Add support for half float alpha textures.
This allows us to create distance field textures with better precision,
which may help text quality.
BUG=skia:3103
Review URL: https://codereview.chromium.org/762923003
diff --git a/tests/FloatingPointTextureTest.cpp b/tests/FloatingPointTextureTest.cpp
index e058c11..d6074b9 100644
--- a/tests/FloatingPointTextureTest.cpp
+++ b/tests/FloatingPointTextureTest.cpp
@@ -17,10 +17,12 @@
#include "GrContext.h"
#include "GrTexture.h"
#include "GrContextFactory.h"
+
#include "SkGpuDevice.h"
+#include "SkHalf.h"
static const int DEV_W = 100, DEV_H = 100;
-static const int FP_CONTROL_ARRAY_SIZE = DEV_W * DEV_H * sizeof(float);
+static const int FP_CONTROL_ARRAY_SIZE = DEV_W * DEV_H * 4;
static const float kMaxIntegerRepresentableInSPFloatingPoint = 16777216; // 2 ^ 24
static const SkIRect DEV_RECT = SkIRect::MakeWH(DEV_W, DEV_H);
@@ -77,4 +79,59 @@
}
}
+static const int HALF_CONTROL_ARRAY_SIZE = DEV_W * DEV_H;
+
+DEF_GPUTEST(HalfFloatTextureTest, reporter, factory) {
+ SkHalf controlPixelData[HALF_CONTROL_ARRAY_SIZE];
+ SkHalf readBuffer[HALF_CONTROL_ARRAY_SIZE];
+ for (int i = 0; i < HALF_CONTROL_ARRAY_SIZE; i += 4) {
+ controlPixelData[i] = SK_HalfMin;
+ controlPixelData[i + 1] = SK_HalfMax;
+ controlPixelData[i + 2] = SK_HalfEpsilon;
+ controlPixelData[i + 3] = 0x6800; // 2^11
+ }
+
+ for (int origin = 0; origin < 2; ++origin) {
+ int glCtxTypeCnt = 1;
+ glCtxTypeCnt = GrContextFactory::kGLContextTypeCnt;
+ for (int glCtxType = 0; glCtxType < glCtxTypeCnt; ++glCtxType) {
+ GrSurfaceDesc desc;
+ desc.fFlags = kRenderTarget_GrSurfaceFlag;
+ desc.fWidth = DEV_W;
+ desc.fHeight = DEV_H;
+ desc.fConfig = kAlpha_half_GrPixelConfig;
+ desc.fOrigin = 0 == origin ?
+ kTopLeft_GrSurfaceOrigin : kBottomLeft_GrSurfaceOrigin;
+
+ GrContext* context = NULL;
+ GrContextFactory::GLContextType type =
+ static_cast<GrContextFactory::GLContextType>(glCtxType);
+ if (!GrContextFactory::IsRenderingGLContext(type)) {
+ continue;
+ }
+ context = factory->get(type);
+ if (NULL == context){
+ continue;
+ }
+
+ SkAutoTUnref<GrTexture> fpTexture(context->createUncachedTexture(desc,
+ NULL,
+ 0));
+
+ // 16-bit floating point textures are NOT supported everywhere
+ if (NULL == fpTexture) {
+ continue;
+ }
+
+ // write square
+ fpTexture->writePixels(0, 0, DEV_W, DEV_H, desc.fConfig, controlPixelData, 0);
+ fpTexture->readPixels(0, 0, DEV_W, DEV_H, desc.fConfig, readBuffer, 0);
+ for (int j = 0; j < HALF_CONTROL_ARRAY_SIZE; ++j) {
+ SkASSERT(readBuffer[j] == controlPixelData[j]);
+ REPORTER_ASSERT(reporter, readBuffer[j] == controlPixelData[j]);
+ }
+ }
+ }
+}
+
#endif