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    40 ****************************************************************************/

    41 

    42 #include "qtextureglyphcache_gl_p.h"

    43 #include "qpaintengineex_opengl2_p.h"

    44 

    45 QT_BEGIN_NAMESPACE

    46 

    47 #ifdef Q_WS_WIN

    48 extern Q_GUI_EXPORT bool qt_cleartype_enabled;

    49 #endif

    50 

    51 QGLTextureGlyphCache::QGLTextureGlyphCache(QGLContext *context, QFontEngineGlyphCache::Type type, const QTransform &matrix)

    52     : QTextureGlyphCache(type, matrix)

    53     , ctx(context)

    54     , m_width(0)

    55     , m_height(0)

    56 {

    57     glGenFramebuffers(1, &m_fbo);

    58     connect(QGLSignalProxy::instance(), SIGNAL(aboutToDestroyContext(const QGLContext*)),

    59             SLOT(contextDestroyed(const QGLContext*)));

    60 }

    61 

    62 QGLTextureGlyphCache::~QGLTextureGlyphCache()

    63 {

    64     if (ctx) {

    65         QGLShareContextScope scope(ctx);

    66         glDeleteFramebuffers(1, &m_fbo);

    67 

    68         if (m_width || m_height)

    69             glDeleteTextures(1, &m_texture);

    70     }

    71 }

    72 

    73 void QGLTextureGlyphCache::createTextureData(int width, int height)

    74 {

    75     glGenTextures(1, &m_texture);

    76     glBindTexture(GL_TEXTURE_2D, m_texture);

    77 

    78     m_width = width;

    79     m_height = height;

    80 

    81     QVarLengthArray<uchar> data(width * height);

    82     for (int i = 0; i < data.size(); ++i)

    83         data[i] = 0;

    84 

    85     if (m_type == QFontEngineGlyphCache::Raster_RGBMask)

    86         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, &data[0]);

    87     else

    88         glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, &data[0]);

    89 

    90     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

    91     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

    92 }

    93 

    94 void QGLTextureGlyphCache::resizeTextureData(int width, int height)

    95 {

    96     // ### the QTextureGlyphCache API needs to be reworked to allow

    97     // ### resizeTextureData to fail

    98 

    99     int oldWidth = m_width;

   100     int oldHeight = m_height;

   101 

   102     GLuint oldTexture = m_texture;

   103     createTextureData(width, height);

   104 

   105     glBindFramebuffer(GL_FRAMEBUFFER_EXT, m_fbo);

   106 

   107     GLuint tmp_texture;

   108     glGenTextures(1, &tmp_texture);

   109     glBindTexture(GL_TEXTURE_2D, tmp_texture);

   110     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, oldWidth, oldHeight, 0,

   111                  GL_RGBA, GL_UNSIGNED_BYTE, NULL);

   112     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

   113     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

   114     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

   115     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

   116     glBindTexture(GL_TEXTURE_2D, 0);

   117     glFramebufferTexture2D(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,

   118                            GL_TEXTURE_2D, tmp_texture, 0);

   119 

   120     glActiveTexture(GL_TEXTURE0 + QT_IMAGE_TEXTURE_UNIT);

   121     glBindTexture(GL_TEXTURE_2D, oldTexture);

   122 

   123     pex->transferMode(BrushDrawingMode);

   124 

   125     glDisable(GL_STENCIL_TEST);

   126     glDisable(GL_DEPTH_TEST);

   127     glDisable(GL_SCISSOR_TEST);

   128     glDisable(GL_BLEND);

   129 

   130     glViewport(0, 0, oldWidth, oldHeight);

   131 

   132     GLfloat* vertexCoordinateArray = pex->staticVertexCoordinateArray;

   133     vertexCoordinateArray[0] = -1.0f;

   134     vertexCoordinateArray[1] = -1.0f;

   135     vertexCoordinateArray[2] =  1.0f;

   136     vertexCoordinateArray[3] = -1.0f;

   137     vertexCoordinateArray[4] =  1.0f;

   138     vertexCoordinateArray[5] =  1.0f;

   139     vertexCoordinateArray[6] = -1.0f;

   140     vertexCoordinateArray[7] =  1.0f;

   141 

   142     GLfloat* textureCoordinateArray = pex->staticTextureCoordinateArray;

   143     textureCoordinateArray[0] = 0.0f;

   144     textureCoordinateArray[1] = 0.0f;

   145     textureCoordinateArray[2] = 1.0f;

   146     textureCoordinateArray[3] = 0.0f;

   147     textureCoordinateArray[4] = 1.0f;

   148     textureCoordinateArray[5] = 1.0f;

   149     textureCoordinateArray[6] = 0.0f;

   150     textureCoordinateArray[7] = 1.0f;

   151 

   152     pex->setVertexAttributePointer(QT_VERTEX_COORDS_ATTR, vertexCoordinateArray);

   153     pex->setVertexAttributePointer(QT_TEXTURE_COORDS_ATTR, textureCoordinateArray);

   154 

   155     pex->shaderManager->useBlitProgram();

   156     pex->shaderManager->blitProgram()->setUniformValue("imageTexture", QT_IMAGE_TEXTURE_UNIT);

   157 

   158     glDrawArrays(GL_TRIANGLE_FAN, 0, 4);

   159 

   160     glBindTexture(GL_TEXTURE_2D, m_texture);

   161 

   162 #ifdef QT_OPENGL_ES_2

   163     QDataBuffer<uchar> buffer(4*oldWidth*oldHeight);

   164     buffer.resize(4*oldWidth*oldHeight);

   165     glReadPixels(0, 0, oldWidth, oldHeight, GL_RGBA, GL_UNSIGNED_BYTE, buffer.data());

   166 

   167     // do an in-place conversion from GL_RGBA to GL_ALPHA

   168     for (int i=0; i<oldWidth*oldHeight; ++i)

   169         buffer.data()[i] = buffer.at(4*i + 3);

   170 

   171     glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, oldWidth, oldHeight,

   172                     GL_ALPHA, GL_UNSIGNED_BYTE, buffer.data());

   173 #else

   174     glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, oldWidth, oldHeight);

   175 #endif

   176 

   177     glFramebufferRenderbuffer(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,

   178                               GL_RENDERBUFFER_EXT, 0);

   179     glDeleteTextures(1, &tmp_texture);

   180     glDeleteTextures(1, &oldTexture);

   181 

   182     glBindFramebuffer(GL_FRAMEBUFFER_EXT, ctx->d_ptr->current_fbo);

   183 

   184     glViewport(0, 0, pex->width, pex->height);

   185     pex->updateClipScissorTest();

   186 }

   187 

   188 void QGLTextureGlyphCache::fillTexture(const Coord &c, glyph_t glyph)

   189 {

   190     QImage mask = textureMapForGlyph(glyph);

   191     const int maskWidth = mask.width();

   192     const int maskHeight = mask.height();

   193 

   194     if (mask.format() == QImage::Format_Mono) {

   195         mask = mask.convertToFormat(QImage::Format_Indexed8);

   196         for (int y = 0; y < maskHeight; ++y) {

   197             uchar *src = (uchar *) mask.scanLine(y);

   198             for (int x = 0; x < maskWidth; ++x)

   199                 src[x] = -src[x]; // convert 0 and 1 into 0 and 255

   200         }

   201     } else if (mask.format() == QImage::Format_RGB32) {

   202         // Make the alpha component equal to the average of the RGB values.

   203         // This is needed when drawing sub-pixel antialiased text on translucent targets.

   204         for (int y = 0; y < maskHeight; ++y) {

   205             quint32 *src = (quint32 *) mask.scanLine(y);

   206             for (int x = 0; x < maskWidth; ++x) {

   207                 uchar r = src[x] >> 16;

   208                 uchar g = src[x] >> 8;

   209                 uchar b = src[x];

   210                 quint32 avg = (quint32(r) + quint32(g) + quint32(b) + 1) / 3; // "+1" for rounding.

   211                 src[x] = (src[x] & 0x00ffffff) | (avg << 24);

   212             }

   213         }

   214     }

   215 

   216     glBindTexture(GL_TEXTURE_2D, m_texture);

   217     if (mask.format() == QImage::Format_RGB32) {

   218         glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, GL_BGRA, GL_UNSIGNED_BYTE, mask.bits());

   219     } else {

   220 #ifdef QT_OPENGL_ES2

   221         glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, GL_ALPHA, GL_UNSIGNED_BYTE, mask.bits());

   222 #else

   223         // glTexSubImage2D() might cause some garbage to appear in the texture if the mask width is

   224         // not a multiple of four bytes. The bug appeared on a computer with 32-bit Windows Vista

   225         // and nVidia GeForce 8500GT. GL_UNPACK_ALIGNMENT is set to four bytes, 'mask' has a

   226         // multiple of four bytes per line, and most of the glyph shows up correctly in the

   227         // texture, which makes me think that this is a driver bug.

   228         // One workaround is to make sure the mask width is a multiple of four bytes, for instance

   229         // by converting it to a format with four bytes per pixel. Another is to copy one line at a

   230         // time.

   231 

   232         for (int i = 0; i < maskHeight; ++i)

   233             glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y + i, maskWidth, 1, GL_ALPHA, GL_UNSIGNED_BYTE, mask.scanLine(i));

   234 #endif

   235     }

   236 }

   237 

   238 int QGLTextureGlyphCache::glyphMargin() const

   239 {

   240 #if defined(Q_WS_MAC)

   241     return 2;

   242 #elif defined (Q_WS_X11)

   243     return 0;

   244 #else

   245     return m_type == QFontEngineGlyphCache::Raster_RGBMask ? 2 : 0;

   246 #endif

   247 }

   248 

   249 QT_END_NAMESPACE