| Name |
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| AMD_blend_minmax_factor |
| |
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| Name Strings |
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| GL_AMD_blend_minmax_factor |
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| |
| Contributors |
| |
| Graham Sellers |
| Pierre Boudier |
| |
| Contact |
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| Graham Sellers, AMD (graham.sellers 'at' amd.com) |
| |
| |
| Status |
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| Shipping. |
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| Version |
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| Last Modified Date: April 8, 2011 |
| Author Revision: 3 |
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| Number |
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| 404 |
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| Dependencies |
| |
| The extension is written against the OpenGL 4.1 (Core) Specification. |
| |
| OpenGL 1.0 is required. |
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| Overview |
| |
| The EXT_blend_minmax extension extended the GL's blending functionality |
| to allow the blending equation to be specified by the application. That |
| extension introduced the MIN_EXT and MAX_EXT blend equations, which caused the |
| result of the blend equation to become the minimum or maximum of the source |
| color and destination color, respectively. |
| |
| The MIN_EXT and MAX_EXT blend equations, however, do not include the source |
| or destination blend factors in the arguments to the min and max functions. |
| This extension provides two new blend equations that produce the minimum |
| or maximum of the products of the source color and source factor, and the |
| destination color and destination factor. |
| |
| New Procedures and Functions |
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| None. |
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| New Tokens |
| |
| Accepted by the <mode> parameter of BlendEquation and BlendEquationi, and by |
| the <modeRGB> and <modeAlpha> parameters of BlendEquationSeparate and |
| BlendEquationSeparatei: |
| |
| FACTOR_MIN_AMD 0x901C |
| FACTOR_MAX_AMD 0x901D |
| |
| Additions to Chapter 2 of the OpenGL 4.1 (Core) Specification (OpenGL Operation) |
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| None. |
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| Additions to Chapter 3 of the OpenGL 4.1 (Core) Specification (Rasterization) |
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| None. |
| |
| Additions to Chapter 4 of the OpenGL 4.1 (Core) Specification (Per-Fragment |
| Operations and the Frame Buffer) |
| |
| Modify the list of accepted tokens for <mode>, <modeRGB> and <modeAlpha> |
| in the description of BlendEquation{i} and BlendEquationSeparate{i}, p.262: |
| |
| "... <mode>, <modeRGB>, <modeAlpha> must be one of FUNC_ADD, FUNC_SUBTRACT, |
| FUNC_REVERSE_SUBTRACT, MIN, MAX, FACTOR_MIN_AMD, or FACTOR_MAX_AMD. ..." |
| |
| Add to Table 4.1: RGB and Alpha Blend Equations |
| |
| +-----------------+---------------------------+-----------------------------+ |
| | Mode | RGB Components | Alpha Component | |
| +-----------------+---------------------------+-----------------------------+ |
| | FACTOR_MIN_AMD | R = min(Rs * Sr, Rd * Dr) | A = min(As * Sa, Ad * Da) | |
| | | G = min(Gs * Sg, Gd * Dg) | | |
| | | B = min(Bs * Sb, Bd * Db) | | |
| +-----------------+---------------------------+-----------------------------+ |
| | FACTOR_MAX_AMD | R = max(Rs * Sr, Rd * Dr) | A = max(As * Sa, Ad * Da) | |
| | | G = max(Gs * Sg, Gd * Dg) | | |
| | | B = max(Bs * Sb, Bd * Db) | | |
| +-----------------+---------------------------+-----------------------------+ |
| |
| Additions to Chapter 5 of the OpenGL 4.1 (Core) Specification (Special Functions) |
| |
| None. |
| |
| Additions to Chapter 6 of the OpenGL 4.1 (Core) Specification (State and |
| State Requests) |
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| None. |
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| Additions to Appendix A of the OpenGL 4.1 (Core) Specification (Invariance) |
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| None. |
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| Additions to the AGL/GLX/WGL Specifications |
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| None. |
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| Errors |
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| None. |
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| New State |
| |
| Modify Table 6.21: Pixel Operations (cont.) p.343 |
| |
| Change entries for BLEND_EQUATION_ALPHA and BLEND_EQUATION_RGB to: |
| |
| +----------------------+---------+---------------+---------------+-------------------------+-------+ |
| | Get Value | Type | Get Command | Initial Value | Description | Sec. | |
| +----------------------+---------+---------------+---------------+-------------------------+-------+ |
| | BLEND_EQUATION_RGB | 8* x Z7 | GetIntegeri_v | FUNC_ADD | RGB Blending Equation | 4.1.7 | |
| | | | | | for Draw Buffer i | | |
| +----------------------+---------+---------------+---------------+-------------------------+-------+ |
| | BLEND_EQUATION_ALPHA | 8* x Z7 | GetIntegeri_v | FUNC_ADD | Alpha Blending Equation | 4.1.7 | |
| | | | | | for Draw Buffer i | | |
| +----------------------+---------+---------------+---------------+-------------------------+-------+ |
| |
| * Note that the only change change is that BLEND_EQUATION_RGB and |
| BLEND_EQUATION_ALPHA are now Z7 rather than Z5. |
| |
| Issues |
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| None, so far. |
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| Revision History |
| |
| Rev. Date Author Changes |
| ---- -------- -------- ----------------------------------------- |
| |
| 3 04/08/2011 gsellers Fix typo bug in Table 4.1 (caught by Brian Paul) |
| 2 09/15/2010 gsellers Update to stand against OpenGL 4.1 |
| Add token values. |
| Rename to AMD_blend_minmax_factor. |
| 1 03/16/2010 gsellers Initial draft. |