From 25c5eac5e6ca1035db1eddd7bea9ac78531da57e Mon Sep 17 00:00:00 2001 From: David Thompson Date: Thu, 28 Dec 2023 11:23:49 -0500 Subject: Delete manuals! Good riddance! These are hosted on files.dthompson.us now! --- manuals/chickadee/Render-Settings.html | 512 --------------------------------- 1 file changed, 512 deletions(-) delete mode 100644 manuals/chickadee/Render-Settings.html (limited to 'manuals/chickadee/Render-Settings.html') diff --git a/manuals/chickadee/Render-Settings.html b/manuals/chickadee/Render-Settings.html deleted file mode 100644 index 66c0eb7..0000000 --- a/manuals/chickadee/Render-Settings.html +++ /dev/null @@ -1,512 +0,0 @@ - - - - - - -Render Settings (The Chickadee Game Toolkit) - - - - - - - - - - - - - - - - - - - -
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-Next: , Previous: , Up: Graphics   [Contents][Index]

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5.3.16 Render Settings

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5.3.16.1 Blending

- -

Rendering a scene often involves drawing layers of objects that -overlap each other. Blending determines how two overlapping pixels -are combined in the final image that is rendered to the screen. The -(chickadee graphics blend) module provides a data type for -blending modes. -

-

Chickadee provides the following blend modes: -

-
-
Variable: blend:alpha
-

Blend pixels according to the values of their alpha channels. This is -the most commonly used blend mode. -

- -
-
Variable: blend:replace
-

Overwrite the output pixel color with the color being drawn. -

- -
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Variable: blend:add
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Add all pixel color values together. The more colors blended -together, the more white the final color becomes. -

- -
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Variable: blend:subtract
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Subtract all pixel color values. The more colors blended together, -the more black the final color becomes. -

- -
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Variable: blend:multiply
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- -
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Variable: blend:darken
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- -
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Variable: blend:lighten
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- -
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Variable: blend:screen
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- -

Custom blend modes can be created using the make-blend-mode procedure: -

-
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Procedure: make-blend-mode equation source-function destination-function
-

Return a new custom blend mode that applies source-function to -the source color, destination-function to the destination color, -and finally applies equation to the transformed -source/destination color values. These arguments are not -procedures, but symbolic representations of the functions that OpenGL -supports. -

-

Valid values for equation are: -

-
    -
  • add -
  • subtract -
  • reverse-subtract -
  • min -
  • max -
  • alpha-min -
  • alpha-max -
- -

Valid values for source-function are: -

-
    -
  • zero -
  • one -
  • destination-color -
  • one-minus-destination-color -
  • source-alpha-saturate -
  • source-alpha -
  • one-minus-source-alpha -
  • destination-alpha -
  • one-minus-destination-alpha -
  • constant-color -
  • one-minus-constant-color -
  • constant-alpha -
  • one-minus-constant-alpha -
- -

Valid values for destination-function are: -

-
    -
  • zero -
  • one -
  • source-color -
  • one-minus-source-color -
  • source-alpha -
  • one-minus-source-alpha -
  • destination-alpha -
  • one-minus-destination-alpha -
  • constant-color -
  • one-minus-constant-color -
  • constant-alpha -
  • one-minus-constant-alpha -
- -
- -

5.3.16.2 Polygon Modes and Culling

- -

The (chickadee graphics polygon) module provides access to the -g:polygon-mode and g:cull-face-mode render states. -

-
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Variable: fill-polygon-mode
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Completely fill in the polygon. This is the default mode. -

- -
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Variable: line-polygon-mode
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Render only the edges of the polygon. Produces a wireframe. -

- -
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Variable: point-polygon-mode
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Render only the vertex positions as points. -

- -
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Procedure: make-polygon-mode front back
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Return a new polygon mode that uses the method front for the -front face and back for the back face. The valid modes are -fill, line, and point. -

- -
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Procedure: polygon-mode? obj
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Return #t if obj is a polygon mode. -

- -
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Procedure: current-polygon-mode
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Return the current polygon mode. -

- -
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Variable: g:polygon-mode
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Render state for polygon modes (see Rendering Engine.) -

- -
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Variable: no-cull-face-mode
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Don’t cull any faces. -

- -
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Variable: back-cull-face-mode
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Cull only back faces. -

- -
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Variable: front-cull-face-mode
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Cull only front faces. -

- -
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Variable: front-and-back-cull-face-mode
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Cull both front and back faces. -

- -
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Procedure: cull-face-mode? obj
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Return #t if obj is a cull face mode. -

- -
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Procedure: cull-face-mode-front? cull-face-mode
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Return #t if cull-face-mode culls front faces. -

- -
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Procedure: cull-face-mode-back? cull-face-mode
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Return #t if cull-face-mode culls back faces. -

- -
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Procedure: current-cull-face-mode
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Return the current cull face mode. -

- -
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Variable: g:cull-face-mode
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Render state for cull face modes (see Rendering Engine.) -

- -

5.3.16.3 Depth Testing

- -

The (chickadee graphics depth) module provides access to the -g:depth-test render state. -

-
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Procedure: make-depth-test [#:write? #t] [#:function 'less-than] [#:near 0.0] [#:far 1.0]
-
-

Return a new depth test object. If write is #t, the -depth buffer will be written to during a draw call. near and -far define the min/max Z values for which depth testing may -pass. -

-

function specifies how the depth value of pixel being drawn -compares to the depth value that is already in the depth buffer. When -this comparison is true, the depth test passes and the pixel is drawn. -When it fails, the pixel is discarded. -

-

The possible values of function are: -

-
    -
  • always -
  • never -
  • equal -
  • not-equal -
  • less-than -
  • less-than-or-equal -
  • greater-than -
  • greater-than-or-equal -
- -
- -
-
Procedure: depth-test? obj
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Return #t when obj is a depth test object. -

- -
-
Procedure: depth-test-write? depth-test
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Return #t when depth-test will write to the depth buffer. -

- -
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Procedure: depth-test-function depth-test
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Return the comparison function of depth-test. -

- -
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Procedure: depth-test-near depth-test
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Return the near Z value of depth-test. -

- -
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Procedure: depth-test-far depth-test
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Return the far Z value of depth-test. -

- -
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Procedure: current-depth-test
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Return the current depth test. -

- -
-
Variable: g:depth-test
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Render state for depth tests (see Rendering Engine.) -

- -

5.3.16.4 Stencil Testing

- -

The (chickadee graphics stencil) module provides access to the -g:stencil-test render state. -

-
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Variable: default-stencil-test
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A stencil test that always passes. -

- -
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Procedure: make-stencil-test [#:mask #xFF] [#:function always] [#:function-mask #xFF] [#:reference 0] [#:on-fail keep] [#:on-depth-fail keep] [#:on-pass keep] [#:mask-front mask] [#:mask-back mask] [#:function-mask-front function-mask] [#:function-mask-back function-mask] [#:refrence-front reference] [#:reference-back reference] [#:on-fail-front on-fail] [#:on-fail-back on-fail] [#:on-depth-fail-front on-depth-fail] [#:on-depth-fail-back on-depth-fail] [#:on-pass-front on-pass] [#:on-pass-back on-pass]
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Return a new stencil test object. Different configurations can be -used for the front and back faces by using the arguments that end in -“front” or “back”. -

-

Valid values for on-pass, on-fail, and on-depth-fail -are: -

-
    -
  • zero -
  • keep -
  • replace -
  • increment -
  • increment-wrap -
  • decrement -
  • decrement-wrap -
  • invert -
- -

Valid values for function are: -

-
    -
  • always -
  • never -
  • equal -
  • not-equal -
  • less-than -
  • less-than-or-equal -
  • greater-than -
  • greater-than-or-equal -
- -
- -
-
Procedure: stencil-test? obj
-

Return #t when obj is a stencil test object. -

- -
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Procedure: stencil-test-mask-front stencil-test
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Return the front mask of stencil-test. -

- -
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Procedure: stencil-test-mask-back stencil-test
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Return the back mask of stencil-test. -

- -
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Procedure: stencil-test-function-front stencil-test
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Return the front function of stencil-test. -

- -
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Procedure: stencil-test-function-back stencil-test
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Return the back function of stencil-test. -

- -
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Procedure: stencil-test-function-mask-front stencil-test
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Return the front function-mask of stencil-test. -

- -
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Procedure: stencil-test-function-mask-back stencil-test
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Return the back function-mask of stencil-test. -

- -
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Procedure: stencil-test-reference-front stencil-test
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Return the front reference value of stencil-test. -

- -
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Procedure: stencil-test-reference-back stencil-test
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Return the back reference value of stencil-test. -

- -
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Procedure: stencil-test-on-fail-front stencil-test
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Return the front failure action of stencil-test. -

- -
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Procedure: stencil-test-on-fail-back stencil-test
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Return the back failure action of stencil-test. -

- -
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Procedure: stencil-test-on-depth-fail-front stencil-test
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Return the front depth test failure action of stencil-test. -

- -
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Procedure: stencil-test-on-depth-fail-back stencil-test
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Return the back depth test failure action of stencil-test. -

- -
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Procedure: stencil-test-on-pass-front stencil-test
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Return the front pass action of stencil-test. -

- -
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Procedure: stencil-test-on-pass-back stencil-test
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Return the back pass action of stencil-test. -

- -
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Procedure: current-stencil-test
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Return the current stencil test. -

- -
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Variable: g:stencil-test
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Render state for stencil testing (see Rendering Engine.) -

- -

5.3.16.5 Multisample Antialiasing

- -

Multisample antialiasing is a feature supported by many, but not all, -graphics cards. It is a nice easy way to improve the final frame that -the user sees, particularly in 3D scenes. The (chickadee -graphics multisample) module provides access to the -g:multisample? render state. -

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Procedure: current-multisample
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Return #t if multisampling is enabled. -

- -
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Variable: g:multisample?
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Render state for multisampling (see Rendering Engine.) -

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