/*

 * This file is part of OpenTTD.

 * OpenTTD 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 Foundation, version 2.

 * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.

 */

/** @file opengl_shader.h OpenGL shader programs. */

/** Vertex shader that positions a sprite on screen.. */

static const char *_vertex_shader_sprite[] = {

	"#version 110\n",

	"uniform vec4 sprite;",

	"uniform vec2 screen;",

	"attribute vec2 position, colour_uv;",

	"varying vec2 colour_tex_uv;",

	"void main() {",

	"  vec2 size = sprite.zw / screen.xy;",

	"  vec2 offset = ((2.0 * sprite.xy + sprite.zw) / screen.xy - 1.0) * vec2(1.0, -1.0);",

	"  colour_tex_uv = colour_uv;",

	"  gl_Position = vec4(position * size + offset, 0.0, 1.0);",

	"}",

};