Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(533)

Issues Search
    My Issues | Starred     Open | Closed | All

Unified Diff: src/utils/SkTextureCompressor_ASTC.cpp

Issue 417933005: Add preliminary ASTC encoder (Closed) Base URL: https://skia.googlesource.com/skia.git@master
Patch Set: Fix comments Created 6 years, 5 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« src/utils/SkTextureCompressor.h ('K') | « src/utils/SkTextureCompressor_ASTC.h ('k') | no next file » | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: src/utils/SkTextureCompressor_ASTC.cpp
diff --git a/src/utils/SkTextureCompressor_ASTC.cpp b/src/utils/SkTextureCompressor_ASTC.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..d16af1b2a589c33c2e242c7303d63002a8c7674c
--- /dev/null
+++ b/src/utils/SkTextureCompressor_ASTC.cpp
@@ -0,0 +1,261 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkTextureCompressor_ASTC.h"
+
+#include "SkBlitter.h"
+#include "SkEndian.h"
+
+// This table contains the weight values for each texel. This is used in determining
+// how to convert a 12x12 grid of alpha values into a 6x5 grid of index values. Since
+// we have a 6x5 grid, that gives 30 values that we have to compute. For each index,
+// we store up to 20 different triplets of values. In order the triplets are:
+// weight, texel-x, texel-y
+// The weight value corresponds to the amount that this index contributes to the final
+// index value of the given texel. Hence, we need to reconstruct the 6x5 index grid
+// from their relative contribution to the 12x12 texel grid.
+//
+// The algorithm is something like this:
+// foreach index i:
+// total-weight = 0;
+// total-alpha = 0;
+// for w = 1 to 20:
+// weight = table[i][w*3];
+// texel-x = table[i][w*3 + 1];
+// texel-y = table[i][w*3 + 2];
+// if weight >= 0:
+// total-weight += weight;
+// total-alpha += weight * alphas[texel-x][texel-y];
+//
+// total-alpha /= total-weight;
+// index = top three bits of total-alpha
+//
+// If the associated index does not contribute to 20 different texels (e.g. it's in
+// a corner), then the extra texels are stored with -1's in the table.
+
+static const int k6x5To12x12Table[30][60] = {
+{ 16, 0, 0, 9, 1, 0, 1, 2, 0, 10, 0, 1, 6, 1, 1, 1, 2, 1, 4, 0, 2, 2,
+ 1, 2, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 7, 1, 0, 15, 2, 0, 10, 3, 0, 3, 4, 0, 4, 1, 1, 9, 2, 1, 6, 3, 1, 2,
+ 4, 1, 2, 1, 2, 4, 2, 2, 3, 3, 2, 1, 4, 2, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 6, 3, 0, 13, 4, 0, 12, 5, 0, 4, 6, 0, 4, 3, 1, 8, 4, 1, 8, 5, 1, 3,
+ 6, 1, 1, 3, 2, 3, 4, 2, 3, 5, 2, 1, 6, 2, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 4, 5, 0, 12, 6, 0, 13, 7, 0, 6, 8, 0, 2, 5, 1, 7, 6, 1, 8, 7, 1, 4,
+ 8, 1, 1, 5, 2, 3, 6, 2, 3, 7, 2, 2, 8, 2, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 3, 7, 0, 10, 8, 0, 15, 9, 0, 7, 10, 0, 2, 7, 1, 6, 8, 1, 9, 9, 1, 4,
+ 10, 1, 1, 7, 2, 2, 8, 2, 4, 9, 2, 2, 10, 2, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 1, 9, 0, 9, 10, 0, 16, 11, 0, 1, 9, 1, 6, 10, 1, 10, 11, 1, 2, 10, 2, 4,
+ 11, 2, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 6, 0, 1, 3, 1, 1, 12, 0, 2, 7, 1, 2, 1, 2, 2, 15, 0, 3, 8, 1, 3, 1,
+ 2, 3, 9, 0, 4, 5, 1, 4, 1, 2, 4, 3, 0, 5, 2, 1, 5, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 3, 1, 1, 6, 2, 1, 4, 3, 1, 1, 4, 1, 5, 1, 2, 11, 2, 2, 7, 3, 2, 2,
+ 4, 2, 7, 1, 3, 14, 2, 3, 9, 3, 3, 3, 4, 3, 4, 1, 4, 8, 2, 4, 6, 3,
+ 4, 2, 4, 4, 1, 1, 5, 3, 2, 5, 2, 3, 5, 1, 4, 5}, // n = 20
+{ 2, 3, 1, 5, 4, 1, 4, 5, 1, 1, 6, 1, 5, 3, 2, 10, 4, 2, 9, 5, 2, 3,
+ 6, 2, 6, 3, 3, 12, 4, 3, 11, 5, 3, 4, 6, 3, 3, 3, 4, 7, 4, 4, 7, 5,
+ 4, 2, 6, 4, 1, 3, 5, 2, 4, 5, 2, 5, 5, 1, 6, 5}, // n = 20
+{ 2, 5, 1, 5, 6, 1, 5, 7, 1, 2, 8, 1, 3, 5, 2, 9, 6, 2, 10, 7, 2, 4,
+ 8, 2, 4, 5, 3, 11, 6, 3, 12, 7, 3, 6, 8, 3, 2, 5, 4, 7, 6, 4, 7, 7,
+ 4, 3, 8, 4, 1, 5, 5, 2, 6, 5, 2, 7, 5, 1, 8, 5}, // n = 20
+{ 1, 7, 1, 4, 8, 1, 6, 9, 1, 3, 10, 1, 2, 7, 2, 8, 8, 2, 11, 9, 2, 5,
+ 10, 2, 3, 7, 3, 9, 8, 3, 14, 9, 3, 7, 10, 3, 2, 7, 4, 6, 8, 4, 8, 9,
+ 4, 4, 10, 4, 1, 7, 5, 2, 8, 5, 3, 9, 5, 1, 10, 5}, // n = 20
+{ 3, 10, 1, 6, 11, 1, 1, 9, 2, 7, 10, 2, 12, 11, 2, 1, 9, 3, 8, 10, 3, 15,
+ 11, 3, 1, 9, 4, 5, 10, 4, 9, 11, 4, 2, 10, 5, 3, 11, 5, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 1, 0, 3, 1, 1, 3, 7, 0, 4, 4, 1, 4, 13, 0, 5, 7, 1, 5, 1, 2, 5, 13,
+ 0, 6, 7, 1, 6, 1, 2, 6, 7, 0, 7, 4, 1, 7, 1, 0, 8, 1, 1, 8, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 1, 2, 3, 1, 3, 3, 3, 1, 4, 7, 2, 4, 4, 3, 4, 1, 4, 4, 6, 1, 5, 12,
+ 2, 5, 8, 3, 5, 2, 4, 5, 6, 1, 6, 12, 2, 6, 8, 3, 6, 2, 4, 6, 3, 1,
+ 7, 7, 2, 7, 4, 3, 7, 1, 4, 7, 1, 2, 8, 1, 3, 8}, // n = 20
+{ 1, 4, 3, 1, 5, 3, 3, 3, 4, 6, 4, 4, 5, 5, 4, 2, 6, 4, 5, 3, 5, 11,
+ 4, 5, 10, 5, 5, 3, 6, 5, 5, 3, 6, 11, 4, 6, 10, 5, 6, 3, 6, 6, 3, 3,
+ 7, 6, 4, 7, 5, 5, 7, 2, 6, 7, 1, 4, 8, 1, 5, 8}, // n = 20
+{ 1, 6, 3, 1, 7, 3, 2, 5, 4, 5, 6, 4, 6, 7, 4, 3, 8, 4, 3, 5, 5, 10,
+ 6, 5, 11, 7, 5, 5, 8, 5, 3, 5, 6, 10, 6, 6, 11, 7, 6, 5, 8, 6, 2, 5,
+ 7, 5, 6, 7, 6, 7, 7, 3, 8, 7, 1, 6, 8, 1, 7, 8}, // n = 20
+{ 1, 8, 3, 1, 9, 3, 1, 7, 4, 4, 8, 4, 7, 9, 4, 3, 10, 4, 2, 7, 5, 8,
+ 8, 5, 12, 9, 5, 6, 10, 5, 2, 7, 6, 8, 8, 6, 12, 9, 6, 6, 10, 6, 1, 7,
+ 7, 4, 8, 7, 7, 9, 7, 3, 10, 7, 1, 8, 8, 1, 9, 8}, // n = 20
+{ 1, 10, 3, 1, 11, 3, 4, 10, 4, 7, 11, 4, 1, 9, 5, 7, 10, 5, 13, 11, 5, 1,
+ 9, 6, 7, 10, 6, 13, 11, 6, 4, 10, 7, 7, 11, 7, 1, 10, 8, 1, 11, 8, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 3, 0, 6, 2, 1, 6, 9, 0, 7, 5, 1, 7, 1, 2, 7, 15, 0, 8, 8, 1, 8, 1,
+ 2, 8, 12, 0, 9, 7, 1, 9, 1, 2, 9, 6, 0, 10, 3, 1, 10, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 1, 1, 6, 3, 2, 6, 2, 3, 6, 1, 4, 6, 4, 1, 7, 8, 2, 7, 6, 3, 7, 2,
+ 4, 7, 7, 1, 8, 14, 2, 8, 9, 3, 8, 3, 4, 8, 5, 1, 9, 11, 2, 9, 8, 3,
+ 9, 2, 4, 9, 3, 1, 10, 6, 2, 10, 4, 3, 10, 1, 4, 10}, // n = 20
+{ 1, 3, 6, 2, 4, 6, 2, 5, 6, 1, 6, 6, 3, 3, 7, 7, 4, 7, 7, 5, 7, 2,
+ 6, 7, 6, 3, 8, 12, 4, 8, 11, 5, 8, 4, 6, 8, 4, 3, 9, 10, 4, 9, 9, 5,
+ 9, 3, 6, 9, 2, 3, 10, 5, 4, 10, 5, 5, 10, 2, 6, 10}, // n = 20
+{ 1, 5, 6, 2, 6, 6, 2, 7, 6, 1, 8, 6, 2, 5, 7, 7, 6, 7, 7, 7, 7, 3,
+ 8, 7, 4, 5, 8, 11, 6, 8, 12, 7, 8, 6, 8, 8, 3, 5, 9, 9, 6, 9, 10, 7,
+ 9, 5, 8, 9, 1, 5, 10, 4, 6, 10, 5, 7, 10, 2, 8, 10}, // n = 20
+{ 1, 7, 6, 2, 8, 6, 3, 9, 6, 1, 10, 6, 2, 7, 7, 6, 8, 7, 8, 9, 7, 4,
+ 10, 7, 3, 7, 8, 9, 8, 8, 14, 9, 8, 7, 10, 8, 2, 7, 9, 7, 8, 9, 11, 9,
+ 9, 5, 10, 9, 1, 7, 10, 4, 8, 10, 6, 9, 10, 3, 10, 10}, // n = 20
+{ 2, 10, 6, 3, 11, 6, 1, 9, 7, 5, 10, 7, 9, 11, 7, 1, 9, 8, 8, 10, 8, 15,
+ 11, 8, 1, 9, 9, 7, 10, 9, 12, 11, 9, 3, 10, 10, 6, 11, 10, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 4, 0, 9, 2, 1, 9, 10, 0, 10, 6, 1, 10, 1, 2, 10, 16, 0, 11, 9, 1, 11, 1,
+ 2, 11, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 2, 1, 9, 4, 2, 9, 2, 3, 9, 1, 4, 9, 4, 1, 10, 9, 2, 10, 6, 3, 10, 2,
+ 4, 10, 7, 1, 11, 15, 2, 11, 10, 3, 11, 3, 4, 11, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 2, 3, 9, 3, 4, 9, 3, 5, 9, 1, 6, 9, 4, 3, 10, 8, 4, 10, 7, 5, 10, 2,
+ 6, 10, 6, 3, 11, 13, 4, 11, 12, 5, 11, 4, 6, 11, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 1, 5, 9, 3, 6, 9, 3, 7, 9, 1, 8, 9, 3, 5, 10, 8, 6, 10, 8, 7, 10, 4,
+ 8, 10, 4, 5, 11, 12, 6, 11, 13, 7, 11, 6, 8, 11, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 1, 7, 9, 3, 8, 9, 4, 9, 9, 2, 10, 9, 2, 7, 10, 6, 8, 10, 9, 9, 10, 4,
+ 10, 10, 3, 7, 11, 10, 8, 11, 15, 9, 11, 7, 10, 11, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20
+{ 2, 10, 9, 4, 11, 9, 1, 9, 10, 6, 10, 10, 10, 11, 10, 1, 9, 11, 9, 10, 11, 16,
+ 11, 11, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0,
+ 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0} // n = 20
+};
+
+// Returns the alpha value of a texel at position (x, y) from src.
+// (x, y) are assumed to be in the range [0, 12).
+uint8_t get_alpha(const uint8_t *src, int rowBytes, int x, int y) {
robertphillips 2014/07/24 17:47:39 SkASSERT the x & y assumptions here ?
krajcevski 2014/07/24 19:59:08 Done.
+ return *(src + y*rowBytes + x);
+}
+
+// Compresses an ASTC block, by looking up the proper contributions from
+// k6x5To12x12Table and computing an index from the associated values.
+void compress_a8_astc_block(uint8_t** dst, const uint8_t* src, int rowBytes) {
+ uint8_t indices[5][6];
robertphillips 2014/07/24 17:47:39 Any reason you have the outer loop variable as 'j'
krajcevski 2014/07/24 19:59:08 Actually, we can just loop from 0 to 30, since we'
+ for (int j = 0; j < 5; ++j) {
+ for (int i = 0; i < 6; ++i) {
+ const int idx = j*6+i;
robertphillips 2014/07/24 17:47:39 weightTot, alphaTot ?
krajcevski 2014/07/24 19:59:08 Done.
+ int wtotal = 0;
+ int atotal = 0;
+ for (int w = 0; w < 20; ++w) {
+ const int weight = k6x5To12x12Table[idx][w*3];
+ const int x = k6x5To12x12Table[idx][w*3 + 1];
+ const int y = k6x5To12x12Table[idx][w*3 + 2];
+ if (weight > 0) {
+ wtotal += weight;
+ atotal += weight * get_alpha(src, rowBytes, x, y);
+ }
+ }
+
+ atotal = (atotal + (wtotal/2)) / wtotal;
+ indices[j][i] = atotal;
+ }
+ }
+
+ // Pack indices... The ASTC block layout is fairly complicated. An extensive
+ // description can be found here:
+ // https://www.opengl.org/registry/specs/KHR/texture_compression_astc_hdr.txt
+ //
+ // Here is a summary of the options that we've chosen:
+ // 1. Block mode: 0b00101110011
+ // - 6x5 texel grid
+ // - Single plane
+ // - Low-precision index values
+ // - Index range 0-7 (three bits per index)
+ // 2. Partitions: 0b00
+ // - One partition
+ // 3. Color Endpoint Mode: 0b0000
+ // - Direct luminance -- e0=(v0,v0,v0,0xFF); e1=(v1,v1,v1,0xFF);
+ // 4. 8-bit endpoints:
+ // v0 = 0, v1 = 255
+ //
+ // The rest of the block contains the 30 index values from before, which
robertphillips 2014/07/24 17:47:39 typo
krajcevski 2014/07/24 19:59:07 Done.
+ // is currently stored in the indices[5][6] varaible.
+ uint64_t top = 0x0000000001FE000173ULL;
+ uint64_t bottom = 0;
+ int idx = 0;
+ for (int j = 0; j < 5; ++j) {
+ for (int i = 0; i < 6; ++i) {
+ // This is our index.
+ uint8_t index = (indices[j][i] & 0xE0) >> 5;
+
+ // Since we read from the end of the block in reverse, the three-bit values
+ // need to have their bits reversed
robertphillips 2014/07/24 17:47:39 I don't know if this can land without a bit twiddl
krajcevski 2014/07/24 19:59:08 Yea, that's kind of ugly. I changed it so that we
+ switch(index) {
+ case 0:
+ case 2:
+ case 5:
+ case 7:
+ // Do nothing
+ break;
+
+ case 1:
+ index = 4;
+ break;
+ case 4:
+ index = 1;
+ break;
+ case 3:
+ index = 6;
+ break;
+ case 6:
+ index = 3;
+ break;
+ }
+
+ // Finally, place the index in the proper place in the block based
+ // on raster order.
+ if (idx <= 20) {
+ bottom |= static_cast<uint64_t>(index) << (61-idx*3);
+ } else if (idx > 21) {
+ top |= static_cast<uint64_t>(index) << (59-(idx-22)*3);
+ } else {
+ SkASSERT(21 == idx);
+ bottom |= index >> 2;
+ top |= static_cast<uint64_t>(index) << 62;
+ }
+
+ idx++;
+ }
+ }
+
+ uint64_t* dst64 = reinterpret_cast<uint64_t*>(*dst);
+ dst64[0] = SkEndian_SwapLE64(top);
+ dst64[1] = SkEndian_SwapLE64(bottom);
+
+ *dst += 16;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+namespace SkTextureCompressor {
+
+bool CompressA8To12x12ASTC(uint8_t* dst, const uint8_t* src, int width, int height, int rowBytes) {
+ if (width < 0 || ((width % 12) != 0) || height < 0 || ((height % 12) != 0)) {
+ return false;
+ }
+
+ uint8_t** dstPtr = &dst;
+ for (int j = 0; j < height; j+=12) {
+ for (int i = 0; i < width; i+=12) {
+ compress_a8_astc_block(dstPtr, src + j*rowBytes + i, rowBytes);
+ }
+ }
+
+ return true;
+}
+
+SkBlitter* CreateASTCBlitter(int width, int height, void* outputBuffer) {
+ // TODO (krajcevski)
+ return NULL;
+}
+
+} // SkTextureCompressor
« src/utils/SkTextureCompressor.h ('K') | « src/utils/SkTextureCompressor_ASTC.h ('k') | no next file » | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698