weston/libweston/renderer-gl/vertex.glsl
Loïc Molinari bcd04e0fad gl-renderer: Derive texcoords from position in the vertex shader
Let the graphics hardware handle the transformation from surface
position to texture coordinates. Paint nodes now have a single vertex
position attribute from which texture coordinates are derived. A new
vertex shader variant handles the transformation.

Signed-off-by: Loïc Molinari <loic.molinari@gmail.com>
2023-06-12 11:15:51 +00:00

60 lines
2.0 KiB
GLSL

/*
* Copyright 2012 Intel Corporation
* Copyright 2015,2019 Collabora, Ltd.
* Copyright 2016 NVIDIA Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/* enum gl_shader_texcoord_input */
#define SHADER_TEXCOORD_INPUT_ATTRIB 0
#define SHADER_TEXCOORD_INPUT_SURFACE 1
/* Always use high-precision for vertex calculations */
precision highp float;
#ifdef GL_FRAGMENT_PRECISION_HIGH
#define FRAG_PRECISION highp
#else
#define FRAG_PRECISION mediump
#endif
uniform mat4 proj;
uniform mat4 surface_to_buffer;
attribute vec2 position;
attribute vec2 texcoord;
/* Match the varying precision to the fragment shader */
varying FRAG_PRECISION vec2 v_texcoord;
void main()
{
gl_Position = proj * vec4(position, 0.0, 1.0);
#if DEF_TEXCOORD_INPUT == SHADER_TEXCOORD_INPUT_ATTRIB
v_texcoord = texcoord;
#elif DEF_TEXCOORD_INPUT == SHADER_TEXCOORD_INPUT_SURFACE
v_texcoord = vec2(surface_to_buffer * vec4(position, 0.0, 1.0));
#endif
}