Version: alpha
FUNCTIONS | |
---|---|
render.clear() | clears the active render target |
render.constant_buffer() | create a new constant buffer. |
render.delete_render_target() | deletes a render target |
render.disable_material() | disables the currently enabled material |
render.disable_state() | disables a render state |
render.disable_texture() | disables a texture on the render state |
render.dispatch_compute() | dispatches the currently enabled compute program |
render.draw() | draws all objects matching a predicate |
render.draw_debug3d() | draws all 3d debug graphics |
render.enable_material() | enables a material |
render.enable_state() | enables a render state |
render.enable_texture() | sets a texture to the render state |
render.get_height() | gets the window height, as specified for the project |
render.get_render_target_height() | retrieve a buffer height from a render target |
render.get_render_target_width() | retrieve the buffer width from a render target |
render.get_width() | gets the window width, as specified for the project |
render.get_window_height() | gets the actual window height |
render.get_window_width() | gets the actual window width |
render.predicate() | creates a new render predicate |
render.render_target() | creates a new render target |
render.set_blend_func() | sets the blending function |
render.set_camera() | sets the current render camera to be used for rendering |
render.set_color_mask() | sets the color mask |
render.set_compute() | set the current compute program |
render.set_cull_face() | sets the cull face |
render.set_depth_func() | sets the depth test function |
render.set_depth_mask() | sets the depth mask |
render.set_listener() | set render's event listener |
render.set_polygon_offset() | sets the polygon offset |
render.set_projection() | sets the projection matrix |
render.set_render_target() | sets a render target |
render.set_render_target_size() | sets the render target size |
render.set_stencil_func() | sets the stencil test function |
render.set_stencil_mask() | sets the stencil mask |
render.set_stencil_op() | sets the stencil operator |
render.set_view() | sets the view matrix |
render.set_viewport() | sets the render viewport |
CONSTANTS | |
---|---|
render.FRUSTUM_PLANES_ALL | |
render.FRUSTUM_PLANES_SIDES | |
render.RENDER_TARGET_DEFAULT |
MESSAGES | |
---|---|
clear_color | set clear color |
draw_debug_text | draw a text on the screen |
draw_line | draw a line on the screen |
resize | resizes the window |
window_resized | reports a window size change |
render.clear(buffers)
Clear buffers in the currently enabled render target with specified value. If the render target has been created with multiple color attachments, all buffers will be cleared with the same value.
PARAMETERS
buffers |
table |
table with keys specifying which buffers to clear and values set to clear values. Available keys are:
|
EXAMPLES
Clear the color buffer and the depth buffer.render.clear({[graphics.BUFFER_TYPE_COLOR0_BIT] = vmath.vector4(0, 0, 0, 0), [graphics.BUFFER_TYPE_DEPTH_BIT] = 1})
render.constant_buffer()
Constant buffers are used to set shader program variables and are optionally passed to the render.draw()
function.
The buffer's constant elements can be indexed like an ordinary Lua table, but you can't iterate over them with pairs() or ipairs().
PARAMETERS
None
RETURNS
buffer |
constant_buffer | new constant buffer |
EXAMPLES
Set a "tint" constant in a constant buffer in the render script:local constants = render.constant_buffer()
constants.tint = vmath.vector4(1, 1, 1, 1)
render.draw(self.my_pred, {constants = constants})
local constants = render.constant_buffer()
constants.light_colors = {}
constants.light_colors[1] = vmath.vector4(1, 0, 0, 1)
constants.light_colors[2] = vmath.vector4(0, 1, 0, 1)
constants.light_colors[3] = vmath.vector4(0, 0, 1, 1)
local constants = render.constant_buffer()
constants.light_colors = {
vmath.vector4(1, 0, 0, 1)
vmath.vector4(0, 1, 0, 1)
vmath.vector4(0, 0, 1, 1)
}
-- Add more constant to the array
constants.light_colors[4] = vmath.vector4(1, 1, 1, 1)
render.delete_render_target(render_target)
Deletes a render target created by a render script. You cannot delete a render target resource.
PARAMETERS
render_target |
render_target |
render target to delete |
EXAMPLES
How to delete a render target: render.delete_render_target(self.my_render_target)
render.disable_material()
If a material is currently enabled, disable it. The name of the material must be specified in the ".render" resource set in the "game.project" setting.
PARAMETERS
None
EXAMPLES
Enable material named "glow", then draw my_pred with it.render.enable_material("glow")
render.draw(self.my_pred)
render.disable_material()
render.disable_state(state)
Disables a render state.
PARAMETERS
state |
constant |
state to disable
|
EXAMPLES
Disable face culling when drawing the tile predicate:render.disable_state(graphics.STATE_CULL_FACE)
render.draw(self.tile_pred)
render.disable_texture(binding)
Disables a texture that has previourly been enabled.
PARAMETERS
binding |
number, string, hash |
texture binding, either by texture unit, string or hash that should be disabled |
EXAMPLES
function update(self, dt)
render.enable_texture(0, self.my_render_target, graphics.BUFFER_TYPE_COLOR0_BIT)
-- draw a predicate with the render target available as texture 0 in the predicate
-- material shader.
render.draw(self.my_pred)
-- done, disable the texture
render.disable_texture(0)
end
render.dispatch_compute(x,y,z,[options])
Dispatches the currently enabled compute program. The dispatch call takes three arguments x,y,z which constitutes the 'global working group' of the compute dispatch. Together with the 'local working group' specified in the compute shader as a layout qualifier, these two sets of parameters forms the number of invocations the compute shader will execute. An optional constant buffer can be provided to override the default constants. If no constants buffer is provided, a default system constants buffer is used containing constants as defined in the compute program.
PARAMETERS
x |
number |
global work group size X |
y |
number |
global work group size Y |
z |
number |
global work group size Z |
[options] |
table |
optional table with properties:
|
EXAMPLES
function init(self)
local color_params = { format = graphics.TEXTURE_FORMAT_RGBA,
width = render.get_window_width(),
height = render.get_window_height()}
self.scene_rt = render.render_target({[graphics.BUFFER_TYPE_COLOR0_BIT] = color_params})
end
function update(self, dt)
render.set_compute("bloom")
render.enable_texture(0, self.backing_texture)
render.enable_texture(1, self.scene_rt)
render.dispatch_compute(128, 128, 1)
render.set_compute()
end
local constants = render.constant_buffer()
constants.tint = vmath.vector4(1, 1, 1, 1)
render.dispatch_compute(32, 32, 32, {constants = constants})
render.draw(predicate,[options])
Draws all objects that match a specified predicate. An optional constant buffer can be provided to override the default constants. If no constants buffer is provided, a default system constants buffer is used containing constants as defined in materials and set through go.set (or particlefx.set_constant) on visual components.
PARAMETERS
predicate |
predicate |
predicate to draw for |
[options] |
table |
optional table with properties:
|
EXAMPLES
function init(self)
-- define a predicate matching anything with material tag "my_tag"
self.my_pred = render.predicate({hash("my_tag")})
end
function update(self, dt)
-- draw everything in the my_pred predicate
render.draw(self.my_pred)
end
local constants = render.constant_buffer()
constants.tint = vmath.vector4(1, 1, 1, 1)
render.draw(self.my_pred, {constants = constants})
local frustum = self.proj * self.view
render.draw(self.my_pred, {frustum = frustum})
local frustum = self.proj * self.view
render.draw(self.my_pred, {frustum = frustum, frustum_planes = render.FRUSTUM_PLANES_ALL})
render.draw_debug3d([options])
Draws all 3d debug graphics such as lines drawn with "draw_line" messages and physics visualization.
PARAMETERS
[options] |
table |
optional table with properties:
|
EXAMPLES
function update(self, dt)
-- draw debug visualization
render.draw_debug3d()
end
render.enable_material(material_id)
If another material was already enabled, it will be automatically disabled and the specified material is used instead. The name of the material must be specified in the ".render" resource set in the "game.project" setting.
PARAMETERS
material_id |
string, hash |
material id to enable |
EXAMPLES
Enable material named "glow", then draw my_pred with it.render.enable_material("glow")
render.draw(self.my_pred)
render.disable_material()
render.enable_state(state)
Enables a particular render state. The state will be enabled until disabled.
PARAMETERS
state |
constant |
state to enable
|
EXAMPLES
Enable stencil test when drawing the gui predicate, then disable it:render.enable_state(graphics.STATE_STENCIL_TEST)
render.draw(self.gui_pred)
render.disable_state(graphics.STATE_STENCIL_TEST)
render.enable_texture(binding,handle_or_name,[buffer_type])
Sets the specified texture handle for a render target attachment or a regular texture that should be used for rendering. The texture can be bound to either a texture unit or to a sampler name by a hash or a string. A texture can be bound to multiple units and sampler names at the same time, the actual binding will be applied to the shaders when a shader program is bound. When mixing binding using both units and sampler names, you might end up in situations where two different textures will be applied to the same bind location in the shader. In this case, the texture set to the named sampler will take precedence over the unit. Note that you can bind multiple sampler names to the same texture, in case you want to reuse the same texture for differnt use-cases. It is however recommended that you use the same name everywhere for the textures that should be shared across different materials.
PARAMETERS
binding |
number, string, hash |
texture binding, either by texture unit, string or hash for the sampler name that the texture should be bound to |
handle_or_name |
texture, string, hash |
render target or texture handle that should be bound, or a named resource in the "Render Resource" table in the currently assigned .render file |
[buffer_type] |
constant |
optional buffer type from which to enable the texture. Note that this argument only applies to render targets. Defaults to graphics.BUFFER_TYPE_COLOR0_BIT . These values are supported:
|
EXAMPLES
function update(self, dt)
-- enable target so all drawing is done to it
render.set_render_target(self.my_render_target)
-- draw a predicate to the render target
render.draw(self.my_pred)
-- disable target
render.set_render_target(render.RENDER_TARGET_DEFAULT)
render.enable_texture(0, self.my_render_target, graphics.BUFFER_TYPE_COLOR0_BIT)
-- draw a predicate with the render target available as texture 0 in the predicate
-- material shader.
render.draw(self.my_pred)
end
function update(self, dt)
-- enable render target by resource id
render.set_render_target('my_rt_resource')
render.draw(self.my_pred)
render.set_render_target(render.RENDER_TARGET_DEFAULT)
render.enable_texture(0, 'my_rt_resource', graphics.BUFFER_TYPE_COLOR0_BIT)
-- draw a predicate with the render target available as texture 0 in the predicate
-- material shader.
render.draw(self.my_pred)
end
function update(self, dt)
-- bind a texture to the texture unit 0
render.enable_texture(0, self.my_texture_handle)
-- bind the same texture to a named sampler
render.enable_texture("my_texture_sampler", self.my_texture_handle)
end
render.get_height()
Returns the logical window height that is set in the "game.project" settings. Note that the actual window pixel size can change, either by device constraints or user input.
PARAMETERS
None
RETURNS
height |
number | specified window height |
EXAMPLES
Get the height of the windowlocal h = render.get_height()
render.get_render_target_height(render_target,buffer_type)
Returns the specified buffer height from a render target.
PARAMETERS
render_target |
render_target |
render target from which to retrieve the buffer height |
buffer_type |
constant |
which type of buffer to retrieve the height from
|
RETURNS
height |
number | the height of the render target buffer texture |
EXAMPLES
-- get the height of the render target color buffer
local h = render.get_render_target_height(self.target_right, graphics.BUFFER_TYPE_COLOR0_BIT)
-- get the height of a render target resource
local w = render.get_render_target_height('my_rt_resource', graphics.BUFFER_TYPE_COLOR0_BIT)
render.get_render_target_width(render_target,buffer_type)
Returns the specified buffer width from a render target.
PARAMETERS
render_target |
render_target |
render target from which to retrieve the buffer width |
buffer_type |
constant |
which type of buffer to retrieve the width from
|
RETURNS
width |
number | the width of the render target buffer texture |
EXAMPLES
-- get the width of the render target color buffer
local w = render.get_render_target_width(self.target_right, graphics.BUFFER_TYPE_COLOR0_BIT)
-- get the width of a render target resource
local w = render.get_render_target_width('my_rt_resource', graphics.BUFFER_TYPE_COLOR0_BIT)
render.get_width()
Returns the logical window width that is set in the "game.project" settings. Note that the actual window pixel size can change, either by device constraints or user input.
PARAMETERS
None
RETURNS
width |
number | specified window width (number) |
EXAMPLES
Get the width of the window.local w = render.get_width()
render.get_window_height()
Returns the actual physical window height. Note that this value might differ from the logical height that is set in the "game.project" settings.
PARAMETERS
None
RETURNS
height |
number | actual window height |
EXAMPLES
Get the actual height of the windowlocal h = render.get_window_height()
render.get_window_width()
Returns the actual physical window width. Note that this value might differ from the logical width that is set in the "game.project" settings.
PARAMETERS
None
RETURNS
width |
number | actual window width |
EXAMPLES
Get the actual width of the windowlocal w = render.get_window_width()
render.predicate(tags)
This function returns a new render predicate for objects with materials matching
the provided material tags. The provided tags are combined into a bit mask
for the predicate. If multiple tags are provided, the predicate matches materials
with all tags ANDed together.
The current limit to the number of tags that can be defined is 64
.
PARAMETERS
tags |
table |
table of tags that the predicate should match. The tags can be of either hash or string type |
RETURNS
predicate |
predicate | new predicate |
EXAMPLES
Create a new render predicate containing all visual objects that have a material with material tags "opaque" AND "smoke".local p = render.predicate({hash("opaque"), hash("smoke")})
render.render_target(name,parameters)
Creates a new render target according to the supplied specification table. The table should contain keys specifying which buffers should be created with what parameters. Each buffer key should have a table value consisting of parameters. The following parameter keys are available:
Key | Values |
---|---|
format |
graphics.TEXTURE_FORMAT_LUMINANCE graphics.TEXTURE_FORMAT_RGB graphics.TEXTURE_FORMAT_RGBA graphics.TEXTURE_FORMAT_DEPTH graphics.TEXTURE_FORMAT_STENCIL graphics.TEXTURE_FORMAT_RGBA32F graphics.TEXTURE_FORMAT_RGBA16F |
width |
number |
height |
number |
min_filter (optional) |
graphics.TEXTURE_FILTER_LINEAR graphics.TEXTURE_FILTER_NEAREST |
mag_filter (optional) |
graphics.TEXTURE_FILTER_LINEAR graphics.TEXTURE_FILTER_NEAREST |
u_wrap (optional) |
graphics.TEXTURE_WRAP_CLAMP_TO_BORDER graphics.TEXTURE_WRAP_CLAMP_TO_EDGE graphics.TEXTURE_WRAP_MIRRORED_REPEAT graphics.TEXTURE_WRAP_REPEAT |
v_wrap (optional) |
graphics.TEXTURE_WRAP_CLAMP_TO_BORDER graphics.TEXTURE_WRAP_CLAMP_TO_EDGE graphics.TEXTURE_WRAP_MIRRORED_REPEAT graphics.TEXTURE_WRAP_REPEAT |
flags (optional) |
render.TEXTURE_BIT (only applicable to depth and stencil buffers) |
render
table contains any of the BUFFER_TYPE_COLOR1_BIT
, BUFFER_TYPE_COLOR2_BIT
or BUFFER_TYPE_COLOR3_BIT
constants:
function init(self)
if graphics.BUFFER_TYPE_COLOR1_BIT == nil then
-- this devices does not support multiple color attachments
end
end
PARAMETERS
name |
string |
render target name |
parameters |
table |
table of buffer parameters, see the description for available keys and values |
RETURNS
render_target |
render_target | new render target |
EXAMPLES
How to create a new render target and draw to it:function init(self)
-- render target buffer parameters
local color_params = { format = graphics.TEXTURE_FORMAT_RGBA,
width = render.get_window_width(),
height = render.get_window_height(),
min_filter = graphics.TEXTURE_FILTER_LINEAR,
mag_filter = graphics.TEXTURE_FILTER_LINEAR,
u_wrap = graphics.TEXTURE_WRAP_CLAMP_TO_EDGE,
v_wrap = graphics.TEXTURE_WRAP_CLAMP_TO_EDGE }
local depth_params = { format = graphics.TEXTURE_FORMAT_DEPTH,
width = render.get_window_width(),
height = render.get_window_height(),
u_wrap = graphics.TEXTURE_WRAP_CLAMP_TO_EDGE,
v_wrap = graphics.TEXTURE_WRAP_CLAMP_TO_EDGE }
self.my_render_target = render.render_target({[graphics.BUFFER_TYPE_COLOR0_BIT] = color_params, [graphics.BUFFER_TYPE_DEPTH_BIT] = depth_params })
end
function update(self, dt)
-- enable target so all drawing is done to it
render.set_render_target(self.my_render_target)
-- draw a predicate to the render target
render.draw(self.my_pred)
end
function init(self)
-- render target buffer parameters
local color_params_rgba = { format = graphics.TEXTURE_FORMAT_RGBA,
width = render.get_window_width(),
height = render.get_window_height(),
min_filter = graphics.TEXTURE_FILTER_LINEAR,
mag_filter = graphics.TEXTURE_FILTER_LINEAR,
u_wrap = graphics.TEXTURE_WRAP_CLAMP_TO_EDGE,
v_wrap = graphics.TEXTURE_WRAP_CLAMP_TO_EDGE }
local color_params_float = { format = graphics.TEXTURE_FORMAT_RG32F,
width = render.get_window_width(),
height = render.get_window_height(),
min_filter = graphics.TEXTURE_FILTER_LINEAR,
mag_filter = graphics.TEXTURE_FILTER_LINEAR,
u_wrap = graphics.TEXTURE_WRAP_CLAMP_TO_EDGE,
v_wrap = graphics.TEXTURE_WRAP_CLAMP_TO_EDGE }
-- Create a render target with three color attachments
-- Note: No depth buffer is attached here
self.my_render_target = render.render_target({
[graphics.BUFFER_TYPE_COLOR0_BIT] = color_params_rgba,
[graphics.BUFFER_TYPE_COLOR1_BIT] = color_params_rgba,
[graphics.BUFFER_TYPE_COLOR2_BIT] = color_params_float, })
end
function update(self, dt)
-- enable target so all drawing is done to it
render.enable_render_target(self.my_render_target)
-- draw a predicate to the render target
render.draw(self.my_pred)
end
render.set_blend_func(source_factor,destination_factor)
Specifies the arithmetic used when computing pixel values that are written to the frame
buffer. In RGBA mode, pixels can be drawn using a function that blends the source RGBA
pixel values with the destination pixel values already in the frame buffer.
Blending is initially disabled.
source_factor
specifies which method is used to scale the source color components.
destination_factor
specifies which method is used to scale the destination color
components.
Source color components are referred to as (Rs,Gs,Bs,As).
Destination color components are referred to as (Rd,Gd,Bd,Ad).
The color specified by setting the blendcolor is referred to as (Rc,Gc,Bc,Ac).
The source scale factor is referred to as (sR,sG,sB,sA).
The destination scale factor is referred to as (dR,dG,dB,dA).
The color values have integer values between 0 and (kR,kG,kB,kA), where kc = 2mc - 1 and mc is the number of bitplanes for that color. I.e for 8 bit color depth, color values are between 0
and 255
.
Available factor constants and corresponding scale factors:
Factor constant | Scale factor (fR,fG,fB,fA) |
---|---|
graphics.BLEND_FACTOR_ZERO |
(0,0,0,0) |
graphics.BLEND_FACTOR_ONE |
(1,1,1,1) |
graphics.BLEND_FACTOR_SRC_COLOR |
(Rs/kR,Gs/kG,Bs/kB,As/kA) |
graphics.BLEND_FACTOR_ONE_MINUS_SRC_COLOR |
(1,1,1,1) - (Rs/kR,Gs/kG,Bs/kB,As/kA) |
graphics.BLEND_FACTOR_DST_COLOR |
(Rd/kR,Gd/kG,Bd/kB,Ad/kA) |
graphics.BLEND_FACTOR_ONE_MINUS_DST_COLOR |
(1,1,1,1) - (Rd/kR,Gd/kG,Bd/kB,Ad/kA) |
graphics.BLEND_FACTOR_SRC_ALPHA |
(As/kA,As/kA,As/kA,As/kA) |
graphics.BLEND_FACTOR_ONE_MINUS_SRC_ALPHA |
(1,1,1,1) - (As/kA,As/kA,As/kA,As/kA) |
graphics.BLEND_FACTOR_DST_ALPHA |
(Ad/kA,Ad/kA,Ad/kA,Ad/kA) |
graphics.BLEND_FACTOR_ONE_MINUS_DST_ALPHA |
(1,1,1,1) - (Ad/kA,Ad/kA,Ad/kA,Ad/kA) |
graphics.BLEND_FACTOR_CONSTANT_COLOR |
(Rc,Gc,Bc,Ac) |
graphics.BLEND_FACTOR_ONE_MINUS_CONSTANT_COLOR |
(1,1,1,1) - (Rc,Gc,Bc,Ac) |
graphics.BLEND_FACTOR_CONSTANT_ALPHA |
(Ac,Ac,Ac,Ac) |
graphics.BLEND_FACTOR_ONE_MINUS_CONSTANT_ALPHA |
(1,1,1,1) - (Ac,Ac,Ac,Ac) |
graphics.BLEND_FACTOR_SRC_ALPHA_SATURATE |
(i,i,i,1) where i = min(As, kA - Ad) /kA |
(graphics.BLEND_FACTOR_SRC_ALPHA, graphics.BLEND_FACTOR_ONE_MINUS_SRC_ALPHA)
is useful for
drawing with transparency when the drawn objects are sorted from farthest to nearest.
It is also useful for drawing antialiased points and lines in arbitrary order.
PARAMETERS
source_factor |
constant |
source factor |
destination_factor |
constant |
destination factor |
EXAMPLES
Set the blend func to the most common one:render.set_blend_func(graphics.BLEND_FACTOR_SRC_ALPHA, graphics.BLEND_FACTOR_ONE_MINUS_SRC_ALPHA)
render.set_camera(camera,[options])
Sets the current render camera to be used for rendering. If a render camera
has been set by the render script, the renderer will be using its projection and view matrix
during rendering. If a projection and/or view matrix has been set by the render script,
they will not be used until the current render camera has been reset by calling render.set_camera()
.
If the 'use_frustum' flag in the options table has been set to true, the renderer will automatically use the
camera frustum for frustum culling regardless of what frustum is being passed into the render.draw() function.
Note that the frustum plane option in render.draw can still be used together with the camera.
PARAMETERS
camera |
url, handle, nil |
camera id to use, or nil to reset |
[options] |
table |
optional table with properties:
|
EXAMPLES
Set the current camera to be used for renderingrender.set_camera("main:/my_go#camera")
render.draw(self.my_pred)
render.set_camera(nil)
-- The camera frustum will take precedence over the frustum plane option in render.draw
render.set_camera("main:/my_go#camera", { use_frustum = true })
-- However, we can still customize the frustum planes regardless of the camera option!
render.draw(self.my_pred, { frustum_planes = render.FRUSTUM_PLANES_ALL })
render.set_camera()
render.set_color_mask(red,green,blue,alpha)
Specifies whether the individual color components in the frame buffer is enabled for writing (true
) or disabled (false
). For example, if blue
is false
, nothing is written to the blue component of any pixel in any of the color buffers, regardless of the drawing operation attempted. Note that writing are either enabled or disabled for entire color components, not the individual bits of a component.
The component masks are all initially true
.
PARAMETERS
red |
boolean |
red mask |
green |
boolean |
green mask |
blue |
boolean |
blue mask |
alpha |
boolean |
alpha mask |
EXAMPLES
-- alpha cannot be written to frame buffer
render.set_color_mask(true, true, true, false)
render.set_compute(compute)
The name of the compute program must be specified in the ".render" resource set in the "game.project" setting. If nil (or no arguments) are passed to this function, the current compute program will instead be disabled.
PARAMETERS
compute |
string, hash, nil |
compute id to use, or nil to disable |
EXAMPLES
Enable compute program named "fractals", then dispatch it.render.set_compute("fractals")
render.enable_texture(0, self.backing_texture)
render.dispatch_compute(128, 128, 1)
render.set_compute()
render.set_cull_face(face_type)
Specifies whether front- or back-facing polygons can be culled
when polygon culling is enabled. Polygon culling is initially disabled.
If mode is graphics.FACE_TYPE_FRONT_AND_BACK
, no polygons are drawn, but other
primitives such as points and lines are drawn. The initial value for
face_type
is graphics.FACE_TYPE_BACK
.
PARAMETERS
face_type |
constant |
face type
|
EXAMPLES
How to enable polygon culling and set front face culling:render.enable_state(graphics.STATE_CULL_FACE)
render.set_cull_face(graphics.FACE_TYPE_FRONT)
render.set_depth_func(func)
Specifies the function that should be used to compare each incoming pixel depth value with the value present in the depth buffer. The comparison is performed only if depth testing is enabled and specifies the conditions under which a pixel will be drawn. Function constants:
graphics.COMPARE_FUNC_NEVER
(never passes)graphics.COMPARE_FUNC_LESS
(passes if the incoming depth value is less than the stored value)graphics.COMPARE_FUNC_LEQUAL
(passes if the incoming depth value is less than or equal to the stored value)graphics.COMPARE_FUNC_GREATER
(passes if the incoming depth value is greater than the stored value)graphics.COMPARE_FUNC_GEQUAL
(passes if the incoming depth value is greater than or equal to the stored value)graphics.COMPARE_FUNC_EQUAL
(passes if the incoming depth value is equal to the stored value)graphics.COMPARE_FUNC_NOTEQUAL
(passes if the incoming depth value is not equal to the stored value)graphics.COMPARE_FUNC_ALWAYS
(always passes)graphics.COMPARE_FUNC_LESS
.
PARAMETERS
func |
constant |
depth test function, see the description for available values |
EXAMPLES
Enable depth test and set the depth test function to "not equal".render.enable_state(graphics.STATE_DEPTH_TEST)
render.set_depth_func(graphics.COMPARE_FUNC_NOTEQUAL)
render.set_depth_mask(depth)
Specifies whether the depth buffer is enabled for writing. The supplied mask governs
if depth buffer writing is enabled (true
) or disabled (false
).
The mask is initially true
.
PARAMETERS
depth |
boolean |
depth mask |
EXAMPLES
How to turn off writing to the depth buffer:render.set_depth_mask(false)
render.set_listener(callback)
Set or remove listener. Currenly only only two type of events can arrived:
render.CONTEXT_EVENT_CONTEXT_LOST
- when rendering context lost. Rending paused and all graphics resources become invalid.
render.CONTEXT_EVENT_CONTEXT_RESTORED
- when rendering context was restored. Rendering still paused and graphics resources still
invalid but can be reloaded.
PARAMETERS
callback |
function(self, event_type), nil |
A callback that receives all render related events.
Pass nil if want to remove listener.
|
EXAMPLES
Set listener and handle render context events.--- custom.render_script
function init(self)
render.set_listener(function(self, event_type)
if event_type == render.CONTEXT_EVENT_CONTEXT_LOST then
--- Some stuff when rendering context is lost
elseif event_type == render.CONTEXT_EVENT_CONTEXT_RESTORED then
--- Start reload resources, reload game, etc.
end
end)
end
render.set_polygon_offset(factor,units)
Sets the scale and units used to calculate depth values.
If graphics.STATE_POLYGON_OFFSET_FILL
is enabled, each fragment's depth value
is offset from its interpolated value (depending on the depth value of the
appropriate vertices). Polygon offset can be used when drawing decals, rendering
hidden-line images etc.
factor
specifies a scale factor that is used to create a variable depth
offset for each polygon. The initial value is 0
.
units
is multiplied by an implementation-specific value to create a
constant depth offset. The initial value is 0
.
The value of the offset is computed as factor
× DZ
+ r
× units
DZ
is a measurement of the depth slope of the polygon which is the change in z (depth)
values divided by the change in either x or y coordinates, as you traverse a polygon.
The depth values are in window coordinates, clamped to the range [0, 1].
r
is the smallest value that is guaranteed to produce a resolvable difference.
It's value is an implementation-specific constant.
The offset is added before the depth test is performed and before the
value is written into the depth buffer.
PARAMETERS
factor |
number |
polygon offset factor |
units |
number |
polygon offset units |
EXAMPLES
render.enable_state(graphics.STATE_POLYGON_OFFSET_FILL)
render.set_polygon_offset(1.0, 1.0)
render.set_projection(matrix)
Sets the projection matrix to use when rendering.
PARAMETERS
matrix |
matrix4 |
projection matrix |
EXAMPLES
How to set the projection to orthographic with world origo at lower left, width and height as set in project settings and depth (z) between -1 and 1:render.set_projection(vmath.matrix4_orthographic(0, render.get_width(), 0, render.get_height(), -1, 1))
render.set_render_target(render_target,[options])
Sets a render target. Subsequent draw operations will be to the render target until it is replaced by a subsequent call to set_render_target. This function supports render targets created by a render script, or a render target resource.
PARAMETERS
render_target |
render_target |
render target to set. render.RENDER_TARGET_DEFAULT to set the default render target |
[options] |
table |
optional table with behaviour parameters
|
EXAMPLES
How to set a render target and draw to it and then switch back to the default render target The render target defines the depth/stencil buffers as transient, when set_render_target is called the next time the buffers may be invalidated and allow for optimisations depending on driver supportfunction update(self, dt)
-- set render target so all drawing is done to it
render.set_render_target(self.my_render_target, { transient = { graphics.BUFFER_TYPE_DEPTH_BIT, graphics.BUFFER_TYPE_STENCIL_BIT } } )
-- draw a predicate to the render target
render.draw(self.my_pred)
-- set default render target. This also invalidates the depth and stencil buffers of the current target (self.my_render_target)
-- which can be an optimisation on some hardware
render.set_render_target(render.RENDER_TARGET_DEFAULT)
end
function update(self, dt)
-- set render target by a render target resource identifier
render.set_render_target('my_rt_resource')
-- draw a predicate to the render target
render.draw(self.my_pred)
-- reset the render target to the default backbuffer
render.set_render_target(render.RENDER_TARGET_DEFAULT)
end
render.set_render_target_size(render_target,width,height)
Sets the render target size for a render target created from either a render script, or from a render target resource.
PARAMETERS
render_target |
render_target |
render target to set size for |
width |
number |
new render target width |
height |
number |
new render target height |
EXAMPLES
Resize render targets to the current window size:render.set_render_target_size(self.my_render_target, render.get_window_width(), render.get_window_height())
render.set_render_target_size('my_rt_resource', render.get_window_width(), render.get_window_height())
render.set_stencil_func(func,ref,mask)
Stenciling is similar to depth-buffering as it enables and disables drawing on a
per-pixel basis. First, GL drawing primitives are drawn into the stencil planes.
Second, geometry and images are rendered but using the stencil planes to mask out
where to draw.
The stencil test discards a pixel based on the outcome of a comparison between the
reference value ref
and the corresponding value in the stencil buffer.
func
specifies the comparison function. See the table below for values.
The initial value is graphics.COMPARE_FUNC_ALWAYS
.
ref
specifies the reference value for the stencil test. The value is clamped to
the range [0, 2n-1], where n is the number of bitplanes in the stencil buffer.
The initial value is 0
.
mask
is ANDed with both the reference value and the stored stencil value when the test
is done. The initial value is all 1
's.
Function constant:
graphics.COMPARE_FUNC_NEVER
(never passes)graphics.COMPARE_FUNC_LESS
(passes if (ref & mask) < (stencil & mask))graphics.COMPARE_FUNC_LEQUAL
(passes if (ref & mask) <= (stencil & mask))graphics.COMPARE_FUNC_GREATER
(passes if (ref & mask) > (stencil & mask))graphics.COMPARE_FUNC_GEQUAL
(passes if (ref & mask) >= (stencil & mask))graphics.COMPARE_FUNC_EQUAL
(passes if (ref & mask) = (stencil & mask))graphics.COMPARE_FUNC_NOTEQUAL
(passes if (ref & mask) != (stencil & mask))graphics.COMPARE_FUNC_ALWAYS
(always passes)PARAMETERS
func |
constant |
stencil test function, see the description for available values |
ref |
number |
reference value for the stencil test |
mask |
number |
mask that is ANDed with both the reference value and the stored stencil value when the test is done |
EXAMPLES
-- let only 0's pass the stencil test
render.set_stencil_func(graphics.COMPARE_FUNC_EQUAL, 0, 1)
render.set_stencil_mask(mask)
The stencil mask controls the writing of individual bits in the stencil buffer.
The least significant n
bits of the parameter mask
, where n
is the number of
bits in the stencil buffer, specify the mask.
Where a 1
bit appears in the mask, the corresponding
bit in the stencil buffer can be written. Where a 0
bit appears in the mask,
the corresponding bit in the stencil buffer is never written.
The mask is initially all 1
's.
PARAMETERS
mask |
number |
stencil mask |
EXAMPLES
-- set the stencil mask to all 1:s
render.set_stencil_mask(0xff)
render.set_stencil_op(sfail,dpfail,dppass)
The stencil test discards a pixel based on the outcome of a comparison between the
reference value ref
and the corresponding value in the stencil buffer.
To control the test, call render.set_stencil_func.
This function takes three arguments that control what happens to the stored stencil
value while stenciling is enabled. If the stencil test fails, no change is made to the
pixel's color or depth buffers, and sfail
specifies what happens to the stencil buffer
contents.
Operator constants:
graphics.STENCIL_OP_KEEP
(keeps the current value)graphics.STENCIL_OP_ZERO
(sets the stencil buffer value to 0)graphics.STENCIL_OP_REPLACE
(sets the stencil buffer value to ref
, as specified by render.set_stencil_func)graphics.STENCIL_OP_INCR
(increments the stencil buffer value and clamp to the maximum representable unsigned value)graphics.STENCIL_OP_INCR_WRAP
(increments the stencil buffer value and wrap to zero when incrementing the maximum representable unsigned value)graphics.STENCIL_OP_DECR
(decrements the current stencil buffer value and clamp to 0)graphics.STENCIL_OP_DECR_WRAP
(decrements the current stencil buffer value and wrap to the maximum representable unsigned value when decrementing zero)graphics.STENCIL_OP_INVERT
(bitwise inverts the current stencil buffer value)dppass
and dpfail
specify the stencil buffer actions depending on whether subsequent
depth buffer tests succeed (dppass) or fail (dpfail).
The initial value for all operators is graphics.STENCIL_OP_KEEP
.
PARAMETERS
sfail |
constant |
action to take when the stencil test fails |
dpfail |
constant |
the stencil action when the stencil test passes |
dppass |
constant |
the stencil action when both the stencil test and the depth test pass, or when the stencil test passes and either there is no depth buffer or depth testing is not enabled |
EXAMPLES
Set the stencil function to never pass and operator to always draw 1's on test fail.render.set_stencil_func(graphics.COMPARE_FUNC_NEVER, 1, 0xFF)
-- always draw 1's on test fail
render.set_stencil_op(graphics.STENCIL_OP_REPLACE, graphics.STENCIL_OP_KEEP, graphics.STENCIL_OP_KEEP)
render.set_view(matrix)
Sets the view matrix to use when rendering.
PARAMETERS
matrix |
matrix4 |
view matrix to set |
EXAMPLES
How to set the view and projection matrices according to the values supplied by a camera.function init(self)
self.view = vmath.matrix4()
self.projection = vmath.matrix4()
end
function update(self, dt)
-- set the view to the stored view value
render.set_view(self.view)
-- now we can draw with this view
end
function on_message(self, message_id, message)
if message_id == hash("set_view_projection") then
-- camera view and projection arrives here.
self.view = message.view
self.projection = message.projection
end
end
render.set_viewport(x,y,width,height)
Set the render viewport to the specified rectangle.
PARAMETERS
x |
number |
left corner |
y |
number |
bottom corner |
width |
number |
viewport width |
height |
number |
viewport height |
EXAMPLES
-- Set the viewport to the window dimensions.
render.set_viewport(0, 0, render.get_window_width(), render.get_window_height())
Set render clear color. This is the color that appears on the screen where nothing is rendered, i.e. background.
color |
vector4 |
color to use as clear color |
EXAMPLES
msg.post("@render:", "clear_color", { color = vmath.vector4(1, 0, 0, 0) } )
Draw a text on the screen. This should be used for debugging purposes only.
position |
vector3 |
position of the text |
text |
string |
the text to draw |
color |
vector4 |
color of the text |
EXAMPLES
msg.post("@render:", "draw_debug_text", { text = "Hello world!", position = vmath.vector3(200, 200, 0), color = vmath.vector4(1, 0, 0, 1) } )
Draw a line on the screen. This should mostly be used for debugging purposes.
start_point |
vector3 |
start point of the line |
end_point |
vector3 |
end point of the line |
color |
vector4 |
color of the line |
EXAMPLES
-- draw a white line from (200, 200) to (200, 300)
msg.post("@render:", "draw_line", { start_point = vmath.vector3(200, 200, 0), end_point = vmath.vector3(200, 300, 0), color = vmath.vector4(1, 1, 1, 1) } )
Set the size of the game window. Only works on desktop platforms.
height |
number |
the new window height |
width |
number |
the new window width |
EXAMPLES
msg.post("@render:", "resize", { width = 1024, height = 768 } )
Reports a change in window size. This is initiated on window resize on desktop or by orientation changes on mobile devices.
height |
number |
the new window height |
width |
number |
the new window width |
EXAMPLES
function on_message(self, message_id, message)
-- check for the message
if message_id == hash("window_resized") then
-- the window was resized.
end
end