[PATCH 4/8] wined3d: Fix draw calls when first render target is NULL.

[Józef Kucia]

In Direct3D 10+, the render target at index 0 can be set to NULL.

Signed-off-by: Józef Kucia <jkucia at codeweavers.com>
---

Also, a more complex logic may be needed for acquiring context
for no attachments draw calls.

There is a potential issue in the code: the assumption that the render
target is a texture, but it is a bug in the current code.

---
 dlls/wined3d/context.c | 53 ++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 38 insertions(+), 15 deletions(-)

diff --git a/dlls/wined3d/context.c b/dlls/wined3d/context.c
index 4282cfb94d01..534f05a9f0bd 100644
--- a/dlls/wined3d/context.c
+++ b/dlls/wined3d/context.c
@@ -3157,6 +3157,7 @@ void context_state_fb(struct wined3d_context *context, const struct wined3d_stat
 {
     DWORD rt_mask = find_draw_buffers_mask(context, state);
     const struct wined3d_fb_state *fb = state->fb;
+    DWORD color_location = 0;
     DWORD *cur_mask;
 
     if (wined3d_settings.offscreen_rendering_mode == ORM_FBO)
@@ -3173,18 +3174,20 @@ void context_state_fb(struct wined3d_context *context, const struct wined3d_stat
             memset(context->blit_targets, 0, sizeof(context->blit_targets));
             for (i = 0; i < context->gl_info->limits.buffers; ++i)
             {
-                if (fb->render_targets[i])
-                {
-                    context->blit_targets[i].gl_view = fb->render_targets[i]->gl_view;
-                    context->blit_targets[i].resource = fb->render_targets[i]->resource;
-                    context->blit_targets[i].sub_resource_idx = fb->render_targets[i]->sub_resource_idx;
-                    context->blit_targets[i].layer_count = fb->render_targets[i]->layer_count;
-                }
+                if (!fb->render_targets[i])
+                    continue;
+
+                context->blit_targets[i].gl_view = fb->render_targets[i]->gl_view;
+                context->blit_targets[i].resource = fb->render_targets[i]->resource;
+                context->blit_targets[i].sub_resource_idx = fb->render_targets[i]->sub_resource_idx;
+                context->blit_targets[i].layer_count = fb->render_targets[i]->layer_count;
+
+                if (!color_location)
+                    color_location = fb->render_targets[i]->resource->draw_binding;
             }
             context_apply_fbo_state(context, GL_FRAMEBUFFER, context->blit_targets,
                     wined3d_rendertarget_view_get_surface(fb->depth_stencil),
-                    fb->render_targets[0] ? fb->render_targets[0]->resource->draw_binding : 0,
-                    fb->depth_stencil ? fb->depth_stencil->resource->draw_binding : 0);
+                    color_location, fb->depth_stencil ? fb->depth_stencil->resource->draw_binding : 0);
         }
     }
 
@@ -4774,6 +4777,31 @@ static GLenum gl_tfb_primitive_type_from_d3d(enum wined3d_primitive_type primiti
     }
 }
 
+static struct wined3d_context *context_acquire_for_draw_call(const struct wined3d_device *device,
+        const struct wined3d_fb_state *fb)
+{
+    struct wined3d_texture *texture = NULL;
+    struct wined3d_rendertarget_view *rtv;
+    unsigned int sub_resource_idx = 0;
+    unsigned int i;
+
+    for (i = 0; i < ARRAY_SIZE(fb->render_targets); ++i)
+    {
+        if ((rtv = fb->render_targets[i]))
+            break;
+    }
+    if (!rtv)
+        rtv = fb->depth_stencil;
+
+    if (rtv)
+    {
+        texture = wined3d_texture_from_resource(rtv->resource);
+        sub_resource_idx = rtv->sub_resource_idx;
+    }
+
+    return context_acquire(device, texture, sub_resource_idx);
+}
+
 /* Routine common to the draw primitive and draw indexed primitive routines */
 void draw_primitive(struct wined3d_device *device, const struct wined3d_state *state,
         const struct wined3d_draw_parameters *parameters)
@@ -4792,12 +4820,7 @@ void draw_primitive(struct wined3d_device *device, const struct wined3d_state *s
     if (!parameters->indirect && !parameters->u.direct.index_count)
         return;
 
-    if (!(rtv = fb->render_targets[0]))
-        rtv = fb->depth_stencil;
-    if (rtv)
-        context = context_acquire(device, wined3d_texture_from_resource(rtv->resource), rtv->sub_resource_idx);
-    else
-        context = context_acquire(device, NULL, 0);
+    context = context_acquire_for_draw_call(device, fb);
     if (!context->valid)
     {
         context_release(context);
-- 
2.16.1