Beside the defines you can pass as an argument using -D[define] you can relay on the following native defines automatically generated for you. Remember you can always use the defines commands to have a sense of all the active define flags, their values on each shader/subshader

• GLSLVIEWER <GLSLVIEWER_VERSION_WOUT_DOTS>: you can use it to tell your shader it's being render in GlslViewer.

• PLATFORM_OSX: added only on MacOS/OSX platforms.

• PLATFORM_RPI: added only on RaspberryPi devices.

• PLATFORM_LINUX: added only in i86 and 64bit Linux platforms.

• PLATFORM_WEBGL: added only on WASM or WebGL platforms.

The following defines fork and reuse the same shader program in different buffers

• BUFFER_[NUMBER]: added extra buffer passes through branching subshader. Each time you add a uniform sampler2D u_buffer[NUMBER];, glslViewer will run another version of the same shader code but with the #define BUFFER_[NUMBER] on top and save the content into u_buffer[NUMBER] texture buffer. This way you can code different passes with a single source file. Please take a look to this examples to see how this works.

• DOUBLE_BUFFER_[NUMBER]: added extra double buffer (for PingPong passes) through branching subshader. Each time you add a uniform sampler2D u_doubleBuffer[NUMBER];, glslViewer will run another version of the same shader code but with the #define DOUBLE_BUFFER_[NUMBER] on top and save the content into u_buffer[NUMBER] texture buffer. This way you can code different Ping-Pong passes with a single source file. Please take a look to this examples to see how this works.

• PYRAMID_[NUMBER]: perform Convolution Pyramids to the content of a buffer where the result will be stored as uniform sampler2D u_pyramid[NUMBER]. Please take a look to this examples to see how this works. For advance use is possible to overwrite the up/down scaling shaders using #ifdef PYRAMID_ALGORITHM and the uniforms:

uniform sampler2D   u_pyramidTex0;
uniform sampler2D   u_pyramidTex1;
uniform bool        u_pyramidUpscaling;

The following defines fork and reuse the same shader program in different passes

• BACKGROUND: added a background subshader when rendering a 3D geometry.

• FLOOR: add a floor geometry and fork the behavior of the shader to render the floor using it

• POSTPROCESSING: added a post-processing pass where the main scene have been render to uniform sampler2D u_scene; and uniform sampler2D u_sceneDepth;.

• MODEL_NAME_<NAME>: only OBJ file import a name. Default is MODEL_NAME_MESH

• MODEL_VERTEX_COLOR: if the model have a vertex color attribute will be follow by the name of the attribute (Default: a_color)

• MODEL_VERTEX_NORMAL: if the model have a vertex normal attribute will be follow by the name of the attribute (Default: a_normal`)

• MODEL_VERTEX_TEXCOORD: if the model have a vertex normal attribute will be follow by the name of the attribute (Default: a_texcoord)

• MODEL_VERTEX_TANGENT: if the model have a vertex normal attribute will be follow by the name of the attribute (Default: a_tangent)

• MATERIAL_NAME_[NAME]: only OBJ file import a name. Default is MATERIAL_NAME_DEFAULT

• MATERIAL_ILLUM: integer between 0 to 10. Specs from here

    0 Color on and Ambient off
    1 Color on and Ambient on
    2 Highlight on
    3 Reflection on and Ray trace on
    4 Transparency: Glass on

    Reflection: Ray trace on
    5 Reflection: Fresnel on and Ray trace on
    6 Transparency: Refraction on

    Reflection: Fresnel off and Ray trace on
    7 Transparency: Refraction on

    Reflection: Fresnel on and Ray trace on
    8 Reflection on and Ray trace off
    9 Transparency: Glass on

    Reflection: Ray trace off
    10 Casts shadows onto invisible surfaces

• MATERIAL_AMBIENT: the color as vec3

• MATERIAL_AMBIENTMAP: the name of a sampler2D

• MATERIAL_BASECOLOR: a color as vec3

• MATERIAL_BASECOLORMAP: the name of a sampler2D

• MATERIAL_SPECULAR: a color as vec3

• MATERIAL_SPECULARMAP: the name of a sampler2D

• MATERIAL_ROUGHNESS: a normalize float value

• MATERIAL_ROUGHNESSMAP: the name of a sampler2D

• MATERIAL_METALLIC: a normalize float value

• MATERIAL_METALLICMAP: the name of a sampler2D

• MATERIAL_SHININESS: a scallar factor for speculars

• MATERIAL_SHEEN: a normalize float value

• MATERIAL_SHEENMAP: the name of a sampler2D

• MATERIAL_SPECULAR_HIGHLIGHTMAP: the name of a sampler2D

• MATERIAL_REFLECTIONMAP: the name of a sampler2D

• MATERIAL_CLEARCOAT_THICKNESS: a normalize float value

• MATERIAL_CLEARCOAT_ROUGHNESS: a normalize float value

• MATERIAL_ANISOTROPY: a normalize float value

• MATERIAL_ANISOTROPY_ROTATION: float value

• MATERIAL_EMISSIVE: a color as vec3

• MATERIAL_EMISSIVEMAP: the name of a sampler2D

• MATERIAL_NORMALMAP: the name of a sampler2D

• MATERIAL_BUMPMAP: the name of a sampler2D

• MATERIAL_DISPLACEMENTMAP: the name of a sampler2D

• MATERIAL_ALPHAMAP: the name of a sampler2D

• MATERIAL_TRANSMITTANCE: a color as vec3

• MATERIAL_DISSOLVE: a normalize float value

• MATERIAL_IOR: a normalize float value