Convert bitmaps to sRGB/scRGB when they have a color profile

This change also fixes an issue with RGBA16F bitmaps when modulated
with a color (for instance by setting an alpha on the Paint object).

The color space conversion is currently done entirely in the shader,
by doing these operations in order:

1. Sample the texture
2. Un-premultiply alpha
3. Apply the EOTF
4. Multiply by the 3x3 color space matrix
5. Apply the OETF
6. Premultiply alpha

Optimizations:
- Steps 2 & 6 are skipped for opaque (common) bitmaps
- Step 3 is skipped when the color space's EOTF is close
  to sRGB (Display P3 for instance). Instead, we use
  a hardware sRGB fetch (when the GPU supports it)
- When step 3 is necessary, we use one of four standard
  EOTF implementations, to save cycles when possible:
  + Linear (doesn't do anything)
  + Full parametric (ICC parametric curve type 4 as defined
    in ICC.1:2004-10, section 10.15)
  + Limited parametric (ICC parametric curve type 3)
  + Gamma (ICC parametric curve type 0)

Color space conversion could be done using texture samplers
instead, for instance 3D LUTs, with or without transfer
functions baked in, or 1D LUTs for transfer functions. This
would result in dependent texture fetches which may or may
not be an advantage over an ALU based implementation. The
current solution favor the use of ALUs to save precious
bandwidth.

Test: CtsUiRenderingTests, CtsGraphicsTests
Bug: 32984164
Change-Id: I10bc3db515e13973b45220f129c66b23f0f7f8fe

1 files changed, 35 insertions, 18 deletions

diff --git a/libs/hwui/Program.h b/libs/hwui/Program.h
index 5c8f8e93fa3d..2becfcb709c3 100644
--- a/libs/hwui/Program.h
+++ b/libs/hwui/Program.h
@@ -28,6 +28,7 @@
 #include "FloatColor.h"
 #include "Matrix.h"
 #include "Properties.h"
+#include "utils/Color.h"
 
 namespace android {
 namespace uirenderer {
@@ -56,11 +57,11 @@ namespace uirenderer {
 #define PROGRAM_KEY_BITMAP_NPOT         0x80
 #define PROGRAM_KEY_BITMAP_EXTERNAL    0x100
 
-#define PROGRAM_KEY_SWAP_SRC_DST      0x2000
-
 #define PROGRAM_KEY_BITMAP_WRAPS_MASK  0x600
 #define PROGRAM_KEY_BITMAP_WRAPT_MASK 0x1800
 
+#define PROGRAM_KEY_SWAP_SRC_DST_SHIFT 13
+
 // Encode the xfermodes on 6 bits
 #define PROGRAM_MAX_XFERMODE 0x1f
 #define PROGRAM_XFERMODE_SHADER_SHIFT 26
@@ -89,6 +90,10 @@ namespace uirenderer {
 #define PROGRAM_HAS_GAMMA_CORRECTION 44
 #define PROGRAM_HAS_LINEAR_TEXTURE 45
 
+#define PROGRAM_HAS_COLOR_SPACE_CONVERSION 46
+#define PROGRAM_TRANSFER_FUNCTION 47 // 2 bits for transfer function
+#define PROGRAM_HAS_TRANSLUCENT_CONVERSION 49
+
 ///////////////////////////////////////////////////////////////////////////////
 // Types
 ///////////////////////////////////////////////////////////////////////////////
@@ -105,13 +110,13 @@ typedef uint64_t programid;
  * A ProgramDescription must be used in conjunction with a ProgramCache.
  */
 struct ProgramDescription {
-    enum class ColorFilterMode {
+    enum class ColorFilterMode : int8_t {
         None = 0,
         Matrix,
         Blend
     };
 
-    enum Gradient {
+    enum Gradient : int8_t {
         kGradientLinear = 0,
         kGradientCircular,
         kGradientSweep
@@ -168,6 +173,11 @@ struct ProgramDescription {
     // Set when sampling an image in linear space
     bool hasLinearTexture;
 
+    bool hasColorSpaceConversion;
+    TransferFunctionType transferFunction;
+    // Indicates whether the bitmap to convert between color spaces is translucent
+    bool hasTranslucentConversion;
+
     /**
      * Resets this description. All fields are reset back to the default
      * values they hold after building a new instance.
@@ -210,6 +220,10 @@ struct ProgramDescription {
 
         hasGammaCorrection = false;
         hasLinearTexture = false;
+
+        hasColorSpaceConversion = false;
+        transferFunction = TransferFunctionType::None;
+        hasTranslucentConversion = false;
     }
 
     /**
@@ -263,24 +277,27 @@ struct ProgramDescription {
                 break;
             case ColorFilterMode::Blend:
                 key |= PROGRAM_KEY_COLOR_BLEND;
-                key |= ((int)colorMode & PROGRAM_MAX_XFERMODE) << PROGRAM_XFERMODE_COLOR_OP_SHIFT;
+                key |= ((int) colorMode & PROGRAM_MAX_XFERMODE) << PROGRAM_XFERMODE_COLOR_OP_SHIFT;
                 break;
             case ColorFilterMode::None:
                 break;
         }
-        key |= ((int)framebufferMode & PROGRAM_MAX_XFERMODE) << PROGRAM_XFERMODE_FRAMEBUFFER_SHIFT;
-        if (swapSrcDst) key |= PROGRAM_KEY_SWAP_SRC_DST;
-        if (modulate) key |= programid(0x1) << PROGRAM_MODULATE_SHIFT;
-        if (hasVertexAlpha) key |= programid(0x1) << PROGRAM_HAS_VERTEX_ALPHA_SHIFT;
-        if (useShadowAlphaInterp) key |= programid(0x1) << PROGRAM_USE_SHADOW_ALPHA_INTERP_SHIFT;
-        if (hasExternalTexture) key |= programid(0x1) << PROGRAM_HAS_EXTERNAL_TEXTURE_SHIFT;
-        if (hasTextureTransform) key |= programid(0x1) << PROGRAM_HAS_TEXTURE_TRANSFORM_SHIFT;
-        if (isSimpleGradient) key |= programid(0x1) << PROGRAM_IS_SIMPLE_GRADIENT;
-        if (hasColors) key |= programid(0x1) << PROGRAM_HAS_COLORS;
-        if (hasDebugHighlight) key |= programid(0x1) << PROGRAM_HAS_DEBUG_HIGHLIGHT;
-        if (hasRoundRectClip) key |= programid(0x1) << PROGRAM_HAS_ROUND_RECT_CLIP;
-        if (hasGammaCorrection) key |= programid(0x1) << PROGRAM_HAS_GAMMA_CORRECTION;
-        if (hasLinearTexture) key |= programid(0x1) << PROGRAM_HAS_LINEAR_TEXTURE;
+        key |= ((int) framebufferMode & PROGRAM_MAX_XFERMODE) << PROGRAM_XFERMODE_FRAMEBUFFER_SHIFT;
+        key |= programid(swapSrcDst) << PROGRAM_KEY_SWAP_SRC_DST_SHIFT;
+        key |= programid(modulate) << PROGRAM_MODULATE_SHIFT;
+        key |= programid(hasVertexAlpha) << PROGRAM_HAS_VERTEX_ALPHA_SHIFT;
+        key |= programid(useShadowAlphaInterp) << PROGRAM_USE_SHADOW_ALPHA_INTERP_SHIFT;
+        key |= programid(hasExternalTexture) << PROGRAM_HAS_EXTERNAL_TEXTURE_SHIFT;
+        key |= programid(hasTextureTransform) << PROGRAM_HAS_TEXTURE_TRANSFORM_SHIFT;
+        key |= programid(isSimpleGradient) << PROGRAM_IS_SIMPLE_GRADIENT;
+        key |= programid(hasColors) << PROGRAM_HAS_COLORS;
+        key |= programid(hasDebugHighlight) << PROGRAM_HAS_DEBUG_HIGHLIGHT;
+        key |= programid(hasRoundRectClip) << PROGRAM_HAS_ROUND_RECT_CLIP;
+        key |= programid(hasGammaCorrection) << PROGRAM_HAS_GAMMA_CORRECTION;
+        key |= programid(hasLinearTexture) << PROGRAM_HAS_LINEAR_TEXTURE;
+        key |= programid(hasColorSpaceConversion) << PROGRAM_HAS_COLOR_SPACE_CONVERSION;
+        key |= programid(transferFunction) << PROGRAM_TRANSFER_FUNCTION;
+        key |= programid(hasTranslucentConversion) << PROGRAM_HAS_TRANSLUCENT_CONVERSION;
         return key;
     }