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oot/src/code/PreRender.c

804 lines
32 KiB
C

/**
* @file PreRender.c
*
* This file implements various routines important to framebuffer effects, such as RDP accelerated color and depth
* buffer copies and coverage drawing. Also contains software implementations of the Video Interface anti-aliasing and
* divot filters.
*/
#include "global.h"
#include "alloca.h"
void PreRender_SetValuesSave(PreRender* this, u32 width, u32 height, void* fbuf, void* zbuf, void* cvg) {
this->widthSave = width;
this->heightSave = height;
this->fbufSave = fbuf;
this->cvgSave = cvg;
this->zbufSave = zbuf;
this->ulxSave = 0;
this->ulySave = 0;
this->lrxSave = width - 1;
this->lrySave = height - 1;
}
void PreRender_Init(PreRender* this) {
bzero(this, sizeof(PreRender));
ListAlloc_Init(&this->alloc);
}
void PreRender_SetValues(PreRender* this, u32 width, u32 height, void* fbuf, void* zbuf) {
this->width = width;
this->height = height;
this->fbuf = fbuf;
this->zbuf = zbuf;
this->ulx = 0;
this->uly = 0;
this->lrx = width - 1;
this->lry = height - 1;
}
void PreRender_Destroy(PreRender* this) {
ListAlloc_FreeAll(&this->alloc);
}
/**
* Copies RGBA16 image `img` to `imgDst`
*
* @param gfxP Display list pointer
* @param img Image to copy from
* @param imgDst Buffer to copy to
*/
void PreRender_CopyImage(PreRender* this, Gfx** gfxP, void* img, void* imgDst) {
Gfx* gfx;
s32 rowsRemaining;
s32 curRow;
s32 nRows;
LOG_UTILS_CHECK_NULL_POINTER("this", this, "../PreRender.c", 215);
LOG_UTILS_CHECK_NULL_POINTER("glistpp", gfxP, "../PreRender.c", 216);
gfx = *gfxP;
LOG_UTILS_CHECK_NULL_POINTER("glistp", gfx, "../PreRender.c", 218);
gDPPipeSync(gfx++);
// Configure the cycle type to COPY mode, disable blending
gDPSetOtherMode(gfx++,
G_AD_PATTERN | G_CD_MAGICSQ | G_CK_NONE | G_TC_CONV | G_TF_POINT | G_TT_NONE | G_TL_TILE |
G_TD_CLAMP | G_TP_NONE | G_CYC_COPY | G_PM_NPRIMITIVE,
G_AC_NONE | G_ZS_PIXEL | G_RM_NOOP | G_RM_NOOP2);
// Set the destination buffer as the color image and set the scissoring region to the entire image
gDPSetColorImage(gfx++, G_IM_FMT_RGBA, G_IM_SIZ_16b, this->width, imgDst);
gDPSetScissor(gfx++, G_SC_NON_INTERLACE, 0, 0, this->width, this->height);
// Calculate the max number of rows that can fit into TMEM at once
nRows = TMEM_SIZE / (this->width * G_IM_SIZ_16b_BYTES);
rowsRemaining = this->height;
curRow = 0;
while (rowsRemaining > 0) {
s32 uls = 0;
s32 lrs = this->width - 1;
s32 ult;
s32 lrt;
// Make sure that we don't load past the end of the source image
nRows = MIN(rowsRemaining, nRows);
// Determine the upper and lower bounds of the rect to draw
ult = curRow;
lrt = ult + nRows - 1;
// Load a horizontal strip of the source image in RGBA16 format
gDPLoadTextureTile(gfx++, img, G_IM_FMT_RGBA, G_IM_SIZ_16b, this->width, this->height, uls, ult, lrs, lrt, 0,
G_TX_NOMIRROR | G_TX_WRAP, G_TX_NOMIRROR | G_TX_WRAP, G_TX_NOMASK, G_TX_NOMASK, G_TX_NOLOD,
G_TX_NOLOD);
// Draw that horizontal strip to the destination image, dsdx is 4 << 10 for COPY mode
gSPTextureRectangle(gfx++, uls << 2, ult << 2, lrs << 2, lrt << 2, G_TX_RENDERTILE, uls << 5, ult << 5, 4 << 10,
1 << 10);
rowsRemaining -= nRows;
curRow += nRows;
}
gDPPipeSync(gfx++);
gDPSetColorImage(gfx++, G_IM_FMT_RGBA, G_IM_SIZ_16b, this->width, this->fbuf);
*gfxP = gfx;
}
/**
* Copies part of `this->fbufSave` in the region (this->ulx, this->uly), (this->lrx, this->lry) to the same location in
* `this->fbuf`.
*/
void PreRender_CopyImageRegionImpl(PreRender* this, Gfx** gfxP) {
Gfx* gfx;
s32 rowsRemaining;
s32 curRow;
s32 nRows;
LOG_UTILS_CHECK_NULL_POINTER("this", this, "../PreRender.c", 278);
LOG_UTILS_CHECK_NULL_POINTER("glistpp", gfxP, "../PreRender.c", 279);
gfx = *gfxP;
LOG_UTILS_CHECK_NULL_POINTER("glistp", gfx, "../PreRender.c", 281);
gDPPipeSync(gfx++);
// Configure the cycle type to COPY mode, disable blending
gDPSetOtherMode(gfx++,
G_AD_PATTERN | G_CD_MAGICSQ | G_CK_NONE | G_TC_CONV | G_TF_POINT | G_TT_NONE | G_TL_TILE |
G_TD_CLAMP | G_TP_NONE | G_CYC_COPY | G_PM_NPRIMITIVE,
G_AC_NONE | G_ZS_PIXEL | G_RM_NOOP | G_RM_NOOP2);
// Set the destination buffer as the color image and set the scissoring region to the destination region
gDPSetColorImage(gfx++, G_IM_FMT_RGBA, G_IM_SIZ_16b, this->width, this->fbuf);
gDPSetScissor(gfx++, G_SC_NON_INTERLACE, this->ulx, this->uly, this->lrx + 1, this->lry + 1);
// Calculate the max number of rows that can fit into TMEM at once
nRows = TMEM_SIZE / ((this->lrxSave - this->ulxSave + 1) * G_IM_SIZ_16b_BYTES);
rowsRemaining = (this->lrySave - this->ulySave) + 1;
curRow = 0;
while (rowsRemaining > 0) {
s32 ult;
s32 lrt;
s32 uly;
// Make sure that we don't load past the end of the source image
nRows = MIN(rowsRemaining, nRows);
// Determine the upper and lower bounds of the rect to draw
ult = this->ulySave + curRow;
lrt = ult + nRows - 1;
uly = this->uly + curRow;
// Load a horizontal strip of the source image in RGBA16 format
gDPLoadTextureTile(gfx++, this->fbufSave, G_IM_FMT_RGBA, G_IM_SIZ_16b, this->widthSave, this->height - 1,
this->ulxSave, ult, this->lrxSave, lrt, 0, G_TX_NOMIRROR | G_TX_WRAP,
G_TX_NOMIRROR | G_TX_WRAP, G_TX_NOMASK, G_TX_NOMASK, G_TX_NOLOD, G_TX_NOLOD);
// Draw that horizontal strip to the destination image, dsdx is 4 << 10 for COPY mode
gSPTextureRectangle(gfx++, this->ulx << 2, uly << 2, this->lrx << 2, (uly + nRows - 1) << 2, G_TX_RENDERTILE,
this->ulxSave << 5, ult << 5, 4 << 10, 1 << 10);
rowsRemaining -= nRows;
curRow += nRows;
}
// Reset the color image and scissor
gDPPipeSync(gfx++);
gDPSetColorImage(gfx++, G_IM_FMT_RGBA, G_IM_SIZ_16b, this->width, this->fbuf);
gDPSetScissor(gfx++, G_SC_NON_INTERLACE, 0, 0, this->width, this->height);
*gfxP = gfx;
}
/**
* Copies `buf` to `bufSave`, discarding the alpha channel and modulating the RGB channel by
* the color ('r', 'g', 'b', 'a')
*/
void func_800C170C(PreRender* this, Gfx** gfxP, void* buf, void* bufSave, u32 r, u32 g, u32 b, u32 a) {
Gfx* gfx;
s32 rowsRemaining;
s32 curRow;
s32 nRows;
LOG_UTILS_CHECK_NULL_POINTER("this", this, "../PreRender.c", 343);
LOG_UTILS_CHECK_NULL_POINTER("glistpp", gfxP, "../PreRender.c", 344);
gfx = *gfxP;
LOG_UTILS_CHECK_NULL_POINTER("glistp", gfx, "../PreRender.c", 346);
gDPPipeSync(gfx++);
// Set the cycle type to 1-cycle mode to use the color combiner
gDPSetOtherMode(gfx++,
G_AD_DISABLE | G_CD_DISABLE | G_CK_NONE | G_TC_FILT | G_TF_POINT | G_TT_NONE | G_TL_TILE |
G_TD_CLAMP | G_TP_NONE | G_CYC_1CYCLE | G_PM_NPRIMITIVE,
G_AC_NONE | G_ZS_PRIM | G_RM_OPA_SURF | G_RM_OPA_SURF2);
gDPSetEnvColor(gfx++, r, g, b, a);
// Redundant setting of color combiner, overwritten immediately
// Would preserve rgb exactly while replacing the alpha channel with full alpha
gDPSetCombineLERP(gfx++, 0, 0, 0, TEXEL0, 0, 0, 0, 1, 0, 0, 0, TEXEL0, 0, 0, 0, 1);
// Modulate TEXEL0 by ENVIRONMENT, replace alpha with full alpha
gDPSetCombineLERP(gfx++, TEXEL0, 0, ENVIRONMENT, 0, 0, 0, 0, 1, TEXEL0, 0, ENVIRONMENT, 0, 0, 0, 0, 1);
// Set the destination buffer as the color image and set the scissoring region to the entire image
gDPSetColorImage(gfx++, G_IM_FMT_RGBA, G_IM_SIZ_16b, this->width, bufSave);
gDPSetScissor(gfx++, G_SC_NON_INTERLACE, 0, 0, this->width, this->height);
// Calculate the max number of rows that can fit into TMEM at once
nRows = TMEM_SIZE / (this->width * G_IM_SIZ_16b_BYTES);
rowsRemaining = this->height;
curRow = 0;
while (rowsRemaining > 0) {
s32 uls = 0;
s32 lrs = this->width - 1;
s32 ult;
s32 lrt;
// Make sure that we don't load past the end of the source image
nRows = MIN(rowsRemaining, nRows);
// Determine the upper and lower bounds of the rect to draw
ult = curRow;
lrt = curRow + nRows - 1;
// Load a horizontal strip of the source image in RGBA16 format
gDPLoadTextureTile(gfx++, buf, G_IM_FMT_RGBA, G_IM_SIZ_16b, this->width, this->height, uls, ult, lrs, lrt, 0,
G_TX_NOMIRROR | G_TX_WRAP, G_TX_NOMIRROR | G_TX_WRAP, G_TX_NOMASK, G_TX_NOMASK, G_TX_NOLOD,
G_TX_NOLOD);
// Draw that horizontal strip to the destination image
gSPTextureRectangle(gfx++, uls << 2, ult << 2, (lrs + 1) << 2, (lrt + 1) << 2, G_TX_RENDERTILE, uls << 5,
ult << 5, 1 << 10, 1 << 10);
rowsRemaining -= nRows;
curRow += nRows;
}
gDPPipeSync(gfx++);
gDPSetColorImage(gfx++, G_IM_FMT_RGBA, G_IM_SIZ_16b, this->width, this->fbuf);
*gfxP = gfx;
}
/**
* Copies `fbuf` to `fbufSave`, discarding the alpha channel and leaving the rgb channel unchanged
*/
void func_800C1AE8(PreRender* this, Gfx** gfxP, void* fbuf, void* fbufSave) {
func_800C170C(this, gfxP, fbuf, fbufSave, 255, 255, 255, 255);
}
/**
* Reads the coverage values stored in the RGBA16 format `img` with dimensions `this->width`, `this->height` and
* converts it to an 8-bpp intensity image.
*
* @param gfxP Display list pointer
* @param img Image to read coverage from
* @param cvgDst Buffer to store coverage into
*/
void PreRender_CoverageRgba16ToI8(PreRender* this, Gfx** gfxP, void* img, void* cvgDst) {
Gfx* gfx;
s32 rowsRemaining;
s32 curRow;
s32 nRows;
LOG_UTILS_CHECK_NULL_POINTER("this", this, "../PreRender.c", 422);
LOG_UTILS_CHECK_NULL_POINTER("glistpp", gfxP, "../PreRender.c", 423);
gfx = *gfxP;
LOG_UTILS_CHECK_NULL_POINTER("glistp", gfx, "../PreRender.c", 425);
gDPPipeSync(gfx++);
gDPSetOtherMode(gfx++,
G_AD_DISABLE | G_CD_DISABLE | G_CK_NONE | G_TC_FILT | G_TF_POINT | G_TT_NONE | G_TL_TILE |
G_TD_CLAMP | G_TP_NONE | G_CYC_1CYCLE | G_PM_NPRIMITIVE,
G_AC_NONE | G_ZS_PRIM | G_RM_PASS | G_RM_OPA_CI2);
// Set the combiner to draw the texture as-is, discarding alpha channel
gDPSetCombineLERP(gfx++, 0, 0, 0, TEXEL0, 0, 0, 0, 0, 0, 0, 0, TEXEL0, 0, 0, 0, 0);
// Set the destination color image to the provided address
gDPSetColorImage(gfx++, G_IM_FMT_I, G_IM_SIZ_8b, this->width, cvgDst);
// Set up a scissor based on the source image
gDPSetScissor(gfx++, G_SC_NON_INTERLACE, 0, 0, this->width, this->height);
// Calculate the max number of rows that can fit into TMEM at once
nRows = TMEM_SIZE / (this->width * G_IM_SIZ_16b_BYTES);
// Set up the number of remaining rows
rowsRemaining = this->height;
curRow = 0;
while (rowsRemaining > 0) {
s32 uls = 0;
s32 lrs = this->width - 1;
s32 ult;
s32 lrt;
// Make sure that we don't load past the end of the source image
nRows = MIN(rowsRemaining, nRows);
// Determine the upper and lower bounds of the rect to draw
ult = curRow;
lrt = curRow + nRows - 1;
// Load a horizontal strip of the source image in IA16 format. Since the source image is stored in memory as
// RGBA16, the bits are reinterpreted into IA16:
//
// r g b a
// 11111 111 11 11111 1
// i a
// 11111 111 11 11111 1
//
// I = (r << 3) | (g >> 2)
// A = (g << 6) | (b << 1) | a
//
// Since it is expected that r = g = b = cvg in the source image, this results in
// I = (cvg << 3) | (cvg >> 2)
// This expands the 5-bit coverage into an 8-bit value
gDPLoadTextureTile(gfx++, img, G_IM_FMT_IA, G_IM_SIZ_16b, this->width, this->height, uls, ult, lrs, lrt, 0,
G_TX_NOMIRROR | G_TX_WRAP, G_TX_NOMIRROR | G_TX_WRAP, G_TX_NOMASK, G_TX_NOMASK, G_TX_NOLOD,
G_TX_NOLOD);
// Draw that horizontal strip to the destination image. With the combiner and blender configuration set above,
// the intensity (I) channel of the loaded IA16 texture will be written as-is to the I8 color image, each pixel
// in the final image is
// I = (cvg << 3) | (cvg >> 2)
gSPTextureRectangle(gfx++, uls << 2, ult << 2, (lrs + 1) << 2, (lrt + 1) << 2, G_TX_RENDERTILE, uls << 5,
ult << 5, 1 << 10, 1 << 10);
// Update the number of rows remaining and index of the row being drawn
rowsRemaining -= nRows;
curRow += nRows;
}
// Reset the color image to the current framebuffer
gDPPipeSync(gfx++);
gDPSetColorImage(gfx++, G_IM_FMT_RGBA, G_IM_SIZ_16b, this->width, this->fbuf);
*gfxP = gfx;
}
/**
* Saves zbuf to zbufSave
*/
void PreRender_SaveZBuffer(PreRender* this, Gfx** gfxP) {
LOG_UTILS_CHECK_NULL_POINTER("this->zbuf_save", this->zbufSave, "../PreRender.c", 481);
LOG_UTILS_CHECK_NULL_POINTER("this->zbuf", this->zbuf, "../PreRender.c", 482);
if ((this->zbufSave != NULL) && (this->zbuf != NULL)) {
PreRender_CopyImage(this, gfxP, this->zbuf, this->zbufSave);
}
}
/**
* Saves fbuf to fbufSave
*/
void PreRender_SaveFramebuffer(PreRender* this, Gfx** gfxP) {
LOG_UTILS_CHECK_NULL_POINTER("this->fbuf_save", this->fbufSave, "../PreRender.c", 495);
LOG_UTILS_CHECK_NULL_POINTER("this->fbuf", this->fbuf, "../PreRender.c", 496);
if ((this->fbufSave != NULL) && (this->fbuf != NULL)) {
func_800C1AE8(this, gfxP, this->fbuf, this->fbufSave);
}
}
/**
* Fetches the coverage of the current framebuffer into an image of the same format as the current color image, storing
* it over the framebuffer in memory.
*/
void PreRender_FetchFbufCoverage(PreRender* this, Gfx** gfxP) {
Gfx* gfx = *gfxP;
gDPPipeSync(gfx++);
// Set the blend color to full white and set maximum depth.
// It is important that at least dz is set to full here as the blender will shift memory alpha values based on the
// value of dz even if depth compare is disabled. If per-pixel depth was enabled, fill rectangle always uses 0 z/dz,
// causing a maximal shift of 4 to be applied to the memory alpha value. Full dz results in no shift, which is
// desired here.
gDPSetBlendColor(gfx++, 255, 255, 255, 8);
gDPSetPrimDepth(gfx++, 0xFFFF, 0xFFFF);
// Uses G_RM_VISCVG to blit the coverage values to the framebuffer
//
// G_RM_VISCVG is the following special render mode:
// IM_RD : Allow read-modify-write operations on the framebuffer
// FORCE_BL : Apply the blender to all pixels rather than just edges, skip the division step of the blend formula
// (G_BL_CLR_IN * G_BL_0 + G_BL_CLR_BL * G_BL_A_MEM) = G_BL_CLR_BL * G_BL_A_MEM
//
// G_BL_A_MEM ("memory alpha") is coverage (shifted into the most significant 3 bits of the 5-bit blender alpha
// input), therefore this blender configuration emits only the coverage (up to a constant factor determined by
// blend color) and discards any pixel colors. For an RGBA16 framebuffer, each of the three color channels r,g,b
// will receive the coverage value individually.
//
// Also disables other modes such as alpha compare and texture perspective correction
gDPSetOtherMode(gfx++,
G_AD_DISABLE | G_CD_DISABLE | G_CK_NONE | G_TC_FILT | G_TF_POINT | G_TT_NONE | G_TL_TILE |
G_TD_CLAMP | G_TP_NONE | G_CYC_1CYCLE | G_PM_NPRIMITIVE,
G_AC_NONE | G_ZS_PRIM | G_RM_VISCVG | G_RM_VISCVG2);
// Set up a scissor with the same dimensions as the framebuffer
gDPSetScissor(gfx++, G_SC_NON_INTERLACE, 0, 0, this->width, this->height);
// Fill rectangle to obtain the coverage values as an RGBA16 image
gDPFillRectangle(gfx++, 0, 0, this->width, this->height);
gDPPipeSync(gfx++);
*gfxP = gfx;
}
/**
* Draws the coverage of the current framebuffer `this->fbuf` to an I8 image at `this->cvgSave`. Overwrites
* `this->fbuf` in the process.
*/
void PreRender_DrawCoverage(PreRender* this, Gfx** gfxP) {
PreRender_FetchFbufCoverage(this, gfxP);
LOG_UTILS_CHECK_NULL_POINTER("this->cvg_save", this->cvgSave, "../PreRender.c", 532);
if (this->cvgSave != NULL) {
PreRender_CoverageRgba16ToI8(this, gfxP, this->fbuf, this->cvgSave);
}
}
/**
* Restores zbufSave to zbuf
*/
void PreRender_RestoreZBuffer(PreRender* this, Gfx** gfxP) {
PreRender_CopyImage(this, gfxP, this->zbufSave, this->zbuf);
}
/**
* Draws a full-screen image to the current framebuffer, that sources the rgb channel from `this->fbufSave` and
* the alpha channel from `this->cvgSave` modulated by environment color.
*/
void func_800C213C(PreRender* this, Gfx** gfxP) {
Gfx* gfx;
s32 rowsRemaining;
s32 curRow;
s32 nRows;
s32 rtile = 1;
if (this->cvgSave != NULL) {
LOG_UTILS_CHECK_NULL_POINTER("this", this, "../PreRender.c", 563);
LOG_UTILS_CHECK_NULL_POINTER("glistpp", gfxP, "../PreRender.c", 564);
gfx = *gfxP;
LOG_UTILS_CHECK_NULL_POINTER("glistp", gfx, "../PreRender.c", 566);
gDPPipeSync(gfx++);
gDPSetEnvColor(gfx++, 255, 255, 255, 32);
// Effectively disable blending in both cycles. It's 2-cycle so that TEXEL1 can be used to point to a different
// texture tile.
gDPSetOtherMode(gfx++,
G_AD_DISABLE | G_CD_DISABLE | G_CK_NONE | G_TC_FILT | G_TF_POINT | G_TT_NONE | G_TL_TILE |
G_TD_CLAMP | G_TP_NONE | G_CYC_2CYCLE | G_PM_NPRIMITIVE,
G_AC_NONE | G_ZS_PRIM | AA_EN | CVG_DST_CLAMP | ZMODE_OPA | CVG_X_ALPHA |
GBL_c1(G_BL_CLR_IN, G_BL_0, G_BL_CLR_IN, G_BL_1) |
GBL_c2(G_BL_CLR_IN, G_BL_0, G_BL_CLR_IN, G_BL_1));
// Set up the color combiner: first cycle: TEXEL0, TEXEL1 + ENVIRONMENT; second cycle: G_CC_PASS2
gDPSetCombineLERP(gfx++, 0, 0, 0, TEXEL0, 1, 0, TEXEL1, ENVIRONMENT, 0, 0, 0, COMBINED, 0, 0, 0, COMBINED);
nRows = 4;
rowsRemaining = this->height;
curRow = 0;
while (rowsRemaining > 0) {
s32 uls = 0;
s32 lrs = this->width - 1;
s32 ult;
s32 lrt;
// Make sure that we don't load past the end of the source image
nRows = MIN(rowsRemaining, nRows);
// Determine the upper and lower bounds of the rect to draw
ult = curRow;
lrt = curRow + nRows - 1;
// Load the frame buffer line
gDPLoadMultiTile(gfx++, this->fbufSave, 0x0000, G_TX_RENDERTILE, G_IM_FMT_RGBA, G_IM_SIZ_16b, this->width,
this->height, uls, ult, lrs, lrt, 0, G_TX_NOMIRROR | G_TX_WRAP, G_TX_NOMIRROR | G_TX_WRAP,
G_TX_NOMASK, G_TX_NOMASK, G_TX_NOLOD, G_TX_NOLOD);
// Load the coverage line
gDPLoadMultiTile(gfx++, this->cvgSave, 0x0160, rtile, G_IM_FMT_I, G_IM_SIZ_8b, this->width, this->height,
uls, ult, lrs, lrt, 0, G_TX_NOMIRROR | G_TX_WRAP, G_TX_NOMIRROR | G_TX_WRAP, G_TX_NOMASK,
G_TX_NOMASK, G_TX_NOLOD, G_TX_NOLOD);
// Draw a texture for which the rgb channels come from the framebuffer and the alpha channel comes from
// coverage, modulated by env color
gSPTextureRectangle(gfx++, uls << 2, ult << 2, (lrs + 1) << 2, (lrt + 1) << 2, G_TX_RENDERTILE, uls << 5,
ult << 5, 1 << 10, 1 << 10);
rowsRemaining -= nRows;
curRow += nRows;
}
gDPPipeSync(gfx++);
*gfxP = gfx;
}
}
/**
* Copies fbufSave to fbuf
*/
void PreRender_RestoreFramebuffer(PreRender* this, Gfx** gfxP) {
PreRender_CopyImage(this, gfxP, this->fbufSave, this->fbuf);
}
/**
* Copies part of `this->fbufSave` in the region (this->ulx, this->uly), (this->lrx, this->lry) to the same location in
* `this->fbuf`.
*/
void PreRender_CopyImageRegion(PreRender* this, Gfx** gfxP) {
PreRender_CopyImageRegionImpl(this, gfxP);
}
/**
* Applies the Video Interface anti-aliasing of silhouette edges to an image.
*
* This filter performs a linear interpolation on partially covered pixels between the current pixel color (called
* foreground color) and a "background" pixel color obtained by sampling fully covered pixels at the six highlighted
* points in the following 5x3 neighborhood:
* _ _ _ _ _
* | o o |
* | o X o |
* | o o |
* ‾ ‾ ‾ ‾ ‾
* Whether a pixel is partially covered is determined by reading the coverage values associated with the image.
* Coverage is a measure of how many subpixels the last drawn primitive covered. A fully covered pixel is one with a
* full coverage value, the entire pixel was covered by the primitive.
* The background color is calculated as the average of the "penultimate" minimum and maximum colors in the 5x3
* neighborhood.
*
* The final color is calculated by interpolating the foreground and background color weighted by the coverage:
* OutputColor = cvg * ForeGround + (1.0 - cvg) * BackGround
*
* This is a software implementation of the same algorithm used in the Video Interface hardware when Anti-Aliasing is
* enabled in the VI Control Register.
*
* Patent describing the algorithm:
*
* Gossett, C. P., & van Hook, T. J. (Filed 1995, Published 1998)
* Antialiasing of silhouette edges (USOO5742277A)
* U.S. Patent and Trademark Office
* Expired 2015-10-06
* https://patents.google.com/patent/US5742277A/en
*
* @param this PreRender instance
* @param x Center pixel x
* @param y Center pixel y
*/
void PreRender_AntiAliasFilter(PreRender* this, s32 x, s32 y) {
s32 i;
s32 j;
s32 buffCvg[5 * 3];
s32 buffR[5 * 3];
s32 buffG[5 * 3];
s32 buffB[5 * 3];
s32 xi;
s32 yi;
s32 pad;
s32 pmaxR;
s32 pmaxG;
s32 pmaxB;
s32 pminR;
s32 pminG;
s32 pminB;
Color_RGBA16 pxIn;
Color_RGBA16 pxOut;
u32 outR;
u32 outG;
u32 outB;
// Extract pixels in the 5x3 neighborhood
for (i = 0; i < 5 * 3; i++) {
xi = x + (i % 5) - 2;
yi = y + (i / 5) - 1;
// Clamp coordinates to the edges of the image
if (xi < 0) {
xi = 0;
} else if (xi > (this->width - 1)) {
xi = this->width - 1;
}
if (yi < 0) {
yi = 0;
} else if (yi > (this->height - 1)) {
yi = this->height - 1;
}
// Extract color channels for each pixel, convert 5-bit color channels to 8-bit
pxIn.rgba = this->fbufSave[xi + yi * this->width];
buffR[i] = (pxIn.r << 3) | (pxIn.r >> 2);
buffG[i] = (pxIn.g << 3) | (pxIn.g >> 2);
buffB[i] = (pxIn.b << 3) | (pxIn.b >> 2);
buffCvg[i] = this->cvgSave[xi + yi * this->width] >> 5;
}
if (buffCvg[7] == 7) {
PRINTF("Error, should not be in here \n");
return;
}
pmaxR = pminR = buffR[7];
pmaxG = pminG = buffG[7];
pmaxB = pminB = buffB[7];
// For each neighbor
for (i = 1; i < 5 * 3; i += 2) {
// Only sample fully covered pixels
if (buffCvg[i] == 7) {
// Determine "Penultimate Maximum" Value
// If current maximum is less than this neighbor
if (pmaxR < buffR[i]) {
// For each neighbor (again)
for (j = 1; j < 5 * 3; j += 2) {
// If not the neighbor we were at before, and this neighbor has a larger value and this pixel is
// fully covered, that means the neighbor at `i` is the "penultimate maximum"
if ((i != j) && (buffR[j] >= buffR[i]) && (buffCvg[j] == 7)) {
pmaxR = buffR[i];
}
}
}
if (pmaxG < buffG[i]) {
for (j = 1; j < 5 * 3; j += 2) {
if ((i != j) && (buffG[j] >= buffG[i]) && (buffCvg[j] == 7)) {
pmaxG = buffG[i];
}
}
}
if (pmaxB < buffB[i]) {
for (j = 1; j < 5 * 3; j += 2) {
if ((i != j) && (buffB[j] >= buffB[i]) && (buffCvg[j] == 7)) {
pmaxB = buffB[i];
}
}
}
if (1) {}
// Determine "Penultimate Minimum" Value
// Same as above with inverted conditions
if (pminR > buffR[i]) {
for (j = 1; j < 5 * 3; j += 2) {
if ((i != j) && (buffR[j] <= buffR[i]) && (buffCvg[j] == 7)) {
pminR = buffR[i];
}
}
}
if (pminG > buffG[i]) {
for (j = 1; j < 5 * 3; j += 2) {
if ((i != j) && (buffG[j] <= buffG[i]) && (buffCvg[j] == 7)) {
pminG = buffG[i];
}
}
}
if (pminB > buffB[i]) {
for (j = 1; j < 5 * 3; j += 2) {
if ((i != j) && (buffB[j] <= buffB[i]) && (buffCvg[j] == 7)) {
pminB = buffB[i];
}
}
}
}
}
// The background color is determined by averaging the penultimate minimum and maximum pixels, and subtracting the
// ForeGround color:
// BackGround = (pMax + pMin) - (ForeGround) * 2
// OutputColor = cvg * ForeGround + (1.0 - cvg) * BackGround
outR = buffR[7] + ((s32)((7 - buffCvg[7]) * (pmaxR + pminR - (buffR[7] * 2)) + 4) >> 3);
outG = buffG[7] + ((s32)((7 - buffCvg[7]) * (pmaxG + pminG - (buffG[7] * 2)) + 4) >> 3);
outB = buffB[7] + ((s32)((7 - buffCvg[7]) * (pmaxB + pminB - (buffB[7] * 2)) + 4) >> 3);
pxOut.r = outR >> 3;
pxOut.g = outG >> 3;
pxOut.b = outB >> 3;
pxOut.a = 1;
this->fbufSave[x + y * this->width] = pxOut.rgba;
}
// Selects the median value from a1, a2, a3
#define MEDIAN3(a1, a2, a3) \
(((a2) >= (a1)) ? (((a3) >= (a2)) ? (a2) : (((a1) >= (a3)) ? (a1) : (a3))) \
: (((a2) >= (a3)) ? (a2) : (((a3) >= (a1)) ? (a1) : (a3))))
/**
* Applies the Video Interface divot filter to an image.
*
* This filter removes "divots" in an anti-aliased image, single-pixel holes created when many boundary edges all
* occupy a single pixel. The algorithm removes these by sliding a 3-pixel-wide window across each row of pixels and
* replaces the center pixel color with the median pixel color in the window.
*
* This is a software implementation of the same algorithm used in the Video Interface hardware when OS_VI_DIVOT_ON is
* set in the VI Control Register.
*
* @param this PreRender instance
*/
void PreRender_DivotFilter(PreRender* this) {
s32 x;
s32 y;
s32 pad1;
u8* buffR = alloca(this->width);
u8* buffG = alloca(this->width);
u8* buffB = alloca(this->width);
s32 pad2[3];
s32 pxR;
s32 pxG;
s32 pxB;
for (y = 0; y < this->height; y++) {
// The divot filter is applied row-by-row as it only needs to use pixels that are horizontally adjacent
// Decompose each pixel into color channels
for (x = 0; x < this->width; x++) {
Color_RGBA16 pxIn;
pxIn.rgba = this->fbufSave[x + y * this->width];
buffR[x] = pxIn.r;
buffG[x] = pxIn.g;
buffB[x] = pxIn.b;
}
// Apply the divot filter itself. For pixels with partial coverage, the filter selects the median value from a
// window of 3 pixels in a horizontal row and uses that as the value for the center pixel.
for (x = 1; x < this->width - 1; x++) {
Color_RGBA16 pxOut;
s32 cvg = this->cvgSave[x + y * this->width];
// Reject pixels with full coverage. The hardware video filter divot circuit checks if all 3 pixels in the
// window have partial coverage, here only the center pixel is checked.
cvg >>= 5;
if (cvg == 7) {
continue;
}
// This condition is checked before entering this function, it will always pass if it runs.
if ((R_HREG_MODE == HREG_MODE_PRERENDER ? R_PRERENDER_DIVOT_CONTROL : 0) != 0) {
if ((R_HREG_MODE == HREG_MODE_PRERENDER ? R_PRERENDER_DIVOT_CONTROL : 0) != 0) {}
if ((R_HREG_MODE == HREG_MODE_PRERENDER ? R_PRERENDER_DIVOT_CONTROL : 0) ==
PRERENDER_DIVOT_PARTIAL_CVG_RED) {
// Fill the pixel with full red, likely for debugging
pxR = 31;
pxG = 0;
pxB = 0;
} else {
// Prepare sampling window
u8* windowR = &buffR[x - 1];
u8* windowG = &buffG[x - 1];
u8* windowB = &buffB[x - 1];
if ((R_HREG_MODE == HREG_MODE_PRERENDER ? R_PRERENDER_DIVOT_CONTROL : 0) ==
PRERENDER_DIVOT_PRINT_COLOR) {
PRINTF("red=%3d %3d %3d %3d grn=%3d %3d %3d %3d blu=%3d %3d %3d %3d \n", windowR[0], windowR[1],
windowR[2], MEDIAN3(windowR[0], windowR[1], windowR[2]), windowG[0], windowG[1],
windowG[2], MEDIAN3(windowG[0], windowG[1], windowG[2]), windowB[0], windowB[1],
windowB[2], MEDIAN3(windowB[0], windowB[1], windowB[2]));
}
// Sample the median value from the 3 pixel wide window
// (Both blocks contain the same code)
if ((R_HREG_MODE == HREG_MODE_PRERENDER ? R_PRERENDER_DIVOT_CONTROL : 0) ==
PRERENDER_DIVOT_ALTERNATE_COLOR) {
pxR = MEDIAN3(windowR[0], windowR[1], windowR[2]);
pxG = MEDIAN3(windowG[0], windowG[1], windowG[2]);
pxB = MEDIAN3(windowB[0], windowB[1], windowB[2]);
} else {
pxR = MEDIAN3(windowR[0], windowR[1], windowR[2]);
pxG = MEDIAN3(windowG[0], windowG[1], windowG[2]);
pxB = MEDIAN3(windowB[0], windowB[1], windowB[2]);
}
}
pxOut.r = pxR;
pxOut.g = pxG;
pxOut.b = pxB;
pxOut.a = 1;
}
this->fbufSave[x + y * this->width] = pxOut.rgba;
}
}
}
/**
* Applies the Video Interface anti-aliasing filter and (optionally) the divot filter to `this->fbufSave` using
* `this->cvgSave`
*/
void PreRender_ApplyFilters(PreRender* this) {
s32 x;
s32 y;
if ((this->cvgSave != NULL) && (this->fbufSave != NULL)) {
// Apply AA filter
for (y = 0; y < this->height; y++) {
for (x = 0; x < this->width; x++) {
s32 cvg = this->cvgSave[x + y * this->width];
cvg >>= 5;
cvg++;
if (cvg != 8) {
// If this pixel has only partial coverage, perform the Video Filter interpolation on it
PreRender_AntiAliasFilter(this, x, y);
}
}
}
if ((R_HREG_MODE == HREG_MODE_PRERENDER ? R_PRERENDER_DIVOT_CONTROL : 0) != 0) {
// Apply divot filter
PreRender_DivotFilter(this);
}
}
}