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/*
* Copyright 2012 Google, Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Google Author(s): Behdad Esfahbod
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "demo-buffer.h"
struct demo_buffer_t {
unsigned int refcount;
glyphy_point_t cursor;
std::vector<glyph_vertex_t> *vertices;
glyphy_extents_t ink_extents;
glyphy_extents_t logical_extents;
bool dirty;
GLuint buf_name;
};
demo_buffer_t *
demo_buffer_create (void)
{
demo_buffer_t *buffer = static_cast<demo_buffer_t *>(calloc (1, sizeof (demo_buffer_t)));
buffer->refcount = 1;
buffer->vertices = new std::vector<glyph_vertex_t>;
glGenBuffers (1, &buffer->buf_name);
demo_buffer_clear (buffer);
return buffer;
}
demo_buffer_t *
demo_buffer_reference (demo_buffer_t *buffer)
{
if (buffer) buffer->refcount++;
return buffer;
}
void
demo_buffer_destroy (demo_buffer_t *buffer)
{
if (!buffer || --buffer->refcount)
return;
glDeleteBuffers (1, &buffer->buf_name);
delete buffer->vertices;
free (buffer);
}
void
demo_buffer_clear (demo_buffer_t *buffer)
{
buffer->vertices->clear ();
glyphy_extents_clear (&buffer->ink_extents);
glyphy_extents_clear (&buffer->logical_extents);
buffer->dirty = true;
}
void
demo_buffer_extents (demo_buffer_t *buffer,
glyphy_extents_t *ink_extents,
glyphy_extents_t *logical_extents)
{
if (ink_extents)
*ink_extents = buffer->ink_extents;
if (logical_extents)
*logical_extents = buffer->logical_extents;
}
void
demo_buffer_move_to (demo_buffer_t *buffer,
const glyphy_point_t *p)
{
buffer->cursor = *p;
}
void
demo_buffer_current_point (demo_buffer_t *buffer,
glyphy_point_t *p)
{
*p = buffer->cursor;
}
void
demo_buffer_add_text (demo_buffer_t *buffer,
const char *utf8,
demo_font_t *font,
double font_size)
{
#ifndef _WIN32
FT_Face face = demo_font_get_face (font);
#else
HDC hdc = demo_font_get_face (font);
#endif
glyphy_point_t top_left = buffer->cursor;
buffer->cursor.y += font_size /* * font->ascent */;
unsigned int unicode;
for (const unsigned char *p = reinterpret_cast<const unsigned char *>(utf8); *p; p++) {
if (*p < 128) {
unicode = *p;
} else {
unsigned int j;
if (*p < 0xE0) {
unicode = *p & ~0xE0;
j = 1;
} else if (*p < 0xF0) {
unicode = *p & ~0xF0;
j = 2;
} else {
unicode = *p & ~0xF8;
j = 3;
continue;
}
p++;
for (; j && *p; j--, p++)
unicode = (unicode << 6) | (*p & ~0xC0);
p--;
}
if (unicode == '\n') {
buffer->cursor.y += font_size;
buffer->cursor.x = top_left.x;
continue;
}
#ifndef _WIN32
unsigned int glyph_index = FT_Get_Char_Index (face, unicode);
#else
wchar_t wc = unicode; /* FIXME: What about non-BMP chars? */
WORD glyph_index;
if (GetGlyphIndicesW (hdc, &wc, 1, &glyph_index, GGI_MARK_NONEXISTING_GLYPHS) == GDI_ERROR)
die ("GetGlyphIndicesW failed");
#endif
glyph_info_t gi;
demo_font_lookup_glyph (font, glyph_index, &gi);
/* Update ink extents */
glyphy_extents_t ink_extents;
demo_shader_add_glyph_vertices (buffer->cursor, font_size, &gi, buffer->vertices, &ink_extents);
glyphy_extents_extend (&buffer->ink_extents, &ink_extents);
/* Update logical extents */
glyphy_point_t corner;
corner.x = buffer->cursor.x;
corner.y = buffer->cursor.y - font_size;
glyphy_extents_add (&buffer->logical_extents, &corner);
corner.x = buffer->cursor.x + font_size * gi.advance;
corner.y = buffer->cursor.y;
glyphy_extents_add (&buffer->logical_extents, &corner);
buffer->cursor.x += font_size * gi.advance;
}
buffer->dirty = true;
}
void
demo_buffer_draw (demo_buffer_t *buffer)
{
GLint program;
glGetIntegerv (GL_CURRENT_PROGRAM, &program);
GLuint a_glyph_vertex_loc = glGetAttribLocation (program, "a_glyph_vertex");
glBindBuffer (GL_ARRAY_BUFFER, buffer->buf_name);
if (buffer->dirty) {
glBufferData (GL_ARRAY_BUFFER, sizeof (glyph_vertex_t) * buffer->vertices->size (), &(*buffer->vertices)[0], GL_STATIC_DRAW);
buffer->dirty = false;
}
glEnableVertexAttribArray (a_glyph_vertex_loc);
glVertexAttribPointer (a_glyph_vertex_loc, 4, GL_FLOAT, GL_FALSE, sizeof (glyph_vertex_t), nullptr);
glDrawArrays (GL_TRIANGLES, 0, buffer->vertices->size ());
glDisableVertexAttribArray (a_glyph_vertex_loc);
}
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