bc1_transparency.cpp File Reference

#include "gm/gm.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkImage.h"
#include "include/core/SkTextureCompressionType.h"
#include "include/gpu/GrDirectContext.h"
#include "include/gpu/GrRecordingContext.h"
#include "include/gpu/ganesh/SkImageGanesh.h"
#include "src/core/SkCompressedDataUtils.h"
#include "src/gpu/ganesh/GrCaps.h"
#include "src/gpu/ganesh/GrImageContextPriv.h"
#include "src/gpu/ganesh/image/SkImage_GaneshBase.h"
#include "src/image/SkImage_Base.h"
#include "tools/gpu/ProxyUtils.h"

Go to the source code of this file.

Classes
struct	BC1Block
class	skiagm::BC1TransparencyGM

Namespaces
namespace	skiagm

Functions
static int	num_4x4_blocks (int size)
static uint16_t	to565 (SkColor col)
static void	create_BC1_block (BC1Block *block, bool transparent)
static sk_sp< SkData >	make_compressed_data ()
static sk_sp< SkImage >	data_to_img (GrDirectContext *direct, sk_sp< SkData > data, SkTextureCompressionType compression)
static void	draw_image (SkCanvas *canvas, sk_sp< SkImage > image, int x, int y)

Variables
constexpr int	kImgWidth = 16
constexpr int	kImgHeight = 8
constexpr int	kPad = 4

Function Documentation

create_BC1_block()

static void create_BC1_block ( BC1Block *  block, bool  transparent  )

static

Definition at line 59 of file bc1_transparency.cpp.

                                                                {
    unsigned int byte;
 
    if (transparent) {
        block->fColor0 = to565(SK_ColorBLACK);
        block->fColor1 = to565(SK_ColorWHITE);
        SkASSERT(block->fColor0 <= block->fColor1); // this signals a transparent block
        // opaque black (col0), medium grey (col2), transparent black (col3), white (col1).
        byte = (0x0 << 0) | (0x2 << 2) | (0x3 << 4) | (0x1 << 6);
    } else {
        block->fColor0 = to565(SK_ColorWHITE);
        block->fColor1 = to565(SK_ColorBLACK);
        SkASSERT(block->fColor0 > block->fColor1); // this signals an opaque block
        // opaque black (col1), dark grey (col3), light grey (col2), white (col0)
        byte = (0x1 << 0) | (0x3 << 2) | (0x2 << 4) | (0x0 << 6);
    }
 
    block->fIndices = (byte << 24) | (byte << 16) | (byte << 8) | byte;
}

data_to_img()

static sk_sp< SkImage > data_to_img ( GrDirectContext *  direct, sk_sp< SkData >  data, SkTextureCompressionType  compression  )

static

Definition at line 106 of file bc1_transparency.cpp.

                                                                        {
    if (direct) {
        return SkImages::TextureFromCompressedTextureData(
                direct, std::move(data), kImgWidth, kImgHeight, compression, skgpu::Mipmapped::kNo);
    } else {
        return SkImages::RasterFromCompressedTextureData(
                std::move(data), kImgWidth, kImgHeight, compression);
    }
}

draw_image()

static void draw_image ( SkCanvas *  canvas, sk_sp< SkImage >  image, int  x, int  y  )

static

Definition at line 117 of file bc1_transparency.cpp.

                                                                             {
 
    bool isCompressed = false;
    if (image && image->isTextureBacked()) {
        const GrCaps* caps = as_IB(image)->context()->priv().caps();
        GrTextureProxy* proxy = sk_gpu_test::GetTextureImageProxy(image.get(),
                                                                  canvas->recordingContext());
        isCompressed = caps->isFormatCompressed(proxy->backendFormat());
    }
 
    canvas->drawImage(image, x, y);
 
    if (!isCompressed) {
        SkRect r = SkRect::MakeXYWH(x, y, kImgWidth, kImgHeight);
        r.outset(1.0f, 1.0f);
 
        SkPaint redStroke;
        redStroke.setColor(SK_ColorRED);
        redStroke.setStyle(SkPaint::kStroke_Style);
        redStroke.setStrokeWidth(2.0f);
 
        canvas->drawRect(r, redStroke);
    }
}

make_compressed_data()

static sk_sp< SkData > make_compressed_data ( )

static

Definition at line 81 of file bc1_transparency.cpp.

                                            {
    SkISize dim{ kImgWidth, kImgHeight };
 
    size_t totalSize = SkCompressedDataSize(SkTextureCompressionType::kBC1_RGB8_UNORM, dim,
                                            nullptr, false);
 
    sk_sp<SkData> tmp = SkData::MakeUninitialized(totalSize);
    BC1Block* dstBlocks = reinterpret_cast<BC1Block*>(tmp->writable_data());
 
    BC1Block transBlock, opaqueBlock;
    create_BC1_block(&transBlock, true);
    create_BC1_block(&opaqueBlock, false);
 
    int numXBlocks = num_4x4_blocks(kImgWidth);
    int numYBlocks = num_4x4_blocks(kImgHeight);
 
    for (int y = 0; y < numYBlocks; ++y) {
        for (int x = 0; x < numXBlocks; ++x) {
            dstBlocks[y*numXBlocks + x] = (y < numYBlocks/2) ? transBlock : opaqueBlock;
        }
    }
 
    return tmp;
}

num_4x4_blocks()

static int num_4x4_blocks ( int  size )

static

Definition at line 32 of file bc1_transparency.cpp.

                                    {
    return ((size + 3) & ~3) >> 2;
}

to565()

static uint16_t to565 ( SkColor  col )

static

Definition at line 36 of file bc1_transparency.cpp.

                                   {
    int r5 = SkMulDiv255Round(31, SkColorGetR(col));
    int g6 = SkMulDiv255Round(63, SkColorGetG(col));
    int b5 = SkMulDiv255Round(31, SkColorGetB(col));
 
    return (r5 << 11) | (g6 << 5) | b5;
}

Variable Documentation

kImgHeight

constexpr int kImgHeight = 8

constexpr

Definition at line 23 of file bc1_transparency.cpp.

kImgWidth

constexpr int kImgWidth = 16

constexpr

Definition at line 22 of file bc1_transparency.cpp.

kPad

constexpr int kPad = 4

constexpr

Definition at line 24 of file bc1_transparency.cpp.