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Diffstat (limited to 'test/common/huffman.h')
| -rw-r--r-- | test/common/huffman.h | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/test/common/huffman.h b/test/common/huffman.h new file mode 100644 index 0000000000..53353aaa60 --- /dev/null +++ b/test/common/huffman.h @@ -0,0 +1,144 @@ +#include <cxxtest/TestSuite.h> +#include "common/huffman.h" +#include "common/bitstream.h" +#include "common/memstream.h" + +/** +* A test suite for the Huffman decoder in common/huffman.h +* The encoding used comes from the example on the Wikipedia page +* for Huffman. +* TODO: It could be improved by generating one at runtime. +*/ +class HuffmanTestSuite : public CxxTest::TestSuite { + public: + void test_get_with_full_symbols() { + + /* + * The class can be initialized with or without providing + * a max_length and a symbol table. + * We test with a table. + * + * Encoding (arbitrary, for testing purpouses): + * 0xA=010 + * 0xB=011 + * 0xC=11 + * 0xD=00 + * 0xE=10 + */ + + uint32 codeCount = 5; + uint8 maxLength = 3; + const uint8 lengths[] = {3,3,2,2,2}; + const uint32 codes[] = {0x2, 0x3, 0x3, 0x0, 0x2}; + const uint32 symbols[] = {0xA, 0xB, 0xC, 0xD, 0xE}; + + Common::Huffman h(maxLength, codeCount, codes, lengths, symbols); + + byte input[] = {0x4F, 0x20}; + // Provided input... + uint32 expected[] = {0xA, 0xB, 0xC, 0xD, 0xE, 0xD, 0xD}; + // ..and expected output. + + /* + * What should be going on: + * 010 011 11 00 10 00 00 = A B C D E D D + * = 0100 1111 0010 0000 = 0x4F20 + */ + + Common::MemoryReadStream ms(input, sizeof(input)); + Common::BitStream8MSB bs(ms); + + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[0]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[1]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[2]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[3]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[4]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[5]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[6]); + } + + void test_get_without_symbols() { + + /* + * This is basically the same as test_get_with_full_symbols, but + * I only pass the minimal required arguments. + * Specifically, I avoid passing the symbols table, so that + * array indices are used instead. + * + * Encoding becomes: + * + * 0=010 + * 1=011 + * 2=11 + * 3=00 + * 4=10 + */ + + uint32 codeCount = 5; + const uint8 lengths[] = {3,3,2,2,2}; + const uint32 codes[] = {0x2, 0x3, 0x3, 0x0, 0x2}; + + Common::Huffman h(0, codeCount, codes, lengths, 0); + + byte input[] = {0x4F, 0x20}; + uint32 expected[] = {0, 1, 2, 3, 4, 3 ,3}; + + Common::MemoryReadStream ms(input, sizeof(input)); + Common::BitStream8MSB bs(ms); + + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[0]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[1]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[2]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[3]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[4]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[5]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[6]); + } + + void test_get_after_set_symbols() { + + /* + * Another variation of test_get_with_full_symbols. + * I use the setSymbols method to define, a posteriori, + * an alphabet to be used in place of array indices. + * The encoding is, at first, + * 0=010 + * 1=011 + * 2=11 + * 3=00 + * 4=10 + * (=array indices). + */ + + uint32 codeCount = 5; + const uint8 lengths[] = {3,3,2,2,2}; + const uint32 codes[] = {0x2, 0x3, 0x3, 0x0, 0x2}; + + Common::Huffman h(0, codeCount, codes, lengths, 0); + + const uint32 symbols[] = {0xA, 0xB, 0xC, 0xD, 0xE}; + h.setSymbols(symbols); + + byte input[] = {0x4F, 0x20}; + uint32 expected[] = {0xA, 0xB, 0xC, 0xD, 0xE, 0xD, 0xD}; + + Common::MemoryReadStream ms(input, sizeof(input)); + Common::BitStream8MSB bs(ms); + + /* New symbols: + * A=010 + * B=011 + * C=11 + * D=00 + * E=10 + */ + + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[0]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[1]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[2]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[3]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[4]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[5]); + TS_ASSERT_EQUALS(h.getSymbol(bs), expected[6]); + } +}; |