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現在、アンドロイドndk/openglプロジェクトで作業しています。私はフォントレンダリングライブラリとしてfreetypeを使用しようとしていますが、スクリーンにテキストをレンダリングすると奇妙なエラーが続きます。ここではいくつかのサンプルテキストに示しているものである:(注:下の1は "これがある" と言うことになっている)フリースタイルライブラリは三重テクスチャと奇妙なシンボルを与えます
セットアップ:
void TextRenderer::SetupGlyphs(std::string fontPath, int size){
__android_log_print(ANDROID_LOG_INFO, "SetupGlyphs", "Font location: %s", fontPath.c_str());
if(shadersInitialized == 0)
CreateShader();
glUseProgram(this->shader);
// FreeType
FT_Library ft;
if (FT_Init_FreeType(&ft))
__android_log_print(ANDROID_LOG_INFO, "SetupGlyphs", "ERROR::FREETYPE: Could not init FreeType Library.");
FT_Face face;
if (FT_New_Face(ft, fontPath.c_str(), 0, &face))
__android_log_print(ANDROID_LOG_INFO, "SetupGlyphs", "ERROR::FREETYPE: Failed to load font: %s", fontPath.c_str());
FT_Set_Pixel_Sizes(face, 0, size);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
for (GLubyte c = 0; c < 128; c++){
if(FT_Load_Char(face, c, FT_LOAD_RENDER)){
__android_log_print(ANDROID_LOG_INFO, "SetupGlyphs", "ERROR::FREETYPE: Failed to load Glyph");
continue;
}
GLuint texture;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glTexImage2D(
GL_TEXTURE_2D,
0,
GL_RGB,
face->glyph->bitmap.width,
face->glyph->bitmap.rows,
0,
GL_RGB,
GL_UNSIGNED_BYTE,
face->glyph->bitmap.buffer
);
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);
Character character = {
texture,
ivec2(face->glyph->bitmap.width, face->glyph->bitmap.rows),
ivec2(face->glyph->bitmap_left, face->glyph->bitmap_top),
static_cast<GLuint>(face->glyph->advance.x)
};
characters.insert(std::pair<GLchar, Character>(c, character));
}
glBindTexture(GL_TEXTURE_2D, 0);
FT_Done_Face(face);
FT_Done_FreeType(ft);
}
レンダリング:
void TextRenderer::RenderTexts()
{
if(shadersInitialized == 0)
CreateShader();
// Activate corresponding render state
glUseProgram(this->shader);
GLuint projectionLocation = glGetUniformLocation(this->shader, "projection");
glUniformMatrix4fv(projectionLocation, 1, GL_FALSE, projectionMatrix);
for (int i=0; i<projects.size(); i++) {
ProjectLabel project = projects.at(i);
glUniform3f(glGetUniformLocation(this->shader, "textColor"), project.textColor.x, project.textColor.y, project.textColor.z);
glActiveTexture(GL_TEXTURE0);
GLuint vertexBuffer;
glGenBuffers(1, &vertexBuffer);
/* Set up the VBO for our vertex data */
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0);
// Iterate through all characters
std::string::const_iterator c;
GLuint x = project.x;
for (c = project.text.begin(); c != project.text.end(); c++)
{
Character ch = characters[*c];
GLfloat xpos = x + ch.Bearing.x;
GLfloat ypos = project.y - (ch.Size.y - ch.Bearing.y);
GLfloat w = ch.Size.x;
GLfloat h = ch.Size.y;
// Update VBO for each character
GLfloat vertices[6*4] = {
xpos, ypos + h, 0.0, 0.0 ,
xpos, ypos, 0.0, 1.0 ,
xpos + w, ypos, 1.0, 1.0 ,
xpos, ypos + h, 0.0, 0.0 ,
xpos + w, ypos, 1.0, 1.0 ,
xpos + w, ypos + h, 1.0, 0.0
};
glBindTexture(GL_TEXTURE_2D, ch.TextureID);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_DYNAMIC_DRAW);
glDrawArrays(GL_TRIANGLES, 0, 6);
x += (ch.Advance/64); // Bitshift by 6 to get value in pixels (2^6 = 64 (divide amount of 1/64th pixels by 64 to get amount of pixels))
}
glDisableVertexAttribArray(0);
}
glBindTexture(GL_TEXTURE_2D, 0);
}