RetroArch/gfx/drivers_shader/glslang_util.cpp
2016-03-24 04:09:25 +01:00

155 lines
3.9 KiB
C++

/* RetroArch - A frontend for libretro.
* Copyright (C) 2010-2016 - Hans-Kristian Arntzen
*
* RetroArch is free software: you can redistribute it and/or modify it under the terms
* of the GNU General Public License as published by the Free Software Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with RetroArch.
* If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <string>
#include <sstream>
#include <streams/file_stream.h>
#include <lists/string_list.h>
#include "glslang_util.hpp"
#include "glslang.hpp"
#include "../../general.h"
#include "../../libretro-common/include/file/file_path.h"
using namespace std;
static bool read_shader_file(const char *path, vector<string> *output)
{
char *buf = nullptr;
ssize_t len = 0;
struct string_list *list = NULL;
char include_path[PATH_MAX];
if (filestream_read_file(path, (void**)&buf, &len) < 0)
{
RARCH_ERR("Failed to open shader file: \"%s\".\n", path);
return false;
}
list = string_split(buf, "\n");
if (!list)
{
free(buf);
return false;
}
if (list->size == 0)
{
free(buf);
string_list_free(list);
return false;
}
for (size_t i = 0; i < list->size; i++)
{
const char *line = list->elems[i].data;
if (strstr(line, "#include ") == line)
{
char *c = (char*)strchr(line, '"');
if (!c)
{
RARCH_ERR("Invalid include statement \"%s\".\n", line);
return false;
}
c++;
char *closing = (char*)strchr(c, '"');
if (!closing)
{
RARCH_ERR("Invalid include statement \"%s\".\n", line);
return false;
}
*closing = '\0';
fill_pathname_resolve_relative(include_path, path, c, sizeof(include_path));
if (!read_shader_file(include_path, output))
return false;
}
else
output->push_back(line);
}
string_list_free(list);
return true;
}
static string build_stage_source(const vector<string> &lines, const char *stage)
{
ostringstream str;
bool active = true;
// Version header.
str << lines.front();
str << '\n';
for (auto itr = begin(lines) + 1; itr != end(lines); ++itr)
{
if (itr->find("#pragma stage ") != string::npos)
{
auto expected = string("#pragma stage ") + stage;
active = itr->find(expected) != string::npos;
// Improve debuggability.
if (active)
{
str << "#line ";
str << (itr - begin(lines)) + 2;
str << '\n';
}
}
else if (active)
str << *itr;
str << '\n';
}
return str.str();
}
bool glslang_compile_shader(const char *shader_path, glslang_output *output)
{
vector<string> lines;
RARCH_LOG("Compiling shader \"%s\".\n", shader_path);
if (!read_shader_file(shader_path, &lines))
return false;
auto &header = lines.front();
if (header.find_first_of("#version ") == string::npos)
{
RARCH_ERR("First line of the shader must contain a valid #version string.\n");
return false;
}
if (!glslang::compile_spirv(build_stage_source(lines, "vertex"),
glslang::StageVertex, &output->vertex))
{
RARCH_ERR("Failed to compile vertex shader stage.\n");
return false;
}
if (!glslang::compile_spirv(build_stage_source(lines, "fragment"),
glslang::StageFragment, &output->fragment))
{
RARCH_ERR("Failed to compile fragment shader stage.\n");
return false;
}
return true;
}