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我有问题freetype和OpenGL。我只需要在单个纹理上绘制所有加载的符号。这里是:使用Freetype和OpenGL渲染字体
FT_Init_FreeType(&lib);
FT_New_Face(lib, "C:\\verdana.ttf", 0, &face);
FT_Set_Pixel_Sizes(face, 0, size);
auto ww = 256 * size;
auto hh = size;
std::vector<unsigned char> buffer(ww * hh, 0);
int off = 0;
for (int c = 0; c < 256; c++)
{
FT_UInt GlyphIndex;
GlyphIndex = FT_Get_Char_Index(face, c);
FT_Load_Char(face, GlyphIndex, FT_LOAD_RENDER);
FT_Bitmap bmp = face->glyph->bitmap;
int advance = (face->glyph->advance.x >> 6);
int bW = bmp.width;
int bH = bmp.rows;
for (int h = 0; h < bH; ++h) {
for (int w = 0; w < bW; ++w) {
buffer[h * bW + off + w] = bmp.buffer[w + bW * h];
}
}
off += advance;
}
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, ww, hh, 0, GL_ALPHA, GL_UNSIGNED_BYTE, &buffer[0]);
我尝试了很多方法来做到这一点。但我得到的是绝对黑色的纹理... 我的代码有什么问题?
您是否检查从FT_Init_FreeType,FT_New_Face等返回的错误代码?另外可能需要调用FT_Set_Char_Size。 – BDL 2014-12-03 11:52:02
我在代码的任何部分都没有发现错误。我用FT_Set_Pixel_Sizes设置字符大小。 – user3808059 2014-12-03 12:00:17
但是你也不检查错误。每个freetype函数都返回一个值,表示它是成功/失败的。例如:'error = FT_Init_FreeType(&library); if(error){failed; }' – BDL 2014-12-03 12:33:16