[PATCH 3/5] wined3d: Enforce a stable texture units mapping.

[Matteo Bruni]

The GLSL shader backend hardcodes the sampler uniforms at program link
time, it can't handle a change in the mapping between draws with the
same shader program.

Signed-off-by: Matteo Bruni <mbruni at codeweavers.com>
---
This should fix the low water bug in World of Warships (bug 39347) on OS X.

 dlls/wined3d/context.c     | 37 +++++++++++++++++--------------------
 dlls/wined3d/glsl_shader.c |  9 ++-------
 2 files changed, 19 insertions(+), 27 deletions(-)

diff --git a/dlls/wined3d/context.c b/dlls/wined3d/context.c
index 1baf084..daa5f1c 100644
--- a/dlls/wined3d/context.c
+++ b/dlls/wined3d/context.c
@@ -2554,6 +2554,7 @@ static void context_map_stage(struct wined3d_context *context, DWORD stage, DWOR
     DWORD i = context->rev_tex_unit_map[unit];
     DWORD j = context->tex_unit_map[stage];
 
+    TRACE("Mapping stage %u to unit %u.\n", stage, unit);
     context->tex_unit_map[stage] = unit;
     if (i != WINED3D_UNMAPPED_STAGE && i != stage)
         context->tex_unit_map[i] = WINED3D_UNMAPPED_STAGE;
@@ -2700,8 +2701,7 @@ static void context_map_psamplers(struct wined3d_context *context, const struct
 }
 
 static BOOL context_unit_free_for_vs(const struct wined3d_context *context,
-        const struct wined3d_shader_resource_info *ps_resource_info,
-        const struct wined3d_shader_resource_info *vs_resource_info, DWORD unit)
+        const struct wined3d_shader_resource_info *ps_resource_info, DWORD unit)
 {
     DWORD current_mapping = context->rev_tex_unit_map[unit];
 
@@ -2723,8 +2723,7 @@ static BOOL context_unit_free_for_vs(const struct wined3d_context *context,
         return !ps_resource_info[current_mapping].type;
     }
 
-    /* Used by a vertex sampler */
-    return !vs_resource_info[current_mapping - MAX_FRAGMENT_SAMPLERS].type;
+    return TRUE;
 }
 
 static void context_map_vsamplers(struct wined3d_context *context, BOOL ps, const struct wined3d_state *state)
@@ -2750,18 +2749,15 @@ static void context_map_vsamplers(struct wined3d_context *context, BOOL ps, cons
         DWORD vsampler_idx = i + MAX_FRAGMENT_SAMPLERS;
         if (vs_resource_info[i].type)
         {
-            if (context->tex_unit_map[vsampler_idx] != WINED3D_UNMAPPED_STAGE)
-            {
-                /* Already mapped somewhere */
-                continue;
-            }
-
             while (start >= 0)
             {
-                if (context_unit_free_for_vs(context, ps_resource_info, vs_resource_info, start))
+                if (context_unit_free_for_vs(context, ps_resource_info, start))
                 {
-                    context_map_stage(context, vsampler_idx, start);
-                    context_invalidate_state(context, STATE_SAMPLER(vsampler_idx));
+                    if (context->tex_unit_map[vsampler_idx] != start)
+                    {
+                        context_map_stage(context, vsampler_idx, start);
+                        context_invalidate_state(context, STATE_SAMPLER(vsampler_idx));
+                    }
 
                     --start;
                     break;
@@ -2769,6 +2765,8 @@ static void context_map_vsamplers(struct wined3d_context *context, BOOL ps, cons
 
                 --start;
             }
+            if (context->tex_unit_map[vsampler_idx] == WINED3D_UNMAPPED_STAGE)
+                WARN("Couldn't find a free texture unit for vertex sampler %u.\n", i);
         }
     }
 }
@@ -2777,13 +2775,12 @@ static void context_update_tex_unit_map(struct wined3d_context *context, const s
 {
     BOOL vs = use_vs(state);
     BOOL ps = use_ps(state);
-    /*
-     * Rules are:
-     * -> Pixel shaders need a 1:1 map. In theory the shader input could be mapped too, but
-     * that would be really messy and require shader recompilation
-     * -> When the mapping of a stage is changed, sampler and ALL texture stage states have
-     * to be reset. Because of that try to work with a 1:1 mapping as much as possible
-     */
+
+    /* Try to go for a 1:1 mapping of the samplers when possible. Pixel shaders
+     * need a 1:1 map at the moment.
+     * When the mapping of a stage is changed, sampler and ALL texture stage
+     * states have to be reset. */
+
     if (ps)
         context_map_psamplers(context, state);
     else
diff --git a/dlls/wined3d/glsl_shader.c b/dlls/wined3d/glsl_shader.c
index 44e7090..abfaef8 100644
--- a/dlls/wined3d/glsl_shader.c
+++ b/dlls/wined3d/glsl_shader.c
@@ -7095,13 +7095,8 @@ static void set_glsl_shader_program(const struct wined3d_context *context, const
     GL_EXTCALL(glUseProgram(program_id));
     checkGLcall("glUseProgram");
 
-    /* Load the vertex and pixel samplers now. The function that finds the mappings makes sure
-     * that it stays the same for each vertexshader-pixelshader pair(=linked glsl program). If
-     * a pshader with fixed function pipeline is used there are no vertex samplers, and if a
-     * vertex shader with fixed function pixel processing is used we make sure that the card
-     * supports enough samplers to allow the max number of vertex samplers with all possible
-     * fixed function fragment processing setups. So once the program is linked these samplers
-     * won't change. */
+    /* Texture unit mapping is set up to be the same each time the shader
+     * program is used so we can hardcode the sampler uniform values. */
     shader_glsl_load_samplers(gl_info, priv, context->tex_unit_map, program_id);
 
     entry->constant_update_mask = 0;
-- 
2.4.10