wined3d: Avoid reading uninitialized texcoord varyings in FFP replacement fragment shaders.

Signed-off-by: Matteo Bruni <mbruni@codeweavers.com>
Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>

dlls/wined3d/glsl_shader.c

@@ -6295,20 +6295,35 @@ static GLuint shader_glsl_generate_ffp_fragment_shader(struct shader_glsl_priv *
 
     if (legacy_context)
     {
+        shader_addline(buffer, "vec4 ffp_texcoord[%u];\n", MAX_TEXTURES);
         shader_addline(buffer, "float ffp_varying_fogcoord;\n");
     }
     else
     {
+        shader_addline(buffer, "vec4 ffp_texcoord[%u];\n", MAX_TEXTURES);
         declare_in_varying(gl_info, buffer, FALSE, "float ffp_varying_fogcoord;\n");
     }
 
     shader_addline(buffer, "void main()\n{\n");
 
+    for (stage = 0; stage < MAX_TEXTURES; ++stage)
+    {
+        if (tex_map & (1u << stage))
+        {
+            if (settings->pointsprite)
+                shader_addline(buffer, "ffp_texcoord[%u] = vec4(gl_PointCoord.xy, 0.0, 0.0);\n", stage);
+            else if (settings->texcoords_initialized & (1u << stage))
+                shader_addline(buffer, "ffp_texcoord[%u] = gl_TexCoord[%u];\n", stage, stage);
+            else
+                shader_addline(buffer, "ffp_texcoord[%u] = vec4(0.0);\n", stage);
+        }
+    }
+
     if (legacy_context && settings->fog != WINED3D_FFP_PS_FOG_OFF)
         shader_addline(buffer, "ffp_varying_fogcoord = gl_FogFragCoord;\n");
 
     if (lowest_disabled_stage < 7 && settings->emul_clipplanes)
-        shader_addline(buffer, "if (any(lessThan(gl_TexCoord[7], vec4(0.0)))) discard;\n");
+        shader_addline(buffer, "if (any(lessThan(ffp_texcoord[7], vec4(0.0)))) discard;\n");
 
     /* Generate texture sampling instructions) */
     for (stage = 0; stage < MAX_TEXTURES && settings->op[stage].cop != WINED3D_TOP_DISABLE; ++stage)
@@ -6409,20 +6424,20 @@ static GLuint shader_glsl_generate_ffp_fragment_shader(struct shader_glsl_priv *
             {
                 if (settings->op[stage].projected == proj_count4)
                 {
-                    shader_addline(buffer, "ret.xy = (ret.xy * gl_TexCoord[%u].w) + gl_TexCoord[%u].xy;\n",
+                    shader_addline(buffer, "ret.xy = (ret.xy * ffp_texcoord[%u].w) + ffp_texcoord[%u].xy;\n",
                             stage, stage);
-                    shader_addline(buffer, "ret.zw = gl_TexCoord[%u].ww;\n", stage);
+                    shader_addline(buffer, "ret.zw = ffp_texcoord[%u].ww;\n", stage);
                 }
                 else
                 {
-                    shader_addline(buffer, "ret.xy = (ret.xy * gl_TexCoord[%u].z) + gl_TexCoord[%u].xy;\n",
+                    shader_addline(buffer, "ret.xy = (ret.xy * ffp_texcoord[%u].z) + ffp_texcoord[%u].xy;\n",
                             stage, stage);
-                    shader_addline(buffer, "ret.zw = gl_TexCoord[%u].zz;\n", stage);
+                    shader_addline(buffer, "ret.zw = ffp_texcoord[%u].zz;\n", stage);
                 }
             }
             else
             {
-                shader_addline(buffer, "ret = gl_TexCoord[%u] + ret.xyxy;\n", stage);
+                shader_addline(buffer, "ret = ffp_texcoord[%u] + ret.xyxy;\n", stage);
             }
 
             shader_addline(buffer, "tex%u = %s(ps_sampler%u, ret.%s);\n",
@@ -6434,12 +6449,12 @@ static GLuint shader_glsl_generate_ffp_fragment_shader(struct shader_glsl_priv *
         }
         else if (settings->op[stage].projected == proj_count3)
         {
-            shader_addline(buffer, "tex%u = %s(ps_sampler%u, gl_TexCoord[%u].xyz);\n",
+            shader_addline(buffer, "tex%u = %s(ps_sampler%u, ffp_texcoord[%u].xyz);\n",
                     stage, texture_function, stage, stage);
         }
         else
         {
-            shader_addline(buffer, "tex%u = %s(ps_sampler%u, gl_TexCoord[%u].%s);\n",
+            shader_addline(buffer, "tex%u = %s(ps_sampler%u, ffp_texcoord[%u].%s);\n",
                     stage, texture_function, stage, stage, coord_mask);
         }
 
@@ -8391,10 +8406,22 @@ static void glsl_fragment_pipe_fog(struct wined3d_context *context,
 static void glsl_fragment_pipe_vdecl(struct wined3d_context *context,
         const struct wined3d_state *state, DWORD state_id)
 {
+    /* Because of settings->texcoords_initialized. */
+    if (!use_ps(state) && context->gl_info->limits.glsl_varyings < wined3d_max_compat_varyings(context->gl_info))
+        context->shader_update_mask |= 1u << WINED3D_SHADER_TYPE_PIXEL;
+
     if (!isStateDirty(context, STATE_RENDER(WINED3D_RS_FOGENABLE)))
         glsl_fragment_pipe_fog(context, state, state_id);
 }
 
+static void glsl_fragment_pipe_vs(struct wined3d_context *context,
+        const struct wined3d_state *state, DWORD state_id)
+{
+    /* Because of settings->texcoords_initialized. */
+    if (!use_ps(state) && context->gl_info->limits.glsl_varyings < wined3d_max_compat_varyings(context->gl_info))
+        context->shader_update_mask |= 1u << WINED3D_SHADER_TYPE_PIXEL;
+}
+
 static void glsl_fragment_pipe_tex_transform(struct wined3d_context *context,
         const struct wined3d_state *state, DWORD state_id)
 {
@@ -8447,6 +8474,7 @@ static void glsl_fragment_pipe_color_key(struct wined3d_context *context,
 static const struct StateEntryTemplate glsl_fragment_pipe_state_template[] =
 {
     {STATE_VDECL,                                               {STATE_VDECL,                                                glsl_fragment_pipe_vdecl               }, WINED3D_GL_EXT_NONE },
+    {STATE_SHADER(WINED3D_SHADER_TYPE_VERTEX),                  {STATE_SHADER(WINED3D_SHADER_TYPE_VERTEX),                   glsl_fragment_pipe_vs                  }, WINED3D_GL_EXT_NONE },
     {STATE_RENDER(WINED3D_RS_TEXTUREFACTOR),                    {STATE_RENDER(WINED3D_RS_TEXTUREFACTOR),                     glsl_fragment_pipe_invalidate_constants}, WINED3D_GL_EXT_NONE },
     {STATE_TEXTURESTAGE(0, WINED3D_TSS_COLOR_OP),               {STATE_SHADER(WINED3D_SHADER_TYPE_PIXEL),                    NULL                                   }, WINED3D_GL_EXT_NONE },
     {STATE_TEXTURESTAGE(0, WINED3D_TSS_COLOR_ARG1),             {STATE_SHADER(WINED3D_SHADER_TYPE_PIXEL),                    NULL                                   }, WINED3D_GL_EXT_NONE },

dlls/wined3d/utils.c

@@ -4629,6 +4629,43 @@ void gen_ffp_frag_op(const struct wined3d_context *context, const struct wined3d
         settings->color_key_enabled = 1;
     else
         settings->color_key_enabled = 0;
+
+    /* texcoords_initialized is set to meaningful values only when GL doesn't
+     * support enough varyings to always pass around all the possible texture
+     * coordinates.
+     * This is used to avoid reading a varying not written by the vertex shader.
+     * Reading uninitialized varyings on core profile contexts results in an
+     * error while with builtin varyings on legacy contexts you get undefined
+     * behavior. */
+    if (d3d_info->limits.varying_count
+            && d3d_info->limits.varying_count < wined3d_max_compat_varyings(gl_info))
+    {
+        settings->texcoords_initialized = 0;
+        for (i = 0; i < MAX_TEXTURES; ++i)
+        {
+            if (use_vs(state))
+            {
+                if (state->shader[WINED3D_SHADER_TYPE_VERTEX]->reg_maps.output_registers & (1u << i))
+                    settings->texcoords_initialized |= 1u << i;
+            }
+            else
+            {
+                const struct wined3d_stream_info *si = &context->stream_info;
+                unsigned int coord_idx = state->texture_states[i][WINED3D_TSS_TEXCOORD_INDEX];
+                if ((state->texture_states[i][WINED3D_TSS_TEXCOORD_INDEX] >> WINED3D_FFP_TCI_SHIFT)
+                        & WINED3D_FFP_TCI_MASK
+                        || (coord_idx < MAX_TEXTURES && (si->use_map & (1u << (WINED3D_FFP_TEXCOORD0 + coord_idx)))))
+                    settings->texcoords_initialized |= 1u << i;
+            }
+        }
+    }
+    else
+    {
+        settings->texcoords_initialized = (1u << MAX_TEXTURES) - 1;
+    }
+
+    settings->pointsprite = state->render_states[WINED3D_RS_POINTSPRITEENABLE]
+            && state->gl_primitive_type == GL_POINTS;
 }
 
 const struct ffp_frag_desc *find_ffp_frag_shader(const struct wine_rb_tree *fragment_shaders,

dlls/wined3d/wined3d_private.h

@@ -1865,8 +1865,10 @@ struct ffp_frag_settings
     enum wined3d_ffp_ps_fog_mode fog;
     unsigned char sRGB_write;
     unsigned char emul_clipplanes;
-    unsigned char color_key_enabled;
+    unsigned char texcoords_initialized;
-    unsigned char padding;
+    unsigned char color_key_enabled : 1;
+    unsigned char pointsprite : 1;
+    unsigned char padding : 6;
 };
 
 struct ffp_frag_desc