跨GLSL與GLSLES shader code

主要目的是為了能在PC Windows上可以直接測試glsles（雖然有很多GLSL的內建變數無法使用，可能會造成GLSL可以跑，GLSLES卻無法執行的問題…），這樣可以加快開發GLSLES Shader的速度。

範例：

Vertex Shader Code：

//-----------------------------------------------------------------------------
//                         GLOBAL Defination
//-----------------------------------------------------------------------------
#ifdef USE_GL
  #version 120
#else
  #version 100
precision mediump int;
precision highp float;
#endif
//-----------------------------------------------------------------------------
//                         GLOBAL PARAMETERS
//-----------------------------------------------------------------------------
uniform mat4 worldviewproj_matrix;
//-----------------------------------------------------------------------------
//                         Vertex Inputs
//-----------------------------------------------------------------------------
attribute vec4 position;
attribute vec2 uv0;
//-----------------------------------------------------------------------------
//                         Vertex Outputs
//-----------------------------------------------------------------------------
//Outputs
//the name need to be the same pixel input name.
varying vec2 oUv;
//-----------------------------------------------------------------------------
// Function Name: main
// Function Desc: Vertex Program Entry point
//-----------------------------------------------------------------------------
void main()
{
gl_Position = worldviewproj_matrix*position;
oUv = uv0;
}
#####################################################################

Fragment Shader Code：

//-----------------------------------------------------------------------------
//                         GLOBAL Defination
//-----------------------------------------------------------------------------
#ifdef USE_GL
  #version 120
#else
  #version 100
precision mediump int;
precision highp float;
precision highp sampler2D;
#endif
//-----------------------------------------------------------------------------
//                         GLOBAL PARAMETERS
//-----------------------------------------------------------------------------
uniform sampler2D DiffuseMap;
//-----------------------------------------------------------------------------
//                         Pixel Inputs
//-----------------------------------------------------------------------------
varying vec2 oUv;
//-----------------------------------------------------------------------------
// Function Name: main
// Function Desc: Pixel Program Entry point
//-----------------------------------------------------------------------------
void main()
{
gl_FragColor = texture2D(DiffuseMap, oUv);
}
#####################################################################

Material Script：

vertex_program Base_VP_GLSL glsl
{
source Programs/Base_VP.glsles
 preprocessor_defines USE_GL=1
default_params
{
param_named_auto worldviewproj_matrix worldviewproj_matrix
}
}

vertex_program Base_VP_GLSLES glsles
{
source Programs/Base_VP.glsles
profiles glsles
default_params
{
param_named_auto worldviewproj_matrix worldviewproj_matrix
}
}

vertex_program Base_VP unified
{
delegate Base_VP_GLSLES
delegate Base_VP_GLSL
}

fragment_program Base_FP_GLSL glsl
{
source Programs/Base_FP.glsles
 preprocessor_defines USE_GL=1
default_params
{
param_named DiffuseMap int 0
}
}

fragment_program Base_FP_GLSLES glsles
{
source Programs/Base_FP.glsles
profiles glsles
default_params
{
param_named DiffuseMap int 0
}
}

fragment_program Base_FP unified
{
delegate Base_FP_GLSLES
delegate Base_FP_GLSL
}


material Template_Basic
{
technique
{
pass Base
{
// Vertex program reference
vertex_program_ref Base_VP
{
}
// Fragment program reference
fragment_program_ref Base_FP
{
}
texture_unit BaseMap
{
}
}
}
}



此範例OpenGL Render System來執行可以畫出跟GLSLES2.0一樣的結果。

備註：關於varying這個部份，GLSL ES2.0只要順序對，名稱不一樣也不會出錯，但GLSL則Vertex和Fragment Shader一定要一樣。

夢想還在持中…