Use 4 colors in Checkered test shader

This shader previously output red and green in a checkered pattern (with four regions). This makes it hard to verify that the output is not rotated / flipped. This change makes the shader output: +--------+--------+ | red | blue | +--------+--------+ | green | yellow | +--------+--------+ Bug: angleproject:4901 Change-Id: I02723306dec17d1419f11d9f76e96b1cefc3bf06 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2498261Reviewed-by: Ian Elliott <ianelliott@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>

Use 4 colors in Checkered test shader
9a47fe71 · Shahbaz Youssefi · Commit Bot · 98c5ff6b · 9a47fe71 · 9a47fe71
Commit 9a47fe71 authored Oct 26, 2020 by Shahbaz Youssefi Committed by Commit Bot Oct 27, 2020
Showing with 26 additions and 5 deletions

BlitFramebufferANGLETest.cpp src/tests/gl_tests/BlitFramebufferANGLETest.cpp +0 -0

shader_utils.cpp util/shader_utils.cpp +19 -3

shader_utils.h util/shader_utils.h +7 -2

No files found.
--- a/src/tests/gl_tests/BlitFramebufferANGLETest.cpp
+++ b/src/tests/gl_tests/BlitFramebufferANGLETest.cpp
--- a/util/shader_utils.cpp
+++ b/util/shader_utils.cpp
@@ -405,13 +405,29 @@ varying vec4 v_position;
 void main()
 {
-    if (v_position.x * v_position.y > 0.0)
+    bool isLeft = v_position.x < 0.0;
+    bool isTop = v_position.y < 0.0;
+    if (isLeft)
    {
-        gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
+        if (isTop)
+        {
+            gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
+        }
+        else
+        {
+            gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
+        }
    }
    else
    {
-        gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
+        if (isTop)
+        {
+            gl_FragColor = vec4(0.0, 0.0, 1.0, 1.0);
+        }
+        else
+        {
+            gl_FragColor = vec4(1.0, 1.0, 0.0, 1.0);
+        }
    }
 })";
 }

--- a/util/shader_utils.h
+++ b/util/shader_utils.h
@@ -79,8 +79,13 @@ ANGLE_UTIL_EXPORT const char *Texture2D();
 namespace fs
 {
-// A shader that renders a simple checker pattern of red and green. X axis and y axis separate the
+// A shader that renders a simple checker pattern of red, green and blue. X axis and Y axis separate
-// different colors. Needs varying v_position.
+// the different colors. Needs varying v_position.
+//
+// - X < 0 && y < 0: Red
+// - X < 0 && y >= 0: Green
+// - X >= 0 && y < 0: Blue
+// - X >= 0 && y >= 0: Yellow
 ANGLE_UTIL_EXPORT const char *Checkered();
 // A shader that fills with color taken from uniform named "color".