bool SkPixmap::computeIsOpaque()

in src/core/SkPixmap.cpp [592:756]
164 lines of code
61 McCabe index (conditional complexity)

bool SkPixmap::computeIsOpaque() const {
    const int height = this->height();
    const int width = this->width();

    switch (this->colorType()) {
        case kAlpha_8_SkColorType: {
            unsigned a = 0xFF;
            for (int y = 0; y < height; ++y) {
                const uint8_t* row = this->addr8(0, y);
                for (int x = 0; x < width; ++x) {
                    a &= row[x];
                }
                if (0xFF != a) {
                    return false;
                }
            }
            return true;
        }
        case kA16_unorm_SkColorType: {
            unsigned a = 0xFFFF;
            for (int y = 0; y < height; ++y) {
                const uint16_t* row = this->addr16(0, y);
                for (int x = 0; x < width; ++x) {
                    a &= row[x];
                }
                if (0xFFFF != a) {
                    return false;
                }
            }
            return true;
        }
        case kA16_float_SkColorType: {
            for (int y = 0; y < height; ++y) {
                const SkHalf* row = this->addr16(0, y);
                for (int x = 0; x < width; ++x) {
                    if (row[x] < SK_Half1) {
                        return false;
                    }
                }
            }
            return true;
        }
        case kRGB_565_SkColorType:
        case kGray_8_SkColorType:
        case kR8G8_unorm_SkColorType:
        case kR16G16_unorm_SkColorType:
        case kR16G16_float_SkColorType:
        case kRGB_888x_SkColorType:
        case kRGB_101010x_SkColorType:
        case kBGR_101010x_SkColorType:
        case kRGB_F16F16F16x_SkColorType:
        case kBGR_101010x_XR_SkColorType:
        case kR8_unorm_SkColorType:
            return true;
        case kARGB_4444_SkColorType: {
            unsigned c = 0xFFFF;
            for (int y = 0; y < height; ++y) {
                const SkPMColor16* row = this->addr16(0, y);
                for (int x = 0; x < width; ++x) {
                    c &= row[x];
                }
                if (0xF != SkGetPackedA4444(c)) {
                    return false;
                }
            }
            return true;
        }
        case kBGRA_8888_SkColorType:
        case kRGBA_8888_SkColorType:
        case kSRGBA_8888_SkColorType: {
            SkPMColor c = (SkPMColor)~0;
            for (int y = 0; y < height; ++y) {
                const SkPMColor* row = this->addr32(0, y);
                for (int x = 0; x < width; ++x) {
                    c &= row[x];
                }
                if (0xFF != SkGetPackedA32(c)) {
                    return false;
                }
            }
            return true;
        }
        case kRGBA_F16Norm_SkColorType:
        case kRGBA_F16_SkColorType: {
            const SkHalf* row = (const SkHalf*)this->addr();
            for (int y = 0; y < height; ++y) {
                for (int x = 0; x < width; ++x) {
                    if (row[4 * x + 3] < SK_Half1) {
                        return false;
                    }
                }
                row += this->rowBytes() >> 1;
            }
            return true;
        }
        case kRGBA_F32_SkColorType: {
            const float* row = (const float*)this->addr();
            for (int y = 0; y < height; ++y) {
                for (int x = 0; x < width; ++x) {
                    if (row[4 * x + 3] < 1.0f) {
                        return false;
                    }
                }
                row += this->rowBytes() >> 2;
            }
            return true;
        }
        case kRGBA_1010102_SkColorType:
        case kBGRA_1010102_SkColorType: {
            uint32_t c = ~0;
            for (int y = 0; y < height; ++y) {
                const uint32_t* row = this->addr32(0, y);
                for (int x = 0; x < width; ++x) {
                    c &= row[x];
                }
                if (0b11 != c >> 30) {
                    return false;
                }
            }
            return true;
        }
        case kBGRA_10101010_XR_SkColorType:{
            static constexpr uint64_t kOne = 510 + 384;
            for (int y = 0; y < height; ++y) {
                const uint64_t* row = this->addr64(0, y);
                for (int x = 0; x < width; ++x) {
                    if ((row[x] >> 54) < kOne) {
                        return false;
                    }
                }
            }
            return true;
        }
        case kRGBA_10x6_SkColorType: {
            uint16_t acc = 0xFFC0;  // Ignore bottom six bits
            for (int y = 0; y < height; ++y) {
                const uint64_t* row = this->addr64(0, y);
                for (int x = 0; x < width; ++x) {
                    acc &= (row[x] >> 48);
                }
                if (0xFFC0 != acc) {
                    return false;
                }
            }
            return true;
        }
        case kR16G16B16A16_unorm_SkColorType: {
            uint16_t acc = 0xFFFF;
            for (int y = 0; y < height; ++y) {
                const uint64_t* row = this->addr64(0, y);
                for (int x = 0; x < width; ++x) {
                    acc &= (row[x] >> 48);
                }
                if (0xFFFF != acc) {
                    return false;
                }
            }
            return true;
        }
        case kUnknown_SkColorType:
            SkDEBUGFAIL("");
            break;
    }
    return false;
}