Improve precision handling in tests with FragCoord

The tests for gl_FragCoord are not accurate enough, these tests pass
event for invalid driver. The comparison is made on RGBA8 surfaces,
it is not accurate enough for the tests.

The fix makes comparison more precise for the tests.

Modified tests:
dEQP-VK.glsl.builtin_var.simple.fragcoord_xyz
dEQP-VK.glsl.builtin_var.simple.fragcoord_w

Components: Vulkan
VK-GL-CTS issue: 77

Change-Id: I34ba77e696524215468202ef3fe77d1284e3e3df

diff --git a/external/vulkancts/modules/vulkan/shaderrender/vktShaderRenderBuiltinVarTests.cpp b/external/vulkancts/modules/vulkan/shaderrender/vktShaderRenderBuiltinVarTests.cpp
index 15326d0..8364db9 100644 (file)
--- a/external/vulkancts/modules/vulkan/shaderrender/vktShaderRenderBuiltinVarTests.cpp
+++ b/external/vulkancts/modules/vulkan/shaderrender/vktShaderRenderBuiltinVarTests.cpp
@@ -264,6 +264,7 @@ public:
 BuiltinGlFragCoordXYZCaseInstance::BuiltinGlFragCoordXYZCaseInstance (Context& context)
        : ShaderRenderCaseInstance      (context)
 {
+       m_colorFormat = VK_FORMAT_R16G16B16A16_UNORM;
 }
 
 TestStatus BuiltinGlFragCoordXYZCaseInstance::iterate (void)
@@ -272,10 +273,7 @@ TestStatus BuiltinGlFragCoordXYZCaseInstance::iterate (void)
        const int               width                   = viewportSize.x();
        const int               height                  = viewportSize.y();
        const tcu::Vec3 scale                   (1.f / float(width), 1.f / float(height), 1.0f);
-       const tcu::RGBA threshold               (2, 2, 2, 2);
-       Surface                 resImage                (width, height);
-       Surface                 refImage                (width, height);
-       bool                    compareOk               = false;
+       const float             precision               = 0.00001f;
        const deUint16  indices[6]              =
        {
                2, 1, 3,
@@ -286,30 +284,28 @@ TestStatus BuiltinGlFragCoordXYZCaseInstance::iterate (void)
        addUniform(0, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, scale);
 
        render(4, 2, indices);
-       copy(resImage.getAccess(), getResultImage().getAccess());
 
        // Reference image
-       for (int y = 0; y < refImage.getHeight(); y++)
+       for (int y = 0; y < height; y++)
        {
-               for (int x = 0; x < refImage.getWidth(); x++)
+               for (int x = 0; x < width; x++)
                {
-                       const float     xf                      = (float(x)+.5f) / float(refImage.getWidth());
-                       const float     yf                      = (float(refImage.getHeight()-y-1)+.5f) / float(refImage.getHeight());
+                       const float     xf                      = (float(x) + .5f) / float(width);
+                       const float     yf                      = (float(height - y - 1) + .5f) / float(height);
                        const float     z                       = (xf + yf) / 2.0f;
-                       const Vec3      fragCoord       (float(x)+.5f, float(y)+.5f, z);
+                       const Vec3      fragCoord       (float(x) + .5f, float(y) + .5f, z);
                        const Vec3      scaledFC        = fragCoord*scale;
                        const Vec4      color           (scaledFC.x(), scaledFC.y(), scaledFC.z(), 1.0f);
+                       const Vec4      resultColor     = getResultImage().getAccess().getPixel(x, y);
 
-                       refImage.setPixel(x, y, RGBA(color));
+                       if (de::abs(color.x() - resultColor.x()) > precision ||
+                               de::abs(color.y() - resultColor.y()) > precision ||
+                               de::abs(color.z() - resultColor.z()) > precision)
+                       return TestStatus::fail("Image mismatch");
                }
        }
 
-       compareOk = pixelThresholdCompare(m_context.getTestContext().getLog(), "Result", "Image comparison result", refImage, resImage, threshold, COMPARE_LOG_RESULT);
-
-       if (compareOk)
-               return TestStatus::pass("Result image matches reference");
-       else
-               return TestStatus::fail("Image mismatch");
+       return TestStatus::pass("Result image matches reference");
 }
 
 void BuiltinGlFragCoordXYZCaseInstance::setupDefaultInputs (void)
@@ -396,6 +392,7 @@ BuiltinGlFragCoordWCaseInstance::BuiltinGlFragCoordWCaseInstance (Context& conte
        : ShaderRenderCaseInstance      (context)
        , m_w                                           (1.7f, 2.0f, 1.2f, 1.0f)
 {
+       m_colorFormat = VK_FORMAT_R16G16B16A16_UNORM;
 }
 
 TestStatus BuiltinGlFragCoordWCaseInstance::iterate (void)
@@ -403,10 +400,7 @@ TestStatus BuiltinGlFragCoordWCaseInstance::iterate (void)
        const UVec2             viewportSize    = getViewportSize();
        const int               width                   = viewportSize.x();
        const int               height                  = viewportSize.y();
-       const tcu::RGBA threshold               (2, 2, 2, 2);
-       Surface                 resImage                (width, height);
-       Surface                 refImage                (width, height);
-       bool                    compareOk               = false;
+       const float             precision               = 0.00001f;
        const deUint16  indices[6]              =
        {
                2, 1, 3,
@@ -415,30 +409,28 @@ TestStatus BuiltinGlFragCoordWCaseInstance::iterate (void)
 
        setup();
        render(4, 2, indices);
-       copy(resImage.getAccess(), getResultImage().getAccess());
 
        // Reference image
-       for (int y = 0; y < refImage.getHeight(); y++)
+       for (int y = 0; y < height; y++)
        {
-               for (int x = 0; x < refImage.getWidth(); x++)
+               for (int x = 0; x < width; x++)
                {
-                       const float     xf                      = (float(x)+.5f) / float(refImage.getWidth());
-                       const float     yf                      = (float(refImage.getHeight()-y-1)+.5f) / float(refImage.getHeight());
+                       const float     xf                      = (float(x) + .5f) / float(width);
+                       const float     yf                      = (float(height - y - 1) +.5f) / float(height);
                        const float     oow                     = ((xf + yf) < 1.0f)
                                                                                ? projectedTriInterpolate(Vec3(m_w[0], m_w[1], m_w[2]), Vec3(m_w[0], m_w[1], m_w[2]), xf, yf)
-                                                                               : projectedTriInterpolate(Vec3(m_w[3], m_w[2], m_w[1]), Vec3(m_w[3], m_w[2], m_w[1]), 1.0f-xf, 1.0f-yf);
+                                                                               : projectedTriInterpolate(Vec3(m_w[3], m_w[2], m_w[1]), Vec3(m_w[3], m_w[2], m_w[1]), 1.0f - xf, 1.0f - yf);
                        const Vec4      color           (0.0f, oow - 1.0f, 0.0f, 1.0f);
+                       const Vec4      resultColor     = getResultImage().getAccess().getPixel(x, y);
 
-                       refImage.setPixel(x, y, RGBA(color));
+                       if (de::abs(color.x() - resultColor.x()) > precision ||
+                               de::abs(color.y() - resultColor.y()) > precision ||
+                               de::abs(color.z() - resultColor.z()) > precision)
+                       return TestStatus::fail("Image mismatch");
                }
        }
 
-       compareOk = pixelThresholdCompare(m_context.getTestContext().getLog(), "Result", "Image comparison result", refImage, resImage, threshold, COMPARE_LOG_RESULT);
-
-       if (compareOk)
-               return TestStatus::pass("Result image matches reference");
-       else
-               return TestStatus::fail("Image mismatch");
+       return TestStatus::pass("Result image matches reference");
 }
 
 void BuiltinGlFragCoordWCaseInstance::setupDefaultInputs (void)