hlsl: Emit attributes for POSITION1 and above.

Also, add an assert for the case where a buggy VS is missing outputs its PS needs (the shader will fail to compile anyway and produce a mystery crash later, so this is an improvement)
icculus · Jun 16, 2021 · ae7c0f6 · ae7c0f6
1 parent c9037d9
commit ae7c0f6
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Showing 2 changed files with 35 additions and 16 deletions.
diff --git a/mojoshader_d3d11.c b/mojoshader_d3d11.c
@@ -452,11 +452,13 @@ static char *rewritePixelShader(MOJOSHADER_d3d11Shader *vshader,
     const char *pvarname, *vvarname;
     for (i = 0; i < ppd->attribute_count; i++)
     {
+        int found_matching_vs_output_for_ps_input = 0;
         for (j = 0; j < vpd->output_count; j++)
         {
             if (ppd->attributes[i].usage == vpd->outputs[j].usage &&
                 ppd->attributes[i].index == vpd->outputs[j].index)
             {
+                found_matching_vs_output_for_ps_input = 1;
                 pvarname = ppd->attributes[i].name;
                 vvarname = vpd->outputs[j].name;
                 if (strcmp(pvarname, vvarname) != 0)
@@ -466,6 +468,7 @@ static char *rewritePixelShader(MOJOSHADER_d3d11Shader *vshader,
                      vpd->outputs[j].usage == MOJOSHADER_USAGE_POSITION &&
                      vpd->outputs[j].index == 0)
             {
+                found_matching_vs_output_for_ps_input = 1;
                 pvarname = ppd->attributes[i].name;
                 vvarname = vpd->outputs[j].name;
                 if (strcmp(pvarname, vvarname) != 0)
@@ -475,6 +478,14 @@ static char *rewritePixelShader(MOJOSHADER_d3d11Shader *vshader,
 
         if (strcmp(ppd->attributes[i].name, "vFace") == 0)
             vfaceidx = i;
+
+        // A vertex shader that doesn't properly initialize all its outputs
+        //  can produce a situation where vpd->outputs is missing a matching
+        //  entry for the PS's inputs, even though fxc will happily compile
+        //  both shaders together as a technique in FX mode
+        // I don't know how to fix this yet, but a workaround is to
+        //  correct your shader to zero-initialize all its outputs -kg
+        assert(found_matching_vs_output_for_ps_input);
     } // for
 
     // Special handling for VFACE

diff --git a/profiles/mojoshader_profile_hlsl.c b/profiles/mojoshader_profile_hlsl.c
@@ -1048,23 +1048,31 @@ void emit_HLSL_attribute(Context *ctx, RegisterType regtype, int regnum,
 
             else
             {
-                if (usage == MOJOSHADER_USAGE_TEXCOORD)
+                switch (usage)
                 {
-                    // ps_1_1 does a different hack for this attribute.
-                    //  Refer to emit_HLSL_global()'s REG_TYPE_ADDRESS code.
-                    if (!shader_version_atleast(ctx, 1, 4))
-                        skipreference = 1;
-                    output_line(ctx, "float4 m_%s : TEXCOORD%d;", var, index);
-                } // if
-
-                else if (usage == MOJOSHADER_USAGE_COLOR)
-                    output_line(ctx, "float4 m_%s : COLOR%d;", var, index);
-
-                else if (usage == MOJOSHADER_USAGE_FOG)
-                    output_line(ctx, "float m_%s : FOG;", var);
-
-                else if (usage == MOJOSHADER_USAGE_NORMAL)
-                    output_line(ctx, "float4 m_%s : NORMAL;", var);
+                    case MOJOSHADER_USAGE_TEXCOORD:
+                        // ps_1_1 does a different hack for this attribute.
+                        //  Refer to emit_HLSL_global()'s REG_TYPE_ADDRESS code.
+                        if (!shader_version_atleast(ctx, 1, 4))
+                            skipreference = 1;
+                        output_line(ctx, "float4 m_%s : TEXCOORD%d;", var, index);
+                        break;
+                    case MOJOSHADER_USAGE_COLOR:
+                        output_line(ctx, "float4 m_%s : COLOR%d;", var, index);
+                        break;
+                    case MOJOSHADER_USAGE_FOG:
+                        output_line(ctx, "float m_%s : FOG;", var);
+                        break;
+                    case MOJOSHADER_USAGE_NORMAL:
+                        output_line(ctx, "float4 m_%s : NORMAL;", var);
+                        break;
+                    case MOJOSHADER_USAGE_POSITION:
+                        output_line(ctx, "float4 m_%s : POSITION%d;", var, index);
+                        break;
+                    default:
+                        fail(ctx, "BUG: unhandled pixel shader input");
+                        break;
+                } // switch
             } // else
 
             pop_output(ctx);