Index: cc/resources/texture_compressor_etc1.cc |
diff --git a/cc/resources/texture_compressor_etc1.cc b/cc/resources/texture_compressor_etc1.cc |
index 61c4438c21862342f8cf0ca10b19a375364a581c..03055437be666d533f9ae99c651d2568fd8baab1 100644 |
--- a/cc/resources/texture_compressor_etc1.cc |
+++ b/cc/resources/texture_compressor_etc1.cc |
@@ -20,194 +20,21 @@ |
namespace { |
-template <typename T> |
-inline T clamp(T val, T min, T max) { |
- return val < min ? min : (val > max ? max : val); |
-} |
- |
-inline uint8_t round_to_5_bits(float val) { |
- return clamp<uint8_t>(val * 31.0f / 255.0f + 0.5f, 0, 31); |
-} |
- |
-inline uint8_t round_to_4_bits(float val) { |
- return clamp<uint8_t>(val * 15.0f / 255.0f + 0.5f, 0, 15); |
-} |
- |
-union Color { |
- struct BgraColorType { |
- uint8_t b; |
- uint8_t g; |
- uint8_t r; |
- uint8_t a; |
- } channels; |
- uint8_t components[4]; |
- uint32_t bits; |
-}; |
- |
-/* |
- * Codeword tables. |
- * See: Table 3.17.2 |
- */ |
-static const int16_t g_codeword_tables[8][4] = {{-8, -2, 2, 8}, |
- {-17, -5, 5, 17}, |
- {-29, -9, 9, 29}, |
- {-42, -13, 13, 42}, |
- {-60, -18, 18, 60}, |
- {-80, -24, 24, 80}, |
- {-106, -33, 33, 106}, |
- {-183, -47, 47, 183}}; |
- |
-/* |
- * Maps modifier indices to pixel index values. |
- * See: Table 3.17.3 |
- */ |
-static const uint8_t g_mod_to_pix[4] = {3, 2, 0, 1}; |
- |
-/* |
- * The ETC1 specification index texels as follows: |
- * |
- * [a][e][i][m] [ 0][ 4][ 8][12] |
- * [b][f][j][n] <-> [ 1][ 5][ 9][13] |
- * [c][g][k][o] [ 2][ 6][10][14] |
- * [d][h][l][p] [ 3][ 7][11][15] |
- * |
- * However, when extracting sub blocks from BGRA data the natural array |
- * indexing order ends up different: |
- * |
- * vertical0: [a][e][b][f] horizontal0: [a][e][i][m] |
- * [c][g][d][h] [b][f][j][n] |
- * vertical1: [i][m][j][n] horizontal1: [c][g][k][o] |
- * [k][o][l][p] [d][h][l][p] |
- * |
- * In order to translate from the natural array indices in a sub block to the |
- * indices (number) used by specification and hardware we use this table. |
- */ |
-static const uint8_t g_idx_to_num[4][8] = { |
- {0, 4, 1, 5, 2, 6, 3, 7}, // Vertical block 0. |
- {8, 12, 9, 13, 10, 14, 11, 15}, // Vertical block 1. |
- {0, 4, 8, 12, 1, 5, 9, 13}, // Horizontal block 0. |
- {2, 6, 10, 14, 3, 7, 11, 15} // Horizontal block 1. |
-}; |
- |
-inline void WriteColors444(uint8_t* block, |
- const Color& color0, |
- const Color& color1) { |
- block[0] = (color0.channels.r & 0xf0) | (color1.channels.r >> 4); |
- block[1] = (color0.channels.g & 0xf0) | (color1.channels.g >> 4); |
- block[2] = (color0.channels.b & 0xf0) | (color1.channels.b >> 4); |
-} |
- |
-inline void WriteColors555(uint8_t* block, |
- const Color& color0, |
- const Color& color1) { |
- // Table for conversion to 3-bit two complement format. |
- static const uint8_t two_compl_trans_table[8] = { |
- 4, // -4 (100b) |
- 5, // -3 (101b) |
- 6, // -2 (110b) |
- 7, // -1 (111b) |
- 0, // 0 (000b) |
- 1, // 1 (001b) |
- 2, // 2 (010b) |
- 3, // 3 (011b) |
- }; |
- |
- int16_t delta_r = |
- static_cast<int16_t>(color1.channels.r >> 3) - (color0.channels.r >> 3); |
- int16_t delta_g = |
- static_cast<int16_t>(color1.channels.g >> 3) - (color0.channels.g >> 3); |
- int16_t delta_b = |
- static_cast<int16_t>(color1.channels.b >> 3) - (color0.channels.b >> 3); |
- DCHECK(delta_r >= -4 && delta_r <= 3); |
- DCHECK(delta_g >= -4 && delta_g <= 3); |
- DCHECK(delta_b >= -4 && delta_b <= 3); |
- |
- block[0] = (color0.channels.r & 0xf8) | two_compl_trans_table[delta_r + 4]; |
- block[1] = (color0.channels.g & 0xf8) | two_compl_trans_table[delta_g + 4]; |
- block[2] = (color0.channels.b & 0xf8) | two_compl_trans_table[delta_b + 4]; |
-} |
- |
-inline void WriteCodewordTable(uint8_t* block, |
- uint8_t sub_block_id, |
- uint8_t table) { |
- DCHECK_LT(sub_block_id, 2); |
- DCHECK_LT(table, 8); |
- |
- uint8_t shift = (2 + (3 - sub_block_id * 3)); |
- block[3] &= ~(0x07 << shift); |
- block[3] |= table << shift; |
-} |
- |
-inline void WritePixelData(uint8_t* block, uint32_t pixel_data) { |
- block[4] |= pixel_data >> 24; |
- block[5] |= (pixel_data >> 16) & 0xff; |
- block[6] |= (pixel_data >> 8) & 0xff; |
- block[7] |= pixel_data & 0xff; |
-} |
- |
-inline void WriteFlip(uint8_t* block, bool flip) { |
- block[3] &= ~0x01; |
- block[3] |= static_cast<uint8_t>(flip); |
-} |
- |
-inline void WriteDiff(uint8_t* block, bool diff) { |
- block[3] &= ~0x02; |
- block[3] |= static_cast<uint8_t>(diff) << 1; |
-} |
- |
-/** |
- * Compress and rounds BGR888 into BGR444. The resulting BGR444 color is |
- * expanded to BGR888 as it would be in hardware after decompression. The |
- * actual 444-bit data is available in the four most significant bits of each |
- * channel. |
- */ |
-inline Color MakeColor444(const float* bgr) { |
- uint8_t b4 = round_to_4_bits(bgr[0]); |
- uint8_t g4 = round_to_4_bits(bgr[1]); |
- uint8_t r4 = round_to_4_bits(bgr[2]); |
- Color bgr444; |
- bgr444.channels.b = (b4 << 4) | b4; |
- bgr444.channels.g = (g4 << 4) | g4; |
- bgr444.channels.r = (r4 << 4) | r4; |
- return bgr444; |
-} |
- |
-/** |
- * Compress and rounds BGR888 into BGR555. The resulting BGR555 color is |
- * expanded to BGR888 as it would be in hardware after decompression. The |
- * actual 555-bit data is available in the five most significant bits of each |
- * channel. |
- */ |
-inline Color MakeColor555(const float* bgr) { |
- uint8_t b5 = round_to_5_bits(bgr[0]); |
- uint8_t g5 = round_to_5_bits(bgr[1]); |
- uint8_t r5 = round_to_5_bits(bgr[2]); |
- Color bgr555; |
- bgr555.channels.b = (b5 << 3) | (b5 >> 2); |
- bgr555.channels.g = (g5 << 3) | (g5 >> 2); |
- bgr555.channels.r = (r5 << 3) | (r5 >> 2); |
- return bgr555; |
-} |
- |
-/** |
- * Constructs a color from a given base color and luminance value. |
- */ |
-inline Color MakeColor(const Color& base, int16_t lum) { |
+// Constructs a color from a given base color and luminance value. |
+inline cc::Color MakeColor(const cc::Color& base, int16_t lum) { |
int b = static_cast<int>(base.channels.b) + lum; |
int g = static_cast<int>(base.channels.g) + lum; |
int r = static_cast<int>(base.channels.r) + lum; |
- Color color; |
- color.channels.b = static_cast<uint8_t>(clamp(b, 0, 255)); |
- color.channels.g = static_cast<uint8_t>(clamp(g, 0, 255)); |
- color.channels.r = static_cast<uint8_t>(clamp(r, 0, 255)); |
+ cc::Color color; |
+ color.channels.b = static_cast<uint8_t>(cc::clamp(b, 0, 255)); |
+ color.channels.g = static_cast<uint8_t>(cc::clamp(g, 0, 255)); |
+ color.channels.r = static_cast<uint8_t>(cc::clamp(r, 0, 255)); |
return color; |
} |
-/** |
- * Calculates the error metric for two colors. A small error signals that the |
- * colors are similar to each other, a large error the signals the opposite. |
- */ |
-inline uint32_t GetColorError(const Color& u, const Color& v) { |
+// Calculates the error metric for two colors. A small error signals that the |
+// colors are similar to each other, a large error the signals the opposite. |
+inline uint32_t GetColorError(const cc::Color& u, const cc::Color& v) { |
#ifdef USE_PERCEIVED_ERROR_METRIC |
float delta_b = static_cast<float>(u.channels.b) - v.channels.b; |
float delta_g = static_cast<float>(u.channels.g) - v.channels.g; |
@@ -223,7 +50,7 @@ inline uint32_t GetColorError(const Color& u, const Color& v) { |
#endif |
} |
-void GetAverageColor(const Color* src, float* avg_color) { |
+void GetAverageColor(const cc::Color* src, float* avg_color) { |
uint32_t sum_b = 0, sum_g = 0, sum_r = 0; |
for (unsigned int i = 0; i < 8; ++i) { |
@@ -239,8 +66,8 @@ void GetAverageColor(const Color* src, float* avg_color) { |
} |
void ComputeLuminance(uint8_t* block, |
- const Color* src, |
- const Color& base, |
+ const cc::Color* src, |
+ const cc::Color& base, |
int sub_block_id, |
const uint8_t* idx_to_num_tab) { |
uint32_t best_tbl_err = std::numeric_limits<uint32_t>::max(); |
@@ -252,9 +79,9 @@ void ComputeLuminance(uint8_t* block, |
for (unsigned int tbl_idx = 0; tbl_idx < 8; ++tbl_idx) { |
// Pre-compute all the candidate colors; combinations of the base color and |
// all available luminance values. |
- Color candidate_color[4]; // [modifier] |
+ cc::Color candidate_color[4]; // [modifier] |
for (unsigned int mod_idx = 0; mod_idx < 4; ++mod_idx) { |
- int16_t lum = g_codeword_tables[tbl_idx][mod_idx]; |
+ int16_t lum = cc::g_codeword_tables[tbl_idx][mod_idx]; |
candidate_color[mod_idx] = MakeColor(base, lum); |
} |
@@ -265,7 +92,7 @@ void ComputeLuminance(uint8_t* block, |
// smallest error. |
uint32_t best_mod_err = std::numeric_limits<uint32_t>::max(); |
for (unsigned int mod_idx = 0; mod_idx < 4; ++mod_idx) { |
- const Color& color = candidate_color[mod_idx]; |
+ const cc::Color& color = candidate_color[mod_idx]; |
uint32_t mod_err = GetColorError(src[i], color); |
if (mod_err < best_mod_err) { |
@@ -291,13 +118,13 @@ void ComputeLuminance(uint8_t* block, |
} |
} |
- WriteCodewordTable(block, sub_block_id, best_tbl_idx); |
+ cc::WriteCodewordTable(block, sub_block_id, best_tbl_idx); |
uint32_t pix_data = 0; |
for (unsigned int i = 0; i < 8; ++i) { |
uint8_t mod_idx = best_mod_idx[best_tbl_idx][i]; |
- uint8_t pix_idx = g_mod_to_pix[mod_idx]; |
+ uint8_t pix_idx = cc::g_mod_to_pix[mod_idx]; |
uint32_t lsb = pix_idx & 0x1; |
uint32_t msb = pix_idx >> 1; |
@@ -308,7 +135,7 @@ void ComputeLuminance(uint8_t* block, |
pix_data |= lsb << (texel_num); |
} |
- WritePixelData(block, pix_data); |
+ cc::WritePixelData(block, pix_data); |
} |
/** |
@@ -316,7 +143,7 @@ void ComputeLuminance(uint8_t* block, |
* block. If it's not the function will bail out without writing anything to |
* the destination buffer. |
*/ |
-bool TryCompressSolidBlock(uint8_t* dst, const Color* src) { |
+bool TryCompressSolidBlock(uint8_t* dst, const cc::Color* src) { |
for (unsigned int i = 1; i < 16; ++i) { |
if (src[i].bits != src[0].bits) |
return false; |
@@ -328,11 +155,11 @@ bool TryCompressSolidBlock(uint8_t* dst, const Color* src) { |
float src_color_float[3] = {static_cast<float>(src->channels.b), |
static_cast<float>(src->channels.g), |
static_cast<float>(src->channels.r)}; |
- Color base = MakeColor555(src_color_float); |
+ cc::Color base = cc::MakeColor555(src_color_float); |
- WriteDiff(dst, true); |
- WriteFlip(dst, false); |
- WriteColors555(dst, base, base); |
+ cc::WriteDiff(dst, true); |
+ cc::WriteFlip(dst, false); |
+ cc::WriteColors555(dst, base, base); |
uint8_t best_tbl_idx = 0; |
uint8_t best_mod_idx = 0; |
@@ -344,8 +171,8 @@ bool TryCompressSolidBlock(uint8_t* dst, const Color* src) { |
// Try all modifiers in the current table to find which one gives the |
// smallest error. |
for (unsigned int mod_idx = 0; mod_idx < 4; ++mod_idx) { |
- int16_t lum = g_codeword_tables[tbl_idx][mod_idx]; |
- const Color& color = MakeColor(base, lum); |
+ int16_t lum = cc::g_codeword_tables[tbl_idx][mod_idx]; |
+ const cc::Color& color = MakeColor(base, lum); |
uint32_t mod_err = GetColorError(*src, color); |
if (mod_err < best_mod_err) { |
@@ -362,10 +189,10 @@ bool TryCompressSolidBlock(uint8_t* dst, const Color* src) { |
break; |
} |
- WriteCodewordTable(dst, 0, best_tbl_idx); |
- WriteCodewordTable(dst, 1, best_tbl_idx); |
+ cc::WriteCodewordTable(dst, 0, best_tbl_idx); |
+ cc::WriteCodewordTable(dst, 1, best_tbl_idx); |
- uint8_t pix_idx = g_mod_to_pix[best_mod_idx]; |
+ uint8_t pix_idx = cc::g_mod_to_pix[best_mod_idx]; |
uint32_t lsb = pix_idx & 0x1; |
uint32_t msb = pix_idx >> 1; |
@@ -373,23 +200,26 @@ bool TryCompressSolidBlock(uint8_t* dst, const Color* src) { |
for (unsigned int i = 0; i < 2; ++i) { |
for (unsigned int j = 0; j < 8; ++j) { |
// Obtain the texel number as specified in the standard. |
- int texel_num = g_idx_to_num[i][j]; |
+ int texel_num = cc::g_idx_to_num[i][j]; |
pix_data |= msb << (texel_num + 16); |
pix_data |= lsb << (texel_num); |
} |
} |
- WritePixelData(dst, pix_data); |
+ cc::WritePixelData(dst, pix_data); |
return true; |
} |
-void CompressBlock(uint8_t* dst, const Color* ver_src, const Color* hor_src) { |
+void CompressBlock(uint8_t* dst, |
+ const cc::Color* ver_src, |
+ const cc::Color* hor_src) { |
if (TryCompressSolidBlock(dst, ver_src)) |
return; |
- const Color* sub_block_src[4] = {ver_src, ver_src + 8, hor_src, hor_src + 8}; |
+ const cc::Color* sub_block_src[4] = { |
+ ver_src, ver_src + 8, hor_src, hor_src + 8}; |
- Color sub_block_avg[4]; |
+ cc::Color sub_block_avg[4]; |
bool use_differential[2] = {true, true}; |
// Compute the average color for each sub block and determine if differential |
@@ -397,11 +227,11 @@ void CompressBlock(uint8_t* dst, const Color* ver_src, const Color* hor_src) { |
for (unsigned int i = 0, j = 1; i < 4; i += 2, j += 2) { |
float avg_color_0[3]; |
GetAverageColor(sub_block_src[i], avg_color_0); |
- Color avg_color_555_0 = MakeColor555(avg_color_0); |
+ cc::Color avg_color_555_0 = cc::MakeColor555(avg_color_0); |
float avg_color_1[3]; |
GetAverageColor(sub_block_src[j], avg_color_1); |
- Color avg_color_555_1 = MakeColor555(avg_color_1); |
+ cc::Color avg_color_555_1 = cc::MakeColor555(avg_color_1); |
for (unsigned int light_idx = 0; light_idx < 3; ++light_idx) { |
int u = avg_color_555_0.components[light_idx] >> 3; |
@@ -410,8 +240,8 @@ void CompressBlock(uint8_t* dst, const Color* ver_src, const Color* hor_src) { |
int component_diff = v - u; |
if (component_diff < -4 || component_diff > 3) { |
use_differential[i / 2] = false; |
- sub_block_avg[i] = MakeColor444(avg_color_0); |
- sub_block_avg[j] = MakeColor444(avg_color_1); |
+ sub_block_avg[i] = cc::MakeColor444(avg_color_0); |
+ sub_block_avg[j] = cc::MakeColor444(avg_color_1); |
} else { |
sub_block_avg[i] = avg_color_555_0; |
sub_block_avg[j] = avg_color_555_1; |
@@ -435,28 +265,28 @@ void CompressBlock(uint8_t* dst, const Color* ver_src, const Color* hor_src) { |
// Clear destination buffer so that we can "or" in the results. |
memset(dst, 0, 8); |
- WriteDiff(dst, use_differential[!!flip]); |
- WriteFlip(dst, flip); |
+ cc::WriteDiff(dst, use_differential[!!flip]); |
+ cc::WriteFlip(dst, flip); |
uint8_t sub_block_off_0 = flip ? 2 : 0; |
uint8_t sub_block_off_1 = sub_block_off_0 + 1; |
if (use_differential[!!flip]) { |
- WriteColors555(dst, sub_block_avg[sub_block_off_0], |
- sub_block_avg[sub_block_off_1]); |
+ cc::WriteColors555(dst, sub_block_avg[sub_block_off_0], |
+ sub_block_avg[sub_block_off_1]); |
} else { |
- WriteColors444(dst, sub_block_avg[sub_block_off_0], |
- sub_block_avg[sub_block_off_1]); |
+ cc::WriteColors444(dst, sub_block_avg[sub_block_off_0], |
+ sub_block_avg[sub_block_off_1]); |
} |
// Compute luminance for the first sub block. |
ComputeLuminance(dst, sub_block_src[sub_block_off_0], |
sub_block_avg[sub_block_off_0], 0, |
- g_idx_to_num[sub_block_off_0]); |
+ cc::g_idx_to_num[sub_block_off_0]); |
// Compute luminance for the second sub block. |
ComputeLuminance(dst, sub_block_src[sub_block_off_1], |
sub_block_avg[sub_block_off_1], 1, |
- g_idx_to_num[sub_block_off_1]); |
+ cc::g_idx_to_num[sub_block_off_1]); |
} |
} // namespace |
@@ -468,8 +298,10 @@ void TextureCompressorETC1::Compress(const uint8_t* src, |
int width, |
int height, |
Quality quality) { |
- DCHECK(width >= 4 && (width & 3) == 0); |
- DCHECK(height >= 4 && (height & 3) == 0); |
+ DCHECK_GE(width, 4); |
+ DCHECK_EQ((width & 3), 0); |
+ DCHECK_GE(height, 4); |
+ DCHECK_EQ((height & 3), 0); |
Color ver_blocks[16]; |
Color hor_blocks[16]; |