gather_i8

CQ_INCLUDE_TRYBOTS=skia.primary:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD

Change-Id: Ia7a133f515e29e16700aabc0633c77a703425f41
Reviewed-on: https://skia-review.googlesource.com/5239
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>

3 files changed, 30 insertions, 16 deletions

diff --git a/src/image/SkImageShader.cpp b/src/image/SkImageShader.cpp
index 134cc1cd67..3def5ec345 100644
--- a/src/image/SkImageShader.cpp
+++ b/src/image/SkImageShader.cpp
@@ -289,7 +289,6 @@ bool SkImageShader::onAppendStages(SkRasterPipeline* p, SkColorSpace* dst, SkFal
     // TODO: all formats
     switch (info.colorType()) {
         case kAlpha_8_SkColorType:
-        case kIndex_8_SkColorType:
             return false;
         default: break;
     }
@@ -319,11 +318,11 @@ bool SkImageShader::onAppendStages(SkRasterPipeline* p, SkColorSpace* dst, SkFal
     }
 
     auto ctx = scratch->make<SkImageShaderContext>();
-
-    ctx->pixels   = pm.addr();
-    ctx->stride   = pm.rowBytesAsPixels();
-    ctx->width    = pm.width();
-    ctx->height   = pm.height();
+    ctx->pixels = pm.addr();
+    ctx->ctable = pm.ctable();
+    ctx->stride = pm.rowBytesAsPixels();
+    ctx->width  = pm.width();
+    ctx->height = pm.height();
     if (matrix.asAffine(ctx->matrix)) {
         p->append(SkRasterPipeline::matrix_2x3, ctx->matrix);
     } else {
@@ -343,6 +342,7 @@ bool SkImageShader::onAppendStages(SkRasterPipeline* p, SkColorSpace* dst, SkFal
             case kRepeat_TileMode: p->append(SkRasterPipeline::repeat_y, &ctx->height); break;
         }
         switch (info.colorType()) {
+            case kIndex_8_SkColorType:   p->append(SkRasterPipeline::gather_i8,   ctx); break;
             case kGray_8_SkColorType:    p->append(SkRasterPipeline::gather_g8,   ctx); break;
             case kRGB_565_SkColorType:   p->append(SkRasterPipeline::gather_565,  ctx); break;
             case kARGB_4444_SkColorType: p->append(SkRasterPipeline::gather_4444, ctx); break;
@@ -379,7 +379,11 @@ bool SkImageShader::onAppendStages(SkRasterPipeline* p, SkColorSpace* dst, SkFal
         p->append(SkRasterPipeline::move_dst_src);
     }
 
-    if (info.colorType() == kBGRA_8888_SkColorType) {
+    auto effective_color_type = [](SkColorType ct) {
+        return ct == kIndex_8_SkColorType ? kN32_SkColorType : ct;
+    };
+
+    if (effective_color_type(info.colorType()) == kBGRA_8888_SkColorType) {
         p->append(SkRasterPipeline::swap_rb);
     }
     if (info.alphaType() == kUnpremul_SkAlphaType) {
diff --git a/src/image/SkImageShaderContext.h b/src/image/SkImageShaderContext.h
index 96b30b0a26..cb562369a9 100644
--- a/src/image/SkImageShaderContext.h
+++ b/src/image/SkImageShaderContext.h
@@ -8,18 +8,21 @@
 #ifndef SkImageShaderContext_DEFINED
 #define SkImageShaderContext_DEFINED
 
+class SkColorTable;
+
 // Definition used by SkImageShader.cpp and SkRasterPipeline_opts.h.
 // Otherwise, completely uninteresting.
 
 struct SkImageShaderContext {
-    const void* pixels;
-    int         stride;
-    int         width;
-    int         height;
-    float       matrix[9];
-    float       x[8];
-    float       y[8];
-    float       scale[8];
+    const void*   pixels;
+    SkColorTable* ctable;
+    int           stride;
+    int           width;
+    int           height;
+    float         matrix[9];
+    float         x[8];
+    float         y[8];
+    float         scale[8];
 };
 
 #endif//SkImageShaderContext_DEFINED
diff --git a/src/opts/SkRasterPipeline_opts.h b/src/opts/SkRasterPipeline_opts.h
index 11447bcdf9..d38e0ca80d 100644
--- a/src/opts/SkRasterPipeline_opts.h
+++ b/src/opts/SkRasterPipeline_opts.h
@@ -768,7 +768,14 @@ SI SkNi offset_and_ptr(T** ptr, const void* ctx, const SkNf& x, const SkNf& y) {
 }
 
 STAGE(gather_a8) {}  // TODO
-STAGE(gather_i8) {}  // TODO
+STAGE(gather_i8) {
+    auto sc = (const SkImageShaderContext*)ctx;
+    const uint8_t* p;
+    SkNi offset = offset_and_ptr(&p, sc, r, g);
+
+    SkNi ix = SkNx_cast<int>(gather(tail, p, offset));
+    from_8888(gather(tail, sc->ctable->readColors(), ix), &r, &g, &b, &a);
+}
 STAGE(gather_g8) {
     const uint8_t* p;
     SkNi offset = offset_and_ptr(&p, ctx, r, g);