/*************************************************************************** rendutil.c Core rendering utilities. Copyright Nicola Salmoria and the MAME Team. Visit http://mamedev.org for licensing and usage restrictions. ***************************************************************************/ #include "render.h" #include "rendutil.h" #include "png.h" /*************************************************************************** FUNCTION PROTOTYPES ***************************************************************************/ /* utilities */ static void resample_argb_bitmap_average(UINT32 *dest, UINT32 drowpixels, UINT32 dwidth, UINT32 dheight, const UINT32 *source, UINT32 srowpixels, UINT32 swidth, UINT32 sheight, const render_color *color, UINT32 dx, UINT32 dy); static void resample_argb_bitmap_bilinear(UINT32 *dest, UINT32 drowpixels, UINT32 dwidth, UINT32 dheight, const UINT32 *source, UINT32 srowpixels, UINT32 swidth, UINT32 sheight, const render_color *color, UINT32 dx, UINT32 dy); static void copy_png_to_bitmap(bitmap_t *bitmap, const png_info *png, int *hasalpha); static void copy_png_alpha_to_bitmap(bitmap_t *bitmap, const png_info *png, int *hasalpha); /*************************************************************************** INLINE FUNCTIONS ***************************************************************************/ /*------------------------------------------------- compute_brightness - compute the effective brightness for an RGB pixel -------------------------------------------------*/ INLINE UINT8 compute_brightness(rgb_t rgb) { return (RGB_RED(rgb) * 222 + RGB_GREEN(rgb) * 707 + RGB_BLUE(rgb) * 71) / 1000; } /*************************************************************************** RENDER UTILITIES ***************************************************************************/ /*------------------------------------------------- render_resample_argb_bitmap_hq - perform a high quality resampling of a texture -------------------------------------------------*/ void render_resample_argb_bitmap_hq(void *dest, UINT32 drowpixels, UINT32 dwidth, UINT32 dheight, const bitmap_t *source, const rectangle *orig_sbounds, const render_color *color) { UINT32 swidth, sheight; const UINT32 *sbase; rectangle sbounds; UINT32 dx, dy; if (dwidth == 0 || dheight == 0) return; /* compute the real source bounds */ if (orig_sbounds != NULL) sbounds = *orig_sbounds; else { sbounds.min_x = sbounds.min_y = 0; sbounds.max_x = source->width; sbounds.max_y = source->height; } /* adjust the source base */ sbase = (const UINT32 *)source->base + sbounds.min_y * source->rowpixels + sbounds.min_x; /* determine the steppings */ swidth = sbounds.max_x - sbounds.min_x; sheight = sbounds.max_y - sbounds.min_y; dx = (swidth << 12) / dwidth; dy = (sheight << 12) / dheight; /* if the source is higher res than the target, use full averaging */ if (dx > 0x1000 || dy > 0x1000) resample_argb_bitmap_average(dest, drowpixels, dwidth, dheight, sbase, source->rowpixels, swidth, sheight, color, dx, dy); else resample_argb_bitmap_bilinear(dest, drowpixels, dwidth, dheight, sbase, source->rowpixels, swidth, sheight, color, dx, dy); } /*------------------------------------------------- resample_argb_bitmap_average - resample a texture by performing a true weighted average over all contributing pixels -------------------------------------------------*/ static void resample_argb_bitmap_average(UINT32 *dest, UINT32 drowpixels, UINT32 dwidth, UINT32 dheight, const UINT32 *source, UINT32 srowpixels, UINT32 swidth, UINT32 sheight, const render_color *color, UINT32 dx, UINT32 dy) { UINT64 sumscale = (UINT64)dx * (UINT64)dy; UINT32 r, g, b, a; UINT32 x, y; /* precompute premultiplied R/G/B/A factors */ r = color->r * color->a * 256.0; g = color->g * color->a * 256.0; b = color->b * color->a * 256.0; a = color->a * 256.0; /* loop over the target vertically */ for (y = 0; y < dheight; y++) { UINT32 starty = y * dy; /* loop over the target horizontally */ for (x = 0; x < dwidth; x++) { UINT64 sumr = 0, sumg = 0, sumb = 0, suma = 0; UINT32 startx = x * dx; UINT32 xchunk, ychunk; UINT32 curx, cury; UINT32 yremaining = dy; /* accumulate all source pixels that contribute to this pixel */ for (cury = starty; yremaining; cury += ychunk) { UINT32 xremaining = dx; /* determine the Y contribution, clamping to the amount remaining */ ychunk = 0x1000 - (cury & 0xfff); if (ychunk > yremaining) ychunk = yremaining; yremaining -= ychunk; /* loop over all source pixels in the X direction */ for (curx = startx; xremaining; curx += xchunk) { UINT32 factor; UINT32 pix; /* determine the X contribution, clamping to the amount remaining */ xchunk = 0x1000 - (curx & 0xfff); if (xchunk > xremaining) xchunk = xremaining; xremaining -= xchunk; /* total contribution = x * y */ factor = xchunk * ychunk; /* fetch the source pixel */ pix = source[(cury >> 12) * srowpixels + (curx >> 12)]; /* accumulate the RGBA values */ sumr += factor * RGB_RED(pix); sumg += factor * RGB_GREEN(pix); sumb += factor * RGB_BLUE(pix); suma += factor * RGB_ALPHA(pix); } } /* apply scaling */ suma = (suma / sumscale) * a / 256; sumr = (sumr / sumscale) * r / 256; sumg = (sumg / sumscale) * g / 256; sumb = (sumb / sumscale) * b / 256; /* if we're translucent, add in the destination pixel contribution */ if (a < 256) { UINT32 dpix = dest[y * drowpixels + x]; suma += RGB_ALPHA(dpix) * (256 - a); sumr += RGB_RED(dpix) * (256 - a); sumg += RGB_GREEN(dpix) * (256 - a); sumb += RGB_BLUE(dpix) * (256 - a); } /* store the target pixel, dividing the RGBA values by the overall scale factor */ dest[y * drowpixels + x] = MAKE_ARGB(suma, sumr, sumg, sumb); } } } /*------------------------------------------------- resample_argb_bitmap_bilinear - perform texture sampling via a bilinear filter -------------------------------------------------*/ static void resample_argb_bitmap_bilinear(UINT32 *dest, UINT32 drowpixels, UINT32 dwidth, UINT32 dheight, const UINT32 *source, UINT32 srowpixels, UINT32 swidth, UINT32 sheight, const render_color *color, UINT32 dx, UINT32 dy) { UINT32 maxx = swidth << 12, maxy = sheight << 12; UINT32 r, g, b, a; UINT32 x, y; /* precompute premultiplied R/G/B/A factors */ r = color->r * color->a * 256.0; g = color->g * color->a * 256.0; b = color->b * color->a * 256.0; a = color->a * 256.0; /* loop over the target vertically */ for (y = 0; y < dheight; y++) { UINT32 starty = y * dy; /* loop over the target horizontally */ for (x = 0; x < dwidth; x++) { UINT32 startx = x * dx; UINT32 pix0, pix1, pix2, pix3; UINT32 sumr, sumg, sumb, suma; UINT32 nextx, nexty; UINT32 curx, cury; UINT32 factor; /* adjust start to the center; note that this math will tend to produce */ /* negative results on the first pixel, which is why we clamp below */ curx = startx + dx / 2 - 0x800; cury = starty + dy / 2 - 0x800; /* compute the neighboring pixel */ nextx = curx + 0x1000; nexty = cury + 0x1000; /* fetch the four relevant pixels */ pix0 = pix1 = pix2 = pix3 = 0; if ((INT32)cury >= 0 && cury < maxy && (INT32)curx >= 0 && curx < maxx) pix0 = source[(cury >> 12) * srowpixels + (curx >> 12)]; if ((INT32)cury >= 0 && cury < maxy && (INT32)nextx >= 0 && nextx < maxx) pix1 = source[(cury >> 12) * srowpixels + (nextx >> 12)]; if ((INT32)nexty >= 0 && nexty < maxy && (INT32)curx >= 0 && curx < maxx) pix2 = source[(nexty >> 12) * srowpixels + (curx >> 12)]; if ((INT32)nexty >= 0 && nexty < maxy && (INT32)nextx >= 0 && nextx < maxx) pix3 = source[(nexty >> 12) * srowpixels + (nextx >> 12)]; /* compute the x/y scaling factors */ curx &= 0xfff; cury &= 0xfff; /* contributions from pixel 0 (top,left) */ factor = (0x1000 - curx) * (0x1000 - cury); sumr = factor * RGB_RED(pix0); sumg = factor * RGB_GREEN(pix0); sumb = factor * RGB_BLUE(pix0); suma = factor * RGB_ALPHA(pix0); /* contributions from pixel 1 (top,right) */ factor = curx * (0x1000 - cury); sumr += factor * RGB_RED(pix1); sumg += factor * RGB_GREEN(pix1); sumb += factor * RGB_BLUE(pix1); suma += factor * RGB_ALPHA(pix1); /* contributions from pixel 2 (bottom,left) */ factor = (0x1000 - curx) * cury; sumr += factor * RGB_RED(pix2); sumg += factor * RGB_GREEN(pix2); sumb += factor * RGB_BLUE(pix2); suma += factor * RGB_ALPHA(pix2); /* contributions from pixel 3 (bottom,right) */ factor = curx * cury; sumr += factor * RGB_RED(pix3); sumg += factor * RGB_GREEN(pix3); sumb += factor * RGB_BLUE(pix3); suma += factor * RGB_ALPHA(pix3); /* apply scaling */ suma = (suma >> 24) * a / 256; sumr = (sumr >> 24) * r / 256; sumg = (sumg >> 24) * g / 256; sumb = (sumb >> 24) * b / 256; /* if we're translucent, add in the destination pixel contribution */ if (a < 256) { UINT32 dpix = dest[y * drowpixels + x]; suma += RGB_ALPHA(dpix) * (256 - a); sumr += RGB_RED(dpix) * (256 - a); sumg += RGB_GREEN(dpix) * (256 - a); sumb += RGB_BLUE(dpix) * (256 - a); } /* store the target pixel, dividing the RGBA values by the overall scale factor */ dest[y * drowpixels + x] = MAKE_ARGB(suma, sumr, sumg, sumb); } } } /*------------------------------------------------- render_clip_line - clip a line to a rectangle -------------------------------------------------*/ int render_clip_line(render_bounds *bounds, const render_bounds *clip) { /* loop until we get a final result */ while (1) { UINT8 code0 = 0, code1 = 0; UINT8 thiscode; float x, y; /* compute Cohen Sutherland bits for first coordinate */ if (bounds->y0 > clip->y1) code0 |= 1; if (bounds->y0 < clip->y0) code0 |= 2; if (bounds->x0 > clip->x1) code0 |= 4; if (bounds->x0 < clip->x0) code0 |= 8; /* compute Cohen Sutherland bits for second coordinate */ if (bounds->y1 > clip->y1) code1 |= 1; if (bounds->y1 < clip->y0) code1 |= 2; if (bounds->x1 > clip->x1) code1 |= 4; if (bounds->x1 < clip->x0) code1 |= 8; /* trivial accept: just return FALSE */ if ((code0 | code1) == 0) return FALSE; /* trivial reject: just return TRUE */ if ((code0 & code1) != 0) return TRUE; /* fix one of the OOB cases */ thiscode = code0 ? code0 : code1; /* off the bottom */ if (thiscode & 1) { x = bounds->x0 + (bounds->x1 - bounds->x0) * (clip->y1 - bounds->y0) / (bounds->y1 - bounds->y0); y = clip->y1; } /* off the top */ else if (thiscode & 2) { x = bounds->x0 + (bounds->x1 - bounds->x0) * (clip->y0 - bounds->y0) / (bounds->y1 - bounds->y0); y = clip->y0; } /* off the right */ else if (thiscode & 4) { y = bounds->y0 + (bounds->y1 - bounds->y0) * (clip->x1 - bounds->x0) / (bounds->x1 - bounds->x0); x = clip->x1; } /* off the left */ else { y = bounds->y0 + (bounds->y1 - bounds->y0) * (clip->x0 - bounds->x0) / (bounds->x1 - bounds->x0); x = clip->x0; } /* fix the appropriate coordinate */ if (thiscode == code0) { bounds->x0 = x; bounds->y0 = y; } else { bounds->x1 = x; bounds->y1 = y; } } } /*------------------------------------------------- render_clip_quad - clip a quad to a rectangle -------------------------------------------------*/ int render_clip_quad(render_bounds *bounds, const render_bounds *clip, render_quad_texuv *texcoords) { /* ensure our assumptions about the bounds are correct */ assert(bounds->x0 <= bounds->x1); assert(bounds->y0 <= bounds->y1); /* trivial reject */ if (bounds->y1 < clip->y0) return TRUE; if (bounds->y0 > clip->y1) return TRUE; if (bounds->x1 < clip->x0) return TRUE; if (bounds->x0 > clip->x1) return TRUE; /* clip top (x0,y0)-(x1,y1) */ if (bounds->y0 < clip->y0) { float frac = (clip->y0 - bounds->y0) / (bounds->y1 - bounds->y0); bounds->y0 = clip->y0; if (texcoords != NULL) { texcoords->tl.u += (texcoords->bl.u - texcoords->tl.u) * frac; texcoords->tl.v += (texcoords->bl.v - texcoords->tl.v) * frac; texcoords->tr.u += (texcoords->br.u - texcoords->tr.u) * frac; texcoords->tr.v += (texcoords->br.v - texcoords->tr.v) * frac; } } /* clip bottom (x3,y3)-(x2,y2) */ if (bounds->y1 > clip->y1) { float frac = (bounds->y1 - clip->y1) / (bounds->y1 - bounds->y0); bounds->y1 = clip->y1; if (texcoords != NULL) { texcoords->bl.u -= (texcoords->bl.u - texcoords->tl.u) * frac; texcoords->bl.v -= (texcoords->bl.v - texcoords->tl.v) * frac; texcoords->br.u -= (texcoords->br.u - texcoords->tr.u) * frac; texcoords->br.v -= (texcoords->br.v - texcoords->tr.v) * frac; } } /* clip left (x0,y0)-(x3,y3) */ if (bounds->x0 < clip->x0) { float frac = (clip->x0 - bounds->x0) / (bounds->x1 - bounds->x0); bounds->x0 = clip->x0; if (texcoords != NULL) { texcoords->tl.u += (texcoords->tr.u - texcoords->tl.u) * frac; texcoords->tl.v += (texcoords->tr.v - texcoords->tl.v) * frac; texcoords->bl.u += (texcoords->br.u - texcoords->bl.u) * frac; texcoords->bl.v += (texcoords->br.v - texcoords->bl.v) * frac; } } /* clip right (x1,y1)-(x2,y2) */ if (bounds->x1 > clip->x1) { float frac = (bounds->x1 - clip->x1) / (bounds->x1 - bounds->x0); bounds->x1 = clip->x1; if (texcoords != NULL) { texcoords->tr.u -= (texcoords->tr.u - texcoords->tl.u) * frac; texcoords->tr.v -= (texcoords->tr.v - texcoords->tl.v) * frac; texcoords->br.u -= (texcoords->br.u - texcoords->bl.u) * frac; texcoords->br.v -= (texcoords->br.v - texcoords->bl.v) * frac; } } return FALSE; } /*------------------------------------------------- render_line_to_quad - convert a line and a width to four points -------------------------------------------------*/ void render_line_to_quad(const render_bounds *bounds, float width, render_bounds *bounds0, render_bounds *bounds1) { render_bounds modbounds = *bounds; float unitx, unity; /* High-level logic -- due to math optimizations, this info is lost below. Imagine a thick line of width (w), drawn from (p0) to (p1), with a unit vector (u) indicating the direction from (p0) to (p1). B C +---------------- ... ------------------+ | ^ | | | | | | | * (p0) ------------> (w)| * (p1) | (u) | | | | | | v | +---------------- ... ------------------+ A D To convert this into a quad, we need to compute the four points A, B, C and D. Starting with point A. We first multiply the unit vector by 0.5w and then rotate the result 90 degrees. Thus, we have: A.x = p0.x + 0.5 * w * u.x * cos(90) - 0.5 * w * u.y * sin(90) A.y = p0.y + 0.5 * w * u.x * sin(90) + 0.5 * w * u.y * cos(90) Conveniently, sin(90) = 1, and cos(90) = 0, so this simplifies to: A.x = p0.x - 0.5 * w * u.y A.y = p0.y + 0.5 * w * u.x Working clockwise around the polygon, the same fallout happens all around as we rotate the unit vector by -90 (B), -90 (C), and 90 (D) degrees: B.x = p0.x + 0.5 * w * u.y B.y = p0.y - 0.5 * w * u.x C.x = p1.x - 0.5 * w * u.y C.y = p1.y + 0.5 * w * u.x D.x = p1.x + 0.5 * w * u.y D.y = p1.y - 0.5 * w * u.x */ /* we only care about the half-width */ width *= 0.5f; /* compute a vector from point 0 to point 1 */ unitx = modbounds.x1 - modbounds.x0; unity = modbounds.y1 - modbounds.y0; /* points just use a +1/+1 unit vector; this gives a nice diamond pattern */ if (unitx == 0 && unity == 0) { unitx = unity = 0.70710678f * width; modbounds.x0 -= 0.5f * unitx; modbounds.y0 -= 0.5f * unity; modbounds.x1 += 0.5f * unitx; modbounds.y1 += 0.5f * unity; } /* lines need to be divided by their length */ else { /* prescale unitx and unity by the half-width */ float invlength = width / sqrt(unitx * unitx + unity * unity); unitx *= invlength; unity *= invlength; } /* rotate the unit vector by 90 degrees and add to point 0 */ bounds0->x0 = modbounds.x0 - unity; bounds0->y0 = modbounds.y0 + unitx; /* rotate the unit vector by -90 degrees and add to point 0 */ bounds0->x1 = modbounds.x0 + unity; bounds0->y1 = modbounds.y0 - unitx; /* rotate the unit vector by 90 degrees and add to point 1 */ bounds1->x0 = modbounds.x1 - unity; bounds1->y0 = modbounds.y1 + unitx; /* rotate the unit vector by -09 degrees and add to point 1 */ bounds1->x1 = modbounds.x1 + unity; bounds1->y1 = modbounds.y1 - unitx; } /*------------------------------------------------- render_load_png - load a PNG file into a bitmap_t -------------------------------------------------*/ bitmap_t *render_load_png(const char *dirname, const char *filename, bitmap_t *alphadest, int *hasalpha) { bitmap_t *bitmap = NULL; file_error filerr; mame_file *file; png_info png; astring *fname; png_error result; /* open the file */ if (dirname == NULL) fname = astring_dupc(filename); else fname = astring_assemble_3(astring_alloc(), dirname, PATH_SEPARATOR, filename); filerr = mame_fopen(SEARCHPATH_ARTWORK, astring_c(fname), OPEN_FLAG_READ, &file); astring_free(fname); if (filerr != FILERR_NONE) return NULL; /* read the PNG data */ result = png_read_file(mame_core_file(file), &png); mame_fclose(file); if (result != PNGERR_NONE) return NULL; /* verify we can handle this PNG */ if (png.bit_depth > 8) { logerror("%s: Unsupported bit depth %d (8 bit max)\n", filename, png.bit_depth); png_free(&png); return NULL; } if (png.interlace_method != 0) { logerror("%s: Interlace unsupported\n", filename); png_free(&png); return NULL; } if (png.color_type != 0 && png.color_type != 3 && png.color_type != 2 && png.color_type != 6) { logerror("%s: Unsupported color type %d\n", filename, png.color_type); png_free(&png); return NULL; } /* if less than 8 bits, upsample */ png_expand_buffer_8bit(&png); /* non-alpha case */ if (alphadest == NULL) { bitmap = bitmap_alloc(png.width, png.height, BITMAP_FORMAT_ARGB32); if (bitmap != NULL) copy_png_to_bitmap(bitmap, &png, hasalpha); } /* alpha case */ else { if (png.width == alphadest->width && png.height == alphadest->height) { bitmap = alphadest; copy_png_alpha_to_bitmap(bitmap, &png, hasalpha); } } /* free PNG data */ png_free(&png); return bitmap; } /*------------------------------------------------- copy_png_to_bitmap - copy the PNG data to a bitmap -------------------------------------------------*/ static void copy_png_to_bitmap(bitmap_t *bitmap, const png_info *png, int *hasalpha) { UINT8 accumalpha = 0xff; UINT8 *src; int x, y; /* handle 8bpp palettized case */ if (png->color_type == 3) { /* loop over width/height */ src = png->image; for (y = 0; y < png->height; y++) for (x = 0; x < png->width; x++, src++) { /* determine alpha and expand to 32bpp */ UINT8 alpha = (*src < png->num_trans) ? png->trans[*src] : 0xff; accumalpha &= alpha; *BITMAP_ADDR32(bitmap, y, x) = MAKE_ARGB(alpha, png->palette[*src * 3], png->palette[*src * 3 + 1], png->palette[*src * 3 + 2]); } } /* handle 8bpp grayscale case */ else if (png->color_type == 0) { /* loop over width/height */ src = png->image; for (y = 0; y < png->height; y++) for (x = 0; x < png->width; x++, src++) *BITMAP_ADDR32(bitmap, y, x) = MAKE_ARGB(0xff, *src, *src, *src); } /* handle 32bpp non-alpha case */ else if (png->color_type == 2) { /* loop over width/height */ src = png->image; for (y = 0; y < png->height; y++) for (x = 0; x < png->width; x++, src += 3) *BITMAP_ADDR32(bitmap, y, x) = MAKE_ARGB(0xff, src[0], src[1], src[2]); } /* handle 32bpp alpha case */ else { /* loop over width/height */ src = png->image; for (y = 0; y < png->height; y++) for (x = 0; x < png->width; x++, src += 4) { accumalpha &= src[3]; *BITMAP_ADDR32(bitmap, y, x) = MAKE_ARGB(src[3], src[0], src[1], src[2]); } } /* set the hasalpha flag */ if (hasalpha != NULL) *hasalpha = (accumalpha != 0xff); } /*------------------------------------------------- copy_png_alpha_to_bitmap - copy the PNG data to the alpha channel of a bitmap -------------------------------------------------*/ static void copy_png_alpha_to_bitmap(bitmap_t *bitmap, const png_info *png, int *hasalpha) { UINT8 accumalpha = 0xff; UINT8 *src; int x, y; /* handle 8bpp palettized case */ if (png->color_type == 3) { /* loop over width/height */ src = png->image; for (y = 0; y < png->height; y++) for (x = 0; x < png->width; x++, src++) { rgb_t pixel = *BITMAP_ADDR32(bitmap, y, x); UINT8 alpha = compute_brightness(MAKE_RGB(png->palette[*src * 3], png->palette[*src * 3 + 1], png->palette[*src * 3 + 2])); accumalpha &= alpha; *BITMAP_ADDR32(bitmap, y, x) = MAKE_ARGB(alpha, RGB_RED(pixel), RGB_GREEN(pixel), RGB_BLUE(pixel)); } } /* handle 8bpp grayscale case */ else if (png->color_type == 0) { /* loop over width/height */ src = png->image; for (y = 0; y < png->height; y++) for (x = 0; x < png->width; x++, src++) { rgb_t pixel = *BITMAP_ADDR32(bitmap, y, x); accumalpha &= *src; *BITMAP_ADDR32(bitmap, y, x) = MAKE_ARGB(*src, RGB_RED(pixel), RGB_GREEN(pixel), RGB_BLUE(pixel)); } } /* handle 32bpp non-alpha case */ else if (png->color_type == 2) { /* loop over width/height */ src = png->image; for (y = 0; y < png->height; y++) for (x = 0; x < png->width; x++, src += 3) { rgb_t pixel = *BITMAP_ADDR32(bitmap, y, x); UINT8 alpha = compute_brightness(MAKE_RGB(src[0], src[1], src[2])); accumalpha &= alpha; *BITMAP_ADDR32(bitmap, y, x) = MAKE_ARGB(alpha, RGB_RED(pixel), RGB_GREEN(pixel), RGB_BLUE(pixel)); } } /* handle 32bpp alpha case */ else { /* loop over width/height */ src = png->image; for (y = 0; y < png->height; y++) for (x = 0; x < png->width; x++, src += 4) { rgb_t pixel = *BITMAP_ADDR32(bitmap, y, x); UINT8 alpha = compute_brightness(MAKE_RGB(src[0], src[1], src[2])); accumalpha &= alpha; *BITMAP_ADDR32(bitmap, y, x) = MAKE_ARGB(alpha, RGB_RED(pixel), RGB_GREEN(pixel), RGB_BLUE(pixel)); } } /* set the hasalpha flag */ if (hasalpha != NULL) *hasalpha = (accumalpha != 0xff); }