Bug 1015561 - WebGL change getParameter(STENCIL_[BACK]_REF) to return…

… correct masked values and update debug cached value test. r=jgilbert
dothq · Sep 26, 2014 · 4d2e052 · 4d2e052
1 parent d0ee26b
commit 4d2e052
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Showing 3 changed files with 66 additions and 6 deletions.
diff --git a/dom/canvas/WebGLContext.h b/dom/canvas/WebGLContext.h
@@ -836,6 +836,7 @@ class WebGLContext :
 public:
     void Disable(GLenum cap);
     void Enable(GLenum cap);
+    bool GetStencilBits(GLint* out_stencilBits);
     JS::Value GetParameter(JSContext* cx, GLenum pname, ErrorResult& rv);
     void GetParameter(JSContext* cx, GLenum pname,
                       JS::MutableHandle<JS::Value> retval, ErrorResult& rv) {

diff --git a/dom/canvas/WebGLContextState.cpp b/dom/canvas/WebGLContextState.cpp
@@ -70,6 +70,29 @@ StringValue(JSContext* cx, const char* chars, ErrorResult& rv)
     return JS::StringValue(str);
 }
 
+bool
+WebGLContext::GetStencilBits(GLint* out_stencilBits)
+{
+    *out_stencilBits = 0;
+    if (mBoundFramebuffer) {
+        if (mBoundFramebuffer->HasDepthStencilConflict()) {
+            // Error, we don't know which stencil buffer's bits to use
+            ErrorInvalidFramebufferOperation("getParameter: framebuffer has two stencil buffers bound");
+            return false;
+        }
+
+        if (mBoundFramebuffer->StencilAttachment().IsDefined() ||
+            mBoundFramebuffer->DepthStencilAttachment().IsDefined())
+        {
+            *out_stencilBits = 8;
+        }
+    } else if (mOptions.stencil) {
+        *out_stencilBits = 8;
+    }
+
+    return true;
+}
+
 JS::Value
 WebGLContext::GetParameter(JSContext* cx, GLenum pname, ErrorResult& rv)
 {
@@ -241,9 +264,26 @@ WebGLContext::GetParameter(JSContext* cx, GLenum pname, ErrorResult& rv)
             return JS::NumberValue(uint32_t(i));
         }
         // int
-        case LOCAL_GL_STENCIL_CLEAR_VALUE:
         case LOCAL_GL_STENCIL_REF:
-        case LOCAL_GL_STENCIL_BACK_REF:
+        case LOCAL_GL_STENCIL_BACK_REF: {
+            GLint stencilBits = 0;
+            if (!GetStencilBits(&stencilBits))
+                return JS::NullValue();
+
+            // Assuming stencils have 8 bits
+            const GLint stencilMask = (1 << stencilBits) - 1;
+
+            GLint refValue = 0;
+            gl->fGetIntegerv(pname, &refValue);
+
+            return JS::Int32Value(refValue & stencilMask);
+        }
+        case LOCAL_GL_STENCIL_BITS: {
+            GLint stencilBits = 0;
+            GetStencilBits(&stencilBits);
+            return JS::Int32Value(stencilBits);
+        }
+        case LOCAL_GL_STENCIL_CLEAR_VALUE:
         case LOCAL_GL_UNPACK_ALIGNMENT:
         case LOCAL_GL_PACK_ALIGNMENT:
         case LOCAL_GL_SUBPIXEL_BITS:
@@ -257,8 +297,7 @@ WebGLContext::GetParameter(JSContext* cx, GLenum pname, ErrorResult& rv)
         case LOCAL_GL_GREEN_BITS:
         case LOCAL_GL_BLUE_BITS:
         case LOCAL_GL_ALPHA_BITS:
-        case LOCAL_GL_DEPTH_BITS:
-        case LOCAL_GL_STENCIL_BITS: {
+        case LOCAL_GL_DEPTH_BITS: {
             GLint i = 0;
             gl->fGetIntegerv(pname, &i);
             return JS::Int32Value(i);

diff --git a/dom/canvas/WebGLContextUtils.cpp b/dom/canvas/WebGLContextUtils.cpp
@@ -705,6 +705,22 @@ AssertUintParamCorrect(gl::GLContext* gl, GLenum pname, GLuint shadow)
       MOZ_ASSERT(false, "Bad cached value.");
     }
 }
+
+void
+AssertMaskedUintParamCorrect(gl::GLContext* gl, GLenum pname, GLuint mask, GLuint shadow)
+{
+    GLuint val = 0;
+    gl->GetUIntegerv(pname, &val);
+
+    const GLuint valMasked = val & mask;
+    const GLuint shadowMasked = shadow & mask;
+
+    if (valMasked != shadowMasked) {
+      printf_stderr("Failed 0x%04x shadow: Cached 0x%x/%u, should be 0x%x/%u.\n",
+                    pname, shadowMasked, shadowMasked, valMasked, valMasked);
+      MOZ_ASSERT(false, "Bad cached value.");
+    }
+}
 #else
 void
 AssertUintParamCorrect(gl::GLContext*, GLenum, GLuint)
@@ -802,8 +818,12 @@ WebGLContext::AssertCachedState()
 
     AssertUintParamCorrect(gl, LOCAL_GL_STENCIL_CLEAR_VALUE, mStencilClearValue);
 
-    AssertUintParamCorrect(gl, LOCAL_GL_STENCIL_REF,      mStencilRefFront);
-    AssertUintParamCorrect(gl, LOCAL_GL_STENCIL_BACK_REF, mStencilRefBack);
+    GLint stencilBits = 0;
+    gl->fGetIntegerv(LOCAL_GL_STENCIL_BITS, &stencilBits);
+    const GLuint stencilRefMask = (1 << stencilBits) - 1;
+
+    AssertMaskedUintParamCorrect(gl, LOCAL_GL_STENCIL_REF,      stencilRefMask, mStencilRefFront);
+    AssertMaskedUintParamCorrect(gl, LOCAL_GL_STENCIL_BACK_REF, stencilRefMask, mStencilRefBack);
 
     AssertUintParamCorrect(gl, LOCAL_GL_STENCIL_VALUE_MASK,      mStencilValueMaskFront);
     AssertUintParamCorrect(gl, LOCAL_GL_STENCIL_BACK_VALUE_MASK, mStencilValueMaskBack);