Package org.lwjgl.opengl

Class EXTRasterMultisample

java.lang.Object

org.lwjgl.opengl.EXTRasterMultisample

public class EXTRasterMultisample
extends java.lang.Object

Native bindings to the EXT_raster_multisample extension.

This extension allows rendering to a non-multisample color buffer while rasterizing with more than one sample. The result of rasterization (coverage) is available in the gl_SampleMaskIn[] fragment shader input, multisample rasterization is enabled for all primitives, and several per- fragment operations operate at the raster sample rate.

When using the functionality provided by this extension, depth, stencil, and depth bounds tests must be disabled, and a multisample draw framebuffer must not be used.

A fragment's "coverage", or "effective raster samples" is considered to have "N bits" (as opposed to "one bit" corresponding to the single color sample) through the fragment shader, in the sample mask output, through the multisample fragment operations and occlusion query, until the coverage is finally "reduced" to a single bit in a new "Coverage Reduction" stage that occurs before blending.

Field Summary

Fields

Modifier and Type	Field and Description
static int	GL_EFFECTIVE_RASTER_SAMPLES_EXT GL_MAX_RASTER_SAMPLES_EXT GL_MULTISAMPLE_RASTERIZATION_ALLOWED_EXT GL_RASTER_FIXED_SAMPLE_LOCATIONS_EXT Accepted by the pname parameter of GetBooleanv, GetDoublev, GetIntegerv, and GetFloatv.
static int	GL_RASTER_MULTISAMPLE_EXT Accepted by the cap parameter of Enable, Disable, IsEnabled.
static int	GL_RASTER_SAMPLES_EXT Accepted by the pname parameter of GetBooleanv, GetDoublev, GetIntegerv, and GetFloatv.

Method Summary

Modifier and Type	Method and Description
static void	glRasterSamplesEXT(int samples, boolean fixedsamplelocations) Selects the number of samples to be used for rasterization.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

GL_RASTER_MULTISAMPLE_EXT

Accepted by the cap parameter of Enable, Disable, IsEnabled.

GL_RASTER_SAMPLES_EXT, GL_MAX_RASTER_SAMPLES_EXT, GL_RASTER_FIXED_SAMPLE_LOCATIONS_EXT, GL_MULTISAMPLE_RASTERIZATION_ALLOWED_EXT, GL_EFFECTIVE_RASTER_SAMPLES_EXT

Accepted by the pname parameter of GetBooleanv, GetDoublev, GetIntegerv, and GetFloatv.

Method Detail

glRasterSamplesEXT

public static void glRasterSamplesEXT(int samples,
                                      boolean fixedsamplelocations)

Selects the number of samples to be used for rasterization. samples represents a request for a desired minimum number of samples. Since different implementations may support different sample counts, the actual sample pattern used is implementation-dependent. However, the resulting value for RASTER_SAMPLES_EXT is guaranteed to be greater than or equal to samples and no more than the next larger sample count supported by the implementation. If fixedsamplelocations is TRUE, identical sample locations will be used for all pixels. The sample locations chosen are a function of only the parameters to RasterSamplesEXT and not of any other state.

If RASTER_MULTISAMPLE_EXT is enabled, then the sample pattern chosen by RasterSamplesEXT will be used instead of sampling at the center of the pixel. The sample locations can be queried with GetMultisamplefv with a pname of SAMPLE_POSITION, similar to normal multisample sample locations.

The value MULTISAMPLE_RASTERIZATION_ALLOWED_EXT is TRUE if SAMPLE_BUFFERS is one or if RASTER_MULTISAMPLE_EXT is enabled. The value EFFECTIVE_RASTER_SAMPLES_EXT is equal to RASTER_SAMPLES_EXT if RASTER_MULTISAMPLE_EXT is enabled, otherwise is equal to SAMPLES.

Explicit multisample rasterization can not be used in conjunction with depth, stencil, or depth bounds tests, multisample framebuffers, or if RASTER_SAMPLES_EXT is zero. If RASTER_MULTISAMPLE_EXT is enabled, the error INVALID_OPERATION will be generated by Draw commands if

• the value of RASTER_SAMPLES_EXT is zero
• the depth, stencil, or depth bounds test is enabled
• a multisample draw framebuffer is bound (SAMPLE_BUFFERS is one)

Errors

An INVALID_VALUE error is generated if samples is greater than the value of MAX_RASTER_SAMPLES_EXT (the implementation-dependent maximum number of samples).

Parameters:

samples - the number of samples to be used for rasterization

fixedsamplelocations - if TRUE, identical sample locations will be used for all pixels