D3d deep test and Alpha hybrid

1. depth test a) depth buffer: A memory buffer for the depth information of each pixel on the screen. d3d determines whether to draw the current pixel by comparing the depth of the currently drawn pixel point and the depth value of the corresponding depth buffer point. b) d3dpresent_parameters. autodepthstencilformat = d3dfmt_d16 indicates that the depth value is enabled by 16-bit binary: pdevice-> setrenderstate (d3drs_zenable, true); the depth test function: d3drs_zfunc:

D3dcmp_never	Always returns false
D3dcmp_less (commonly used)	Returns true if it is less than the corresponding value of the depth buffer.
D3dcmp_equal	Equal
D3dcmp_lessequal	Less than or equal
D3dcmp_greater	Greater
D3dcmp_notequal	Not equal
D3dcmp_greaterequal	Greater than or equal
D3dcmp_always	Always returns true

Update Buffer: Keep the depth buffer unchanged or use the depth value of the current pixel to update pdevice-> setrenderstate (d3drs_zwriteenable, true); 2. alpha hybrid a) Principle: color = (rgbsrc * ksrc) OP (rgbdst * kdst) the most common method: color = (rgbsrc * alphasrc) + (rgbdst * (1-alphasrc) b) Application Enabling: pdevice-> setrenderstate (d3drs_alphablendenable, true );

Blend mode Factor	Description
D3dblend_zero	(0, 0, 0, 0)
D3dblend_one	(1, 1, 1, 1)
D3dblend_srccolor	(RS, GS, BS,)
D3dblend_invsrccolor	(1-rs, 1-gs, 1-bs, 1-)
D3dblend_srcalpha	(As,)
D3dblend_invsrcalpha	(1-as, 1-as, 1-as, 1-)
D3dblend_destalpha	(AD, AD)
D3dblend_invdestalpha	(1-ad, 1-ad, 1-ad, 1-AD)
D3dblend_destcolor	(Rd, Gd, BD, AD)
D3dblend_invdestcolor	(1-rd, 1-gd, 1-bd, 1-AD)
D3dblend_srcalphasat	(F, 1); F = min (AS, 1-AD)

Alpha hybrid method

D3dblendop_add	Add the source computing result to the color buffer Calculation Result
D3dblendop_subtract	Source computing result minus color buffer Calculation Result
D3dblendop_revsubtract	Color buffer calculation result minus source Calculation Result
D3dblendop_min	Min (source calculation result, color buffer calculation result)
D3dblendop_max	Max (source computing result, color buffer calculation result)

Color = (rgbsrc * alphasrc) + (rgbdst * (1-alphasrc) setting example: pdevice-> setrenderstate (d3drs_srcblend, expiration); pdevice-> setrenderstate (d3drs_destblend, d3dblend_invsrcalpha); pdevice-> setrenderstate (d3dblendop, d3dblendop_add); (default value, optional) 3. alpha test A) The principle is based on the Alpha test conditions to determine whether to draw the current pixel. Color buffering is not required, so the speed is faster than that of Alpha mixing. b) Application Enabling: pdevice-> setrenderstate (d3drs_alphatestenable, true); Alpha test function d3dcmp_func enumeration; default value: d3dcmp_always reference value: pdevice-> setrenderstate (d3drs_alpharef, 0x00000081 );