collapse parametric_{r,g,b} into parametric, remove _a and gamma_dst

parametric_a and gamma_dst were unused outside of unit tests.

In all other cases, we always use parametric_{r,g,b} together
and always pass them the same argument.  So we can collapse
them into a single stage like gamma and to/from_srgb.

Change-Id: I08cea896c7744f97b4f4bf9e029f5d643e45e177
Reviewed-on: https://skia-review.googlesource.com/140576
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Brian Osman <brianosman@google.com>

6 files changed, 20 insertions, 38 deletions

diff --git a/src/core/SkColorSpaceXformSteps.cpp b/src/core/SkColorSpaceXformSteps.cpp
index 77a9c6b05d..3abdb2f05a 100644
--- a/src/core/SkColorSpaceXformSteps.cpp
+++ b/src/core/SkColorSpaceXformSteps.cpp
@@ -115,9 +115,7 @@ void SkColorSpaceXformSteps::apply(SkRasterPipeline* p) const {
                    srcTF.fF == 0) {
             p->append(SkRasterPipeline::gamma, &srcTF.fG);
         } else {
-            p->append(SkRasterPipeline::parametric_r, &srcTF);
-            p->append(SkRasterPipeline::parametric_g, &srcTF);
-            p->append(SkRasterPipeline::parametric_b, &srcTF);
+            p->append(SkRasterPipeline::parametric, &srcTF);
         }
     }
     if (flags.gamut_transform) {
@@ -134,9 +132,7 @@ void SkColorSpaceXformSteps::apply(SkRasterPipeline* p) const {
                    dstTFInv.fF == 0) {
             p->append(SkRasterPipeline::gamma, &dstTFInv.fG);
         } else {
-            p->append(SkRasterPipeline::parametric_r, &dstTFInv);
-            p->append(SkRasterPipeline::parametric_g, &dstTFInv);
-            p->append(SkRasterPipeline::parametric_b, &dstTFInv);
+            p->append(SkRasterPipeline::parametric, &dstTFInv);
         }
     }
     if (flags.premul) { p->append(SkRasterPipeline::premul); }
diff --git a/src/core/SkConvertPixels.cpp b/src/core/SkConvertPixels.cpp
index 25645d485c..0434b92c2e 100644
--- a/src/core/SkConvertPixels.cpp
+++ b/src/core/SkConvertPixels.cpp
@@ -308,9 +308,7 @@ static void convert_with_pipeline(const SkImageInfo& dstInfo, void* dstRow, size
         if (is_just_gamma(srcFn)) {
             pipeline.append(SkRasterPipeline::gamma, &srcFn.fG);
         } else {
-            pipeline.append(SkRasterPipeline::parametric_r, &srcFn);
-            pipeline.append(SkRasterPipeline::parametric_g, &srcFn);
-            pipeline.append(SkRasterPipeline::parametric_b, &srcFn);
+            pipeline.append(SkRasterPipeline::parametric, &srcFn);
         }
     }
 
@@ -340,9 +338,7 @@ static void convert_with_pipeline(const SkImageInfo& dstInfo, void* dstRow, size
         if (is_just_gamma(dstFn)) {
             pipeline.append(SkRasterPipeline::gamma, &dstFn.fG);
         } else {
-            pipeline.append(SkRasterPipeline::parametric_r, &dstFn);
-            pipeline.append(SkRasterPipeline::parametric_g, &dstFn);
-            pipeline.append(SkRasterPipeline::parametric_b, &dstFn);
+            pipeline.append(SkRasterPipeline::parametric, &dstFn);
         }
     }
 
diff --git a/src/core/SkRasterPipeline.h b/src/core/SkRasterPipeline.h
index 0efdae518a..be197e4c6e 100644
--- a/src/core/SkRasterPipeline.h
+++ b/src/core/SkRasterPipeline.h
@@ -69,8 +69,7 @@
     M(matrix_translate) M(matrix_scale_translate)                  \
     M(matrix_2x3) M(matrix_3x3) M(matrix_3x4) M(matrix_4x5) M(matrix_4x3) \
     M(matrix_perspective)                                          \
-    M(parametric_r) M(parametric_g) M(parametric_b)                \
-    M(parametric_a) M(gamma) M(gamma_dst)                          \
+    M(parametric) M(gamma)                                         \
     M(mirror_x)   M(repeat_x)                                      \
     M(mirror_y)   M(repeat_y)                                      \
     M(decal_x)    M(decal_y)   M(decal_x_and_y)                    \
diff --git a/src/effects/SkHighContrastFilter.cpp b/src/effects/SkHighContrastFilter.cpp
index be6180a531..2d0b0f97fe 100644
--- a/src/effects/SkHighContrastFilter.cpp
+++ b/src/effects/SkHighContrastFilter.cpp
@@ -73,9 +73,7 @@ void SkHighContrast_Filter::onAppendStages(SkRasterPipeline* p,
         square->G = 2.0f; square->A = 1.0f;
         square->B = square->C = square->D = square->E = square->F = 0;
 
-        p->append(SkRasterPipeline::parametric_r, square);
-        p->append(SkRasterPipeline::parametric_g, square);
-        p->append(SkRasterPipeline::parametric_b, square);
+        p->append(SkRasterPipeline::parametric, square);
     }
 
     if (fConfig.fGrayscale) {
@@ -122,9 +120,7 @@ void SkHighContrast_Filter::onAppendStages(SkRasterPipeline* p,
         sqrt->G = 0.5f; sqrt->A = 1.0f;
         sqrt->B = sqrt->C = sqrt->D = sqrt->E = sqrt->F = 0;
 
-        p->append(SkRasterPipeline::parametric_r, sqrt);
-        p->append(SkRasterPipeline::parametric_g, sqrt);
-        p->append(SkRasterPipeline::parametric_b, sqrt);
+        p->append(SkRasterPipeline::parametric, sqrt);
     }
 
     if (!shaderIsOpaque) {
diff --git a/src/effects/SkToSRGBColorFilter.cpp b/src/effects/SkToSRGBColorFilter.cpp
index a9bd65c625..ba01c6b2c4 100644
--- a/src/effects/SkToSRGBColorFilter.cpp
+++ b/src/effects/SkToSRGBColorFilter.cpp
@@ -29,9 +29,7 @@ void SkToSRGBColorFilter::onAppendStages(SkRasterPipeline* p,
         p->append(SkRasterPipeline::from_srgb);
     } else if (fSrcColorSpace->isNumericalTransferFn(&srcFn)) {
         auto copy = alloc->make<SkColorSpaceTransferFn>(srcFn);
-        p->append(SkRasterPipeline::parametric_r, copy);
-        p->append(SkRasterPipeline::parametric_g, copy);
-        p->append(SkRasterPipeline::parametric_b, copy);
+        p->append(SkRasterPipeline::parametric, copy);
     } else {
         SkDEBUGFAIL("Looks like we got a table transfer function here, quite unexpectedly.");
         // TODO: If we really need to handle this, we can, but I don't think Ganesh does.
diff --git a/src/opts/SkRasterPipeline_opts.h b/src/opts/SkRasterPipeline_opts.h
index 1266970285..0dce9cfdb6 100644
--- a/src/opts/SkRasterPipeline_opts.h
+++ b/src/opts/SkRasterPipeline_opts.h
@@ -1483,26 +1483,24 @@ STAGE(byte_tables, const void* ctx) {  // TODO: rename Tables SkJumper_ByteTable
     a = from_byte(gather(tables->a, to_unorm(a, 255)));
 }
 
-SI F parametric(F v, const SkJumper_ParametricTransferFunction* ctx) {
-    F r = if_then_else(v <= ctx->D, mad(ctx->C, v, ctx->F)
-                                  , approx_powf(mad(ctx->A, v, ctx->B), ctx->G) + ctx->E);
-    return min(max(r, 0), 1.0f);  // Clamp to [0,1], with argument order mattering to handle NaN.
+STAGE(parametric, const SkJumper_ParametricTransferFunction* ctx) {
+    auto fn = [&](F v) {
+        F r = if_then_else(v <= ctx->D, mad(ctx->C, v, ctx->F)
+                                      , approx_powf(mad(ctx->A, v, ctx->B), ctx->G) + ctx->E);
+        // Clamp to [0,1], with argument order mattering to handle NaN.
+        // TODO: should we really be clamping here?
+        return min(max(r, 0), 1.0f);
+    };
+    r = fn(r);
+    g = fn(g);
+    b = fn(b);
 }
-STAGE(parametric_r, const SkJumper_ParametricTransferFunction* ctx) { r = parametric(r, ctx); }
-STAGE(parametric_g, const SkJumper_ParametricTransferFunction* ctx) { g = parametric(g, ctx); }
-STAGE(parametric_b, const SkJumper_ParametricTransferFunction* ctx) { b = parametric(b, ctx); }
-STAGE(parametric_a, const SkJumper_ParametricTransferFunction* ctx) { a = parametric(a, ctx); }
 
 STAGE(gamma, const float* G) {
     r = approx_powf(r, *G);
     g = approx_powf(g, *G);
     b = approx_powf(b, *G);
 }
-STAGE(gamma_dst, const float* G) {
-    dr = approx_powf(dr, *G);
-    dg = approx_powf(dg, *G);
-    db = approx_powf(db, *G);
-}
 
 STAGE(load_a8, const SkJumper_MemoryCtx* ctx) {
     auto ptr = ptr_at_xy<const uint8_t>(ctx, dx,dy);
@@ -3220,8 +3218,7 @@ static NotImplemented
         byte_tables,
         colorburn, colordodge, softlight, hue, saturation, color, luminosity,
         matrix_3x3, matrix_3x4, matrix_4x5, matrix_4x3,
-        parametric_r, parametric_g, parametric_b, parametric_a,
-        gamma, gamma_dst,
+        parametric, gamma,
         rgb_to_hsl, hsl_to_rgb,
         gauss_a_to_rgba,
         mirror_x, repeat_x,