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

    41 

    42 #include "qtextureglyphcache_gl_p.h"

    43 #include "qpaintengineex_opengl2_p.h"

    44 

    45 #ifdef Q_WS_WIN

    46 extern Q_GUI_EXPORT bool qt_cleartype_enabled;

    47 #endif

    48 

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

    50     : QTextureGlyphCache(type, matrix)

    51     , ctx(context)

    52     , m_width(0)

    53     , m_height(0)

    54 {

    55     glGenFramebuffers(1, &m_fbo);

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

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

    58 }

    59 

    60 QGLTextureGlyphCache::~QGLTextureGlyphCache()

    61 {

    62     if (ctx) {

    63         QGLShareContextScope scope(ctx);

    64         glDeleteFramebuffers(1, &m_fbo);

    65 

    66         if (m_width || m_height)

    67             glDeleteTextures(1, &m_texture);

    68     }

    69 }

    70 

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

    72 {

    73     glGenTextures(1, &m_texture);

    74     glBindTexture(GL_TEXTURE_2D, m_texture);

    75 

    76     m_width = width;

    77     m_height = height;

    78 

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

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

    81         data[i] = 0;

    82 

    83     if (m_type == QFontEngineGlyphCache::Raster_RGBMask)

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

    85     else

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

    87 

    88     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

    89     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

    90 }

    91 

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

    93 {

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

    95     // ### resizeTextureData to fail

    96 

    97     int oldWidth = m_width;

    98     int oldHeight = m_height;

    99 

   100     GLuint oldTexture = m_texture;

   101     createTextureData(width, height);

   102 

   103     glBindFramebuffer(GL_FRAMEBUFFER_EXT, m_fbo);

   104 

   105     GLuint tmp_texture;

   106     glGenTextures(1, &tmp_texture);

   107     glBindTexture(GL_TEXTURE_2D, tmp_texture);

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

   109                  GL_RGBA, GL_UNSIGNED_BYTE, NULL);

   110     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

   111     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

   112     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

   113     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

   114     glBindTexture(GL_TEXTURE_2D, 0);

   115     glFramebufferTexture2D(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,

   116                            GL_TEXTURE_2D, tmp_texture, 0);

   117 

   118     glActiveTexture(GL_TEXTURE0 + QT_IMAGE_TEXTURE_UNIT);

   119     glBindTexture(GL_TEXTURE_2D, oldTexture);

   120 

   121     pex->transferMode(BrushDrawingMode);

   122 

   123     glDisable(GL_STENCIL_TEST);

   124     glDisable(GL_DEPTH_TEST);

   125     glDisable(GL_SCISSOR_TEST);

   126     glDisable(GL_BLEND);

   127 

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

   129 

   130     GLfloat* vertexCoordinateArray = pex->staticVertexCoordinateArray;

   131     vertexCoordinateArray[0] = -1.0f;

   132     vertexCoordinateArray[1] = -1.0f;

   133     vertexCoordinateArray[2] =  1.0f;

   134     vertexCoordinateArray[3] = -1.0f;

   135     vertexCoordinateArray[4] =  1.0f;

   136     vertexCoordinateArray[5] =  1.0f;

   137     vertexCoordinateArray[6] = -1.0f;

   138     vertexCoordinateArray[7] =  1.0f;

   139 

   140     GLfloat* textureCoordinateArray = pex->staticTextureCoordinateArray;

   141     textureCoordinateArray[0] = 0.0f;

   142     textureCoordinateArray[1] = 0.0f;

   143     textureCoordinateArray[2] = 1.0f;

   144     textureCoordinateArray[3] = 0.0f;

   145     textureCoordinateArray[4] = 1.0f;

   146     textureCoordinateArray[5] = 1.0f;

   147     textureCoordinateArray[6] = 0.0f;

   148     textureCoordinateArray[7] = 1.0f;

   149 

   150     pex->setVertexAttributePointer(QT_VERTEX_COORDS_ATTR, vertexCoordinateArray);

   151     pex->setVertexAttributePointer(QT_TEXTURE_COORDS_ATTR, textureCoordinateArray);

   152 

   153     pex->shaderManager->useBlitProgram();

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

   155 

   156     glDrawArrays(GL_TRIANGLE_FAN, 0, 4);

   157 

   158     glBindTexture(GL_TEXTURE_2D, m_texture);

   159 

   160 #ifdef QT_OPENGL_ES_2

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

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

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

   164 

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

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

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

   168 

   169     glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, oldWidth, oldHeight,

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

   171 #else

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

   173 #endif

   174 

   175     glFramebufferRenderbuffer(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,

   176                               GL_RENDERBUFFER_EXT, 0);

   177     glDeleteTextures(1, &tmp_texture);

   178     glDeleteTextures(1, &oldTexture);

   179 

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

   181 

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

   183     pex->updateClipScissorTest();

   184 }

   185 

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

   187 {

   188     QImage mask = textureMapForGlyph(glyph);

   189     const int maskWidth = mask.width();

   190     const int maskHeight = mask.height();

   191 

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

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

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

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

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

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

   198         }

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

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

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

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

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

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

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

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

   207                 uchar b = src[x];

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

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

   210             }

   211         }

   212     }

   213 

   214     glBindTexture(GL_TEXTURE_2D, m_texture);

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

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

   217     } else {

   218 #ifdef QT_OPENGL_ES2

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

   220 #else

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

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

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

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

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

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

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

   228         // time.

   229 

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

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

   232 #endif

   233     }

   234 }

   235 

   236 int QGLTextureGlyphCache::glyphMargin() const

   237 {

   238 #if defined(Q_WS_MAC)

   239     return 2;

   240 #elif defined (Q_WS_X11)

   241     return 0;

   242 #else

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

   244 #endif

   245 }