本文整理汇总了C++中VertexRange::isEmpty方法的典型用法代码示例。如果您正苦于以下问题：C++ VertexRange::isEmpty方法的具体用法？C++ VertexRange::isEmpty怎么用？C++ VertexRange::isEmpty使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类VertexRange的用法示例。
在下文中一共展示了VertexRange::isEmpty方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: drawText
void Font::drawText(vec2 pen, vec4 color, const char* text)
{
uint vertexCount = 0;
// Realize vertices for glyphs
{
const size_t length = std::strlen(text);
m_vertices.resize(length * 6);
for (const char* c = text; *c != '\0'; )
{
const uint32 codepoint = utf8::next<const char*>(c, text + length);
const Glyph* glyph = findGlyph(codepoint);
if (!glyph)
{
glyph = findGlyph(0xfffd);
if (!glyph)
continue;
}
pen = round(pen);
if (all(greaterThan(glyph->size, vec2(0.f))))
{
const Rect pa(pen + glyph->bearing - vec2(0.5f), glyph->size);
const Rect ta(glyph->offset + vec2(0.5f), glyph->size);
m_vertices[vertexCount + 0].texcoord = ta.position;
m_vertices[vertexCount + 0].position = pa.position;
m_vertices[vertexCount + 1].texcoord = ta.position + vec2(ta.size.x, 0.f);
m_vertices[vertexCount + 1].position = pa.position + vec2(pa.size.x, 0.f);
m_vertices[vertexCount + 2].texcoord = ta.position + ta.size;
m_vertices[vertexCount + 2].position = pa.position + pa.size;
m_vertices[vertexCount + 3] = m_vertices[vertexCount + 2];
m_vertices[vertexCount + 4].texcoord = ta.position + vec2(0.f, ta.size.y);
m_vertices[vertexCount + 4].position = pa.position + vec2(0.f, pa.size.y);
m_vertices[vertexCount + 5] = m_vertices[vertexCount + 0];
vertexCount += 6;
}
pen += vec2(glyph->advance, 0.f);
}
}
if (!vertexCount)
return;
VertexRange range = m_context.allocateVertices(vertexCount,
Vertex2ft2fv::format);
if (range.isEmpty())
{
logError("Failed to allocate vertices for text drawing");
return;
}
range.copyFrom(m_vertices.data());
m_pass.setUniformState(m_colorIndex, color);
m_pass.apply();
m_context.render(PrimitiveRange(TRIANGLE_LIST, range));
}