SkRasterPipeline: implement support for SkTableColorFilter

This adds and uses a byte_tables stage that converts to bytes, looks up
in the tables, then converts back to floats.

We treat this as color filter as pure math, not considering anything
colorspace related: no transfer functions, no gamut to change, etc.

Change-Id: If5fefc1bcef61a0fb0ae279002a0dd1547e429ea
Reviewed-on: https://skia-review.googlesource.com/7413
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>

diff --git a/src/core/SkRasterPipeline.h b/src/core/SkRasterPipeline.h
index 558eead..44aa379 100644 (file)
--- a/src/core/SkRasterPipeline.h
+++ b/src/core/SkRasterPipeline.h
@@ -94,7 +94,8 @@
     M(bicubic_n3x) M(bicubic_n1x) M(bicubic_p1x) M(bicubic_p3x)  \
     M(bicubic_n3y) M(bicubic_n1y) M(bicubic_p1y) M(bicubic_p3y)  \
     M(save_xy) M(accumulate)                                     \
-    M(linear_gradient_2stops)
+    M(linear_gradient_2stops)                                    \
+    M(byte_tables)
 
 class SkRasterPipeline {
 public:

diff --git a/src/effects/SkTableColorFilter.cpp b/src/effects/SkTableColorFilter.cpp
index 6934a3e..3634946 100644 (file)
--- a/src/effects/SkTableColorFilter.cpp
+++ b/src/effects/SkTableColorFilter.cpp
@@ -7,13 +7,50 @@
 
 #include "SkTableColorFilter.h"
 
+#include "SkArenaAlloc.h"
 #include "SkBitmap.h"
 #include "SkColorPriv.h"
+#include "SkRasterPipeline.h"
 #include "SkReadBuffer.h"
 #include "SkString.h"
 #include "SkUnPreMultiply.h"
 #include "SkWriteBuffer.h"
 
+static const uint8_t gIdentityTable[] = {
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+    0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
+    0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
+    0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
+    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
+    0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
+    0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
+    0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
+    0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
+    0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
+    0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
+    0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
+    0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+    0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
+    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+    0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
+    0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
+    0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F,
+    0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7,
+    0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
+    0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7,
+    0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
+    0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7,
+    0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF,
+    0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7,
+    0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
+    0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7,
+    0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
+    0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
+    0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF
+};
+
 class SkTable_ColorFilter : public SkColorFilter {
 public:
     SkTable_ColorFilter(const uint8_t tableA[], const uint8_t tableR[],
@@ -65,6 +102,32 @@ public:
         kB_Flag = 1 << 3,
     };
 
+    bool onAppendStages(SkRasterPipeline* p, SkColorSpace*, SkArenaAlloc* alloc,
+                        bool shaderIsOpaque) const override {
+        const uint8_t *r = gIdentityTable,
+                      *g = gIdentityTable,
+                      *b = gIdentityTable,
+                      *a = gIdentityTable;
+        const uint8_t* ptr = fStorage;
+        if (fFlags & kA_Flag) { a = ptr; ptr += 256; }
+        if (fFlags & kR_Flag) { r = ptr; ptr += 256; }
+        if (fFlags & kG_Flag) { g = ptr; ptr += 256; }
+        if (fFlags & kB_Flag) { b = ptr;             }
+
+        if (!shaderIsOpaque) {
+            p->append(SkRasterPipeline::unpremul);
+        }
+
+        struct Tables { const uint8_t *r, *g, *b, *a; };
+        p->append(SkRasterPipeline::byte_tables, alloc->make<Tables>(Tables{r,g,b,a}));
+
+        bool definitelyOpaque = shaderIsOpaque && a[0xff] == 0xff;
+        if (!definitelyOpaque) {
+            p->append(SkRasterPipeline::premul);
+        }
+        return true;
+    }
+
 protected:
     void flatten(SkWriteBuffer&) const override;
 
@@ -79,41 +142,6 @@ private:
     typedef SkColorFilter INHERITED;
 };
 
-static const uint8_t gIdentityTable[] = {
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
-    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
-    0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
-    0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
-    0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
-    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
-    0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
-    0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
-    0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
-    0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
-    0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
-    0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
-    0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
-    0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
-    0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
-    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
-    0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
-    0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
-    0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F,
-    0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7,
-    0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
-    0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7,
-    0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
-    0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7,
-    0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF,
-    0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7,
-    0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
-    0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7,
-    0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
-    0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
-    0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF
-};
-
 void SkTable_ColorFilter::filterSpan(const SkPMColor src[], int count, SkPMColor dst[]) const {
     const uint8_t* table = fStorage;
     const uint8_t* tableA = gIdentityTable;

diff --git a/src/opts/SkRasterPipeline_opts.h b/src/opts/SkRasterPipeline_opts.h
index 5491535..f4648ba 100644 (file)
--- a/src/opts/SkRasterPipeline_opts.h
+++ b/src/opts/SkRasterPipeline_opts.h
@@ -1063,6 +1063,16 @@ STAGE_CTX(linear_gradient_2stops, const SkPM4f*) {
     a = SkNf_fma(t, dc.a(), c0.a());
 }
 
+STAGE_CTX(byte_tables, const void*) {
+    struct Tables { const uint8_t *r, *g, *b, *a; };
+    auto tables = (const Tables*)ctx;
+
+    r = SkNf_from_byte(gather(tail, tables->r, SkNf_round(255.0f, r)));
+    g = SkNf_from_byte(gather(tail, tables->g, SkNf_round(255.0f, g)));
+    b = SkNf_from_byte(gather(tail, tables->b, SkNf_round(255.0f, b)));
+    a = SkNf_from_byte(gather(tail, tables->a, SkNf_round(255.0f, a)));
+}
+
 SI Fn enum_to_Fn(SkRasterPipeline::StockStage st) {
     switch (st) {
     #define M(stage) case SkRasterPipeline::stage: return stage;