteSamplers(1, &device->default_sampler));
+        checkGLcall("glDeleteSamplers");
+    }
+
+    device->default_sampler = 0;
+}
+
 static LONG fullscreen_style(LONG style)
 {
     /* Make sure the window is managed, otherwise we won't get keyboard input. */
@@ -972,6 +1015,7 @@ HRESULT CDECL wined3d_device_init_3d(struct wined3d_device *device,
             surface_from_resource(wined3d_texture_get_sub_resource(swapchain->front_buffer, 0)));
 
     create_dummy_textures(device, context);
+    create_default_sampler(device);
 
     device->contexts[0]->last_was_rhw = 0;
 
@@ -1119,6 +1163,7 @@ HRESULT CDECL wined3d_device_uninit_3d(struct wined3d_device *device)
     device->blitter->free_private(device);
     device->shader_backend->shader_free_private(device);
     destroy_dummy_textures(device, gl_info);
+    destroy_default_sampler(device);
 
     /* Release the context again as soon as possible. In particular,
      * releasing the render target views below may release the last reference

dlls/wined3d/wined3d_private.h

@@ -2128,6 +2128,9 @@ struct wined3d_device
     UINT dummy_texture_3d[MAX_COMBINED_SAMPLERS];
     UINT dummy_texture_cube[MAX_COMBINED_SAMPLERS];
 
+    /* Default sampler used to emulate the direct resource access without using wined3d_sampler */
+    GLuint default_sampler;
+
     /* Command stream */
     struct wined3d_cs *cs;