Editing Shaders (Shaders)

Shaders

The active shaders should be located in the contents/files/shaders folder. There are four shaders that can be used. The outputs of the base shaders are sent to the final shaders in the form of textures.

base.fsh

This shader is the basic fragment shader.

=== /*

---

Note: - DOF doesn't seem work well with the other

  shaders. The blur overrides all other shaders
 

- Bloom seems to reduce the effect of

  the SSAO shader ===

Credits: - azraeil ( DOF Shader ) - Yourself ( CEL Shading ) - Dilla/snowcrash ( Bloom Shader ) - Leadwerks ( SSAO Shader ) - .jhn ( pseudo-AA Shader )

---

• /

// To disable one of these features put a "//" in front of the "#define"

//#define DOF_ENABLED

1. define BLOOM_ENABLED

//#define AA_ENABLED

1. define SSAO_ENABLED
2. define CEL_SHADING

=== #ifdef CEL_SHADING const float CEL_EDGE_THRESHOLD = 0.15; const float CEL_EDGE_THICKNESS = 0.65;

1. endif
2. ifdef BLOOM_ENABLED

const float BLOOM_STRENGTH = 0.25;

1. endif
2. ifdef DOF_ENABLED

const float HYPERFOCAL = 4.0;

1. endif ===

/*

---

The standard user should not mess with anything below

---

• /

=== uniform sampler2D sampler0; uniform sampler2D sampler1; uniform sampler2D sampler2; uniform sampler2D bgl_RenderedTexture; === uniform float displayWidth; uniform float displayHeight; uniform float aspectRatio; uniform float near; uniform float far;

Pre-processor Defines

Base Defines

_ENABLE_GL_TEXTURE_2D

Defined when the shader should use a texture.

A basic fragment shader should calculate gl_FragColor something like this:

#ifdef _ENABLE_GL_TEXTURE_2D
    gl_FragColor = texture2D(sampler0, gl_TexCoord[0].st) * vertColor;
#else
    gl_FragColor = vertColor;
#endif

_ENABLE_BUMP_MAPPING

Defined when a normal map and specular map have been bound.

Structures

lightSource

struct lightSource {
    int itemId;
    float magnitude;
    vec4 specular;
};

Attributes

vec4 mc_Entity

mc_Entity.x

The x component of mc_Entity is the entity id. Currently this is only set for blocks. In future updates it will be set for items and mobs. It will have a value of -1.0 for unknown entities.

mc_Entity.y

The y component of mc_Entity contains information regarding lighting. It is currently calculated as lightValue * 16 + brightness. In future updates other additions may be made to this (such as the sides exposed to the sky).

In the shaders, lightValue can be obtained by mod(floor(mc_Entity.y / 16.0), 16.0). brightness can be obtained by mod(mc_Entity.y, 16.0).

mc_Entity.z

Reserved

mc_Entity.w

Reserved

Uniforms

There are several uniforms available to the shaders.

Global Uniforms

float displayWidth

The width of the display.

float displayHeight

The height of the display.

float aspectRatio

The aspect ratio of the display (displayWidth / displayHeight).

float near

The near viewing plane.

float far

The far viewing plane.

int fogMode

The current fog mode. The possible values are as follows:

const int GL_LINEAR = 9729;
const int GL_EXP = 2048;

float sunVector

The position of the sun in eye coordinates.

float moonVector

The position of the moon in eye coordinates.

int worldTime

The world time of day (ranges from 0 to 23999).

lightSource heldLight

The properties of the item currently being held.

Base Uniforms

sampler2D sampler0

The texture of the current element.

sampler2D sampler1

The normals and height-map for the current texture (loaded from XXXXX_nh.png). At the moment this is only accurate when renderType is equal to RENDER_TYPE_TERRAIN.

int renderType - Deprecated, don't use.

The type of element being rendered. The possible values are as follows:

const int RENDER_TYPE_UNKNOWN = 0;
const int RENDER_TYPE_TERRAIN = 1;

Final Uniforms

sampler2D sampler0

The rendered scene.

sampler2D sampler1

The depth of the rendered scene, excluding the player's arm.

sampler2D sampler2

The depth of the player's arm.

Tips

Anti-Aliasing

To avoid anti-aliasing on polygon edges, texture coordinates should be declared as centroid in the base vertex and fragment shaders.