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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-shader.h"
#include "demo-atlas-glsl.h"
#include "demo-vshader-glsl.h"
#include "demo-fshader-glsl.h"
static unsigned int
glyph_encode (unsigned int atlas_x , /* 7 bits */
unsigned int atlas_y, /* 7 bits */
unsigned int corner_x, /* 1 bit */
unsigned int corner_y, /* 1 bit */
unsigned int nominal_w, /* 6 bits */
unsigned int nominal_h /* 6 bits */)
{
assert (0 == (atlas_x & ~0x7F));
assert (0 == (atlas_y & ~0x7F));
assert (0 == (corner_x & ~1));
assert (0 == (corner_y & ~1));
assert (0 == (nominal_w & ~0x3F));
assert (0 == (nominal_h & ~0x3F));
unsigned int x = (((atlas_x << 6) | nominal_w) << 1) | corner_x;
unsigned int y = (((atlas_y << 6) | nominal_h) << 1) | corner_y;
return (x << 16) | y;
}
static void
glyph_vertex_encode (double x, double y,
unsigned int corner_x, unsigned int corner_y,
const glyph_info_t *gi,
glyph_vertex_t *v)
{
unsigned int encoded = glyph_encode (gi->atlas_x, gi->atlas_y,
corner_x, corner_y,
gi->nominal_w, gi->nominal_h);
v->x = x;
v->y = y;
v->g16hi = encoded >> 16;
v->g16lo = encoded & 0xFFFF;
}
void
demo_shader_add_glyph_vertices (const glyphy_point_t &p,
double font_size,
glyph_info_t *gi,
std::vector<glyph_vertex_t> *vertices,
glyphy_extents_t *extents)
{
if (gi->is_empty)
return;
glyph_vertex_t v[4];
#define ENCODE_CORNER(_cx, _cy) \
do { \
double _vx = p.x + font_size * ((1-_cx) * gi->extents.min_x + _cx * gi->extents.max_x); \
double _vy = p.y - font_size * ((1-_cy) * gi->extents.min_y + _cy * gi->extents.max_y); \
glyph_vertex_encode (_vx, _vy, _cx, _cy, gi, &v[_cx * 2 + _cy]); \
} while (false)
ENCODE_CORNER (0, 0);
ENCODE_CORNER (0, 1);
ENCODE_CORNER (1, 0);
ENCODE_CORNER (1, 1);
#undef ENCODE_CORNER
vertices->push_back (v[0]);
vertices->push_back (v[1]);
vertices->push_back (v[2]);
vertices->push_back (v[1]);
vertices->push_back (v[2]);
vertices->push_back (v[3]);
if (extents) {
glyphy_extents_clear (extents);
for (unsigned int i = 0; i < 4; i++) {
glyphy_point_t p2 = {v[i].x, v[i].y};
glyphy_extents_add (extents, &p2);
}
}
}
static GLuint
compile_shader (GLenum type,
GLsizei count,
const GLchar** sources)
{
TRACE();
GLuint shader;
GLint compiled;
if (!(shader = glCreateShader (type)))
return shader;
glShaderSource (shader, count, sources, nullptr);
glCompileShader (shader);
glGetShaderiv (shader, GL_COMPILE_STATUS, &compiled);
if (!compiled) {
GLint info_len = 0;
LOGW ("%s shader failed to compile\n",
type == GL_VERTEX_SHADER ? "Vertex" : "Fragment");
glGetShaderiv (shader, GL_INFO_LOG_LENGTH, &info_len);
if (info_len > 0) {
char *info_log = static_cast<char*>(malloc (info_len));
glGetShaderInfoLog (shader, info_len, nullptr, info_log);
LOGW ("%s\n", info_log);
free (info_log);
}
abort ();
}
return shader;
}
static GLuint
link_program (GLuint vshader,
GLuint fshader)
{
TRACE();
GLuint program;
GLint linked;
program = glCreateProgram ();
glAttachShader (program, vshader);
glAttachShader (program, fshader);
glLinkProgram (program);
glDeleteShader (vshader);
glDeleteShader (fshader);
glGetProgramiv (program, GL_LINK_STATUS, &linked);
if (!linked) {
GLint info_len = 0;
LOGW ("Program failed to link\n");
glGetProgramiv (program, GL_INFO_LOG_LENGTH, &info_len);
if (info_len > 0) {
char *info_log = static_cast<char*>(malloc (info_len));
glGetProgramInfoLog (program, info_len, nullptr, info_log);
LOGW ("%s\n", info_log);
free (info_log);
}
abort ();
}
return program;
}
#ifdef GL_ES_VERSION_2_0
# define GLSL_HEADER_STRING \
"#extension GL_OES_standard_derivatives : enable\n" \
"precision highp float;\n" \
"precision highp int;\n"
#else
# define GLSL_HEADER_STRING \
"#version 110\n"
#endif
GLuint
demo_shader_create_program (void)
{
TRACE();
GLuint vshader, fshader, program;
const GLchar *vshader_sources[] = {GLSL_HEADER_STRING,
demo_vshader_glsl};
vshader = compile_shader (GL_VERTEX_SHADER, ARRAY_LEN (vshader_sources), vshader_sources);
const GLchar *fshader_sources[] = {GLSL_HEADER_STRING,
demo_atlas_glsl,
glyphy_common_shader_source (),
"#define GLYPHY_SDF_PSEUDO_DISTANCE 1\n",
glyphy_sdf_shader_source (),
demo_fshader_glsl};
fshader = compile_shader (GL_FRAGMENT_SHADER, ARRAY_LEN (fshader_sources), fshader_sources);
program = link_program (vshader, fshader);
return program;
}
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