Relax multi-view end-point validation on detach

extensions/ANGLE_multiview.txt

@@ -257,11 +257,12 @@ Additions to Chapter 4 of the OpenGL ES 3.0 Specification
         and does not name an existing texture object of type TEXTURE_2D_ARRAY.
         An INVALID_OPERATION error is generated if texture is not zero,
         and names a texture with a compressed texture format.
-        An INVALID_VALUE error is generated if baseViewIndex+numViews is
-        greater than GL_MAX_ARRAY_TEXTURE_LAYERS.
-        An INVALID_VALUE error is generated if numViews is less than 1
-        or greater than MAX_VIEWS_ANGLE.
-        An INVALID_VALUE error is generated if baseViewIndex is less than 0.
+        An INVALID_VALUE error is generated if texture is not zero, and
+        baseViewIndex+numViews is greater than GL_MAX_ARRAY_TEXTURE_LAYERS.
+        An INVALID_VALUE error is generated if texture is not zero, and
+        numViews is less than 1 or greater than MAX_VIEWS_ANGLE.
+        An INVALID_VALUE error is generated if texture is not zero, and
+        baseViewIndex is less than 0.
 
     The command
 
@@ -331,10 +332,10 @@ Additions to Chapter 4 of the OpenGL ES 3.0 Specification
         and does not name an existing texture object of type TEXTURE_2D.
         An INVALID_OPERATION error is generated if texture is not zero,
         and names a texture with a compressed texture format.
-        An INVALID_VALUE error is generated if numViews is less than 1
-        or greater than MAX_VIEWS_ANGLE.
-        An INVALID_VALUE error is generated if viewportOffsets contains
-        negative values.
+        An INVALID_VALUE error is generated if texture is not zero, and
+        numViews is less than 1 or greater than MAX_VIEWS_ANGLE.
+        An INVALID_VALUE error is generated if texture is not zero, and
+        any of the first numViews * 2 values in viewportOffsets is negative.
 
     Having overlapping scissor rectangles after viewport offsets are
     applied causes undefined behavior.

src/libANGLE/validationES3.cpp

@@ -45,7 +45,7 @@ bool ValidateFramebufferTextureMultiviewBaseANGLE(Context *context,
         return false;
     }
 
-    if (numViews < 1)
+    if (texture != 0 && numViews < 1)
     {
         context->handleError(InvalidValue() << "numViews cannot be less than 1.");
         return false;
@@ -2727,14 +2727,14 @@ bool ValidateFramebufferTextureMultiviewLayeredANGLE(Context *context,
         return false;
     }
 
-    if (baseViewIndex < 0)
-    {
-        context->handleError(InvalidValue() << "baseViewIndex cannot be less than 0.");
-        return false;
-    }
-
     if (texture != 0)
     {
+        if (baseViewIndex < 0)
+        {
+            context->handleError(InvalidValue() << "baseViewIndex cannot be less than 0.");
+            return false;
+        }
+
         Texture *tex = context->getTexture(texture);
         ASSERT(tex);
 
@@ -2781,19 +2781,19 @@ bool ValidateFramebufferTextureMultiviewSideBySideANGLE(Context *context,
         return false;
     }
 
-    const GLsizei numViewportOffsetValues = numViews * 2;
-    for (GLsizei i = 0; i < numViewportOffsetValues; ++i)
+    if (texture != 0)
     {
-        if (viewportOffsets[i] < 0)
+        const GLsizei numViewportOffsetValues = numViews * 2;
+        for (GLsizei i = 0; i < numViewportOffsetValues; ++i)
         {
-            context->handleError(InvalidValue()
-                                 << "viewportOffsets cannot contain negative values.");
-            return false;
+            if (viewportOffsets[i] < 0)
+            {
+                context->handleError(InvalidValue()
+                                     << "viewportOffsets cannot contain negative values.");
+                return false;
+            }
         }
-    }
 
-    if (texture != 0)
-    {
         Texture *tex = context->getTexture(texture);
         ASSERT(tex);
 

src/tests/gl_tests/FramebufferMultiviewTest.cpp

@@ -1294,6 +1294,39 @@ TEST_P(FramebufferMultiviewLayeredClearTest, ScissoredClearBufferfi)
     EXPECT_EQ(GLColor::red, getLayerColor(3, GL_COLOR_ATTACHMENT0, 0, 1));
 }
 
+// Test that detaching an attachment does not generate an error whenever the multi-view related
+// arguments are invalid.
+TEST_P(FramebufferMultiviewTest, InvalidMultiviewArgumentsOnDetach)
+{
+    if (!requestMultiviewExtension())
+    {
+        return;
+    }
+
+    GLFramebuffer fbo;
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+    // Invalid base view index.
+    glFramebufferTextureMultiviewLayeredANGLE(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, 0, 0, -1, 1);
+    EXPECT_GL_NO_ERROR();
+
+    // Invalid number of views.
+    glFramebufferTextureMultiviewLayeredANGLE(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, 0, 0, 0, 0);
+    EXPECT_GL_NO_ERROR();
+
+    // Invalid number of views.
+    const GLint kValidViewportOffsets[2] = {0, 0};
+    glFramebufferTextureMultiviewSideBySideANGLE(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, 0, 0, 0,
+                                                 kValidViewportOffsets);
+    EXPECT_GL_NO_ERROR();
+
+    // Invalid viewport offsets.
+    const GLint kInvalidViewportOffsets[2] = {-1, -1};
+    glFramebufferTextureMultiviewSideBySideANGLE(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, 0, 0, 1,
+                                                 kInvalidViewportOffsets);
+    EXPECT_GL_NO_ERROR();
+}
+
 ANGLE_INSTANTIATE_TEST(FramebufferMultiviewTest, ES3_OPENGL());
 ANGLE_INSTANTIATE_TEST(FramebufferMultiviewSideBySideClearTest, ES3_OPENGL(), ES3_D3D11());
 ANGLE_INSTANTIATE_TEST(FramebufferMultiviewLayeredClearTest, ES3_OPENGL(), ES3_D3D11());
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