ImFont::RenderText() better vertical clipping for large amount of text (for #200)

This commit is contained in:
ocornut 2015-06-18 23:08:42 -06:00
parent 324b1c2a28
commit 84987ac3e0

135
imgui.cpp
View File

@ -10023,21 +10023,25 @@ void ImFont::RenderText(float size, ImVec2 pos, ImU32 col, const ImVec4& clip_re
if (!text_end) if (!text_end)
text_end = text_begin + strlen(text_begin); text_end = text_begin + strlen(text_begin);
const float scale = size / FontSize;
const float line_height = FontSize * scale;
// Align to be pixel perfect // Align to be pixel perfect
pos.x = (float)(int)pos.x + DisplayOffset.x; pos.x = (float)(int)pos.x + DisplayOffset.x;
pos.y = (float)(int)pos.y + DisplayOffset.y; pos.y = (float)(int)pos.y + DisplayOffset.y;
float x = pos.x; float x = pos.x;
float y = pos.y; float y = pos.y;
if (y > clip_rect.w)
return;
const float scale = size / FontSize;
const float line_height = FontSize * scale;
const bool word_wrap_enabled = (wrap_width > 0.0f); const bool word_wrap_enabled = (wrap_width > 0.0f);
const char* word_wrap_eol = NULL; const char* word_wrap_eol = NULL;
ImDrawVert* out_vertices = draw_list->vtx_write; ImDrawVert* out_vertices = draw_list->vtx_write;
const char* s = text_begin; const char* s = text_begin;
if (!word_wrap_enabled && y + line_height < clip_rect.y)
while (s < text_end && *s != '\n') // Fast-forward to next line
s++;
while (s < text_end) while (s < text_end)
{ {
if (word_wrap_enabled) if (word_wrap_enabled)
@ -10085,6 +10089,13 @@ void ImFont::RenderText(float size, ImVec2 pos, ImU32 col, const ImVec4& clip_re
{ {
x = pos.x; x = pos.x;
y += line_height; y += line_height;
if (y > clip_rect.w)
break;
if (!word_wrap_enabled && y + line_height < clip_rect.y)
while (s < text_end && *s != '\n') // Fast-forward to next line
s++;
continue; continue;
} }
if (c == '\r') if (c == '\r')
@ -10095,78 +10106,70 @@ void ImFont::RenderText(float size, ImVec2 pos, ImU32 col, const ImVec4& clip_re
if (const Glyph* glyph = FindGlyph((unsigned short)c)) if (const Glyph* glyph = FindGlyph((unsigned short)c))
{ {
char_width = glyph->XAdvance * scale; char_width = glyph->XAdvance * scale;
// Clipping on Y is more likely
if (c != ' ' && c != '\t') if (c != ' ' && c != '\t')
{ {
// Clipping on Y is more likely // We don't do a second finer clipping test on the Y axis (todo: do some measurement see if it is worth it, probably not)
float y1 = (float)(y + glyph->YOffset * scale); float y1 = (float)(y + glyph->YOffset * scale);
if (y1 > clip_rect.w)
break;
float y2 = (float)(y1 + glyph->Height * scale); float y2 = (float)(y1 + glyph->Height * scale);
if (y2 < clip_rect.y)
float x1 = (float)(x + glyph->XOffset * scale);
float x2 = (float)(x1 + glyph->Width * scale);
if (x1 <= clip_rect.z && x2 >= clip_rect.x)
{ {
// Fast-forward until next line // Render a character
char_width = 0.0f; float u1 = glyph->U0;
while (s < text_end && *s != '\n') s++; float v1 = glyph->V0;
} float u2 = glyph->U1;
else float v2 = glyph->V1;
{
float x1 = (float)(x + glyph->XOffset * scale); // CPU side clipping used to fit text in their frame when the frame is too small. Only does clipping for axis aligned quads
float x2 = (float)(x1 + glyph->Width * scale); if (cpu_fine_clip)
if (x1 <= clip_rect.z && x2 >= clip_rect.x)
{ {
// Render a character if (x1 < clip_rect.x)
float u1 = glyph->U0;
float v1 = glyph->V0;
float u2 = glyph->U1;
float v2 = glyph->V1;
// CPU side clipping used to fit text in their frame when the frame is too small. Only does clipping for axis aligned quads
if (cpu_fine_clip)
{ {
if (x1 < clip_rect.x) u1 = u1 + (1.0f - (x2 - clip_rect.x) / (x2 - x1)) * (u2 - u1);
{ x1 = clip_rect.x;
u1 = u1 + (1.0f - (x2 - clip_rect.x) / (x2 - x1)) * (u2 - u1); }
x1 = clip_rect.x; if (y1 < clip_rect.y)
} {
if (y1 < clip_rect.y) v1 = v1 + (1.0f - (y2 - clip_rect.y) / (y2 - y1)) * (v2 - v1);
{ y1 = clip_rect.y;
v1 = v1 + (1.0f - (y2 - clip_rect.y) / (y2 - y1)) * (v2 - v1); }
y1 = clip_rect.y; if (x2 > clip_rect.z)
} {
if (x2 > clip_rect.z) u2 = u1 + ((clip_rect.z - x1) / (x2 - x1)) * (u2 - u1);
{ x2 = clip_rect.z;
u2 = u1 + ((clip_rect.z - x1) / (x2 - x1)) * (u2 - u1); }
x2 = clip_rect.z; if (y2 > clip_rect.w)
} {
if (y2 > clip_rect.w) v2 = v1 + ((clip_rect.w - y1) / (y2 - y1)) * (v2 - v1);
{ y2 = clip_rect.w;
v2 = v1 + ((clip_rect.w - y1) / (y2 - y1)) * (v2 - v1);
y2 = clip_rect.w;
}
} }
// NB: we are not calling PrimRectUV() here because non-inlined causes too much overhead in a debug build.
out_vertices[0].pos = ImVec2(x1, y1);
out_vertices[0].uv = ImVec2(u1, v1);
out_vertices[0].col = col;
out_vertices[1].pos = ImVec2(x2, y1);
out_vertices[1].uv = ImVec2(u2, v1);
out_vertices[1].col = col;
out_vertices[2].pos = ImVec2(x2, y2);
out_vertices[2].uv = ImVec2(u2, v2);
out_vertices[2].col = col;
out_vertices[3] = out_vertices[0];
out_vertices[4] = out_vertices[2];
out_vertices[5].pos = ImVec2(x1, y2);
out_vertices[5].uv = ImVec2(u1, v2);
out_vertices[5].col = col;
out_vertices += 6;
} }
// NB: we are not calling PrimRectUV() here because non-inlined causes too much overhead in a debug build.
out_vertices[0].pos = ImVec2(x1, y1);
out_vertices[0].uv = ImVec2(u1, v1);
out_vertices[0].col = col;
out_vertices[1].pos = ImVec2(x2, y1);
out_vertices[1].uv = ImVec2(u2, v1);
out_vertices[1].col = col;
out_vertices[2].pos = ImVec2(x2, y2);
out_vertices[2].uv = ImVec2(u2, v2);
out_vertices[2].col = col;
out_vertices[3] = out_vertices[0];
out_vertices[4] = out_vertices[2];
out_vertices[5].pos = ImVec2(x1, y2);
out_vertices[5].uv = ImVec2(u1, v2);
out_vertices[5].col = col;
out_vertices += 6;
} }
} }
} }