Verify texImage2D and texSubImage2D code paths with potentially subsampled images (RGBA/UNSIGNED_BYTE)

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".

Testing texImage2D with flipY=true
Checking upper left corner
PASS shouldBe 255,0,0
Checking middle
PASS shouldBe 0,255,0
Checking bottom right corner
PASS shouldBe 0,0,255
Testing texImage2D with flipY=false
Checking upper left corner
PASS shouldBe 0,255,0
Checking middle
PASS shouldBe 0,255,0
Checking bottom right corner
PASS shouldBe 0,255,0
Testing texSubImage2D with flipY=true
Checking upper left corner
PASS shouldBe 255,0,0
Checking middle
PASS shouldBe 0,255,0
Checking bottom right corner
PASS shouldBe 0,0,255
Testing texSubImage2D with flipY=false
Checking upper left corner
PASS shouldBe 0,255,0
Checking middle
PASS shouldBe 0,255,0
Checking bottom right corner
PASS shouldBe 0,255,0
PASS getError was expected value: NO_ERROR : should be no errors
PASS successfullyParsed is true

TEST COMPLETE