#define __NR_GRADIENT_C__ /* * Pixel buffer rendering library * * Authors: * Lauris Kaplinski <lauris@kaplinski.com> * * This code is in public domain */ #include <libnr/nr-pixops.h> #include <libnr/nr-pixblock-pixel.h> #include <libnr/nr-blit.h> #include <libnr/nr-gradient.h> #define NRG_MASK (NR_GRADIENT_VECTOR_LENGTH - 1) #define NRG_2MASK ((long long) ((NR_GRADIENT_VECTOR_LENGTH << 1) - 1)) /* Radial */ static void nr_rgradient_render_block_symmetric(NRRenderer *r, NRPixBlock *pb, NRPixBlock *m); static void nr_rgradient_render_block_optimized(NRRenderer *r, NRPixBlock *pb, NRPixBlock *m); static void nr_rgradient_render_block_end(NRRenderer *r, NRPixBlock *pb, NRPixBlock *m); static void nr_rgradient_render_generic_symmetric(NRRGradientRenderer *rgr, NRPixBlock *pb); static void nr_rgradient_render_generic_optimized(NRRGradientRenderer *rgr, NRPixBlock *pb); NRRenderer * nr_rgradient_renderer_setup(NRRGradientRenderer *rgr, unsigned char const *cv, unsigned spread, NRMatrix const *gs2px, float cx, float cy, float fx, float fy, float r) { rgr->vector = cv; rgr->spread = spread; if (r < NR_EPSILON) { rgr->renderer.render = nr_rgradient_render_block_end; } else if (NR_DF_TEST_CLOSE(cx, fx, NR_EPSILON) && NR_DF_TEST_CLOSE(cy, fy, NR_EPSILON)) { rgr->renderer.render = nr_rgradient_render_block_symmetric; nr_matrix_invert(&rgr->px2gs, gs2px); rgr->px2gs.c[0] *= (NR_GRADIENT_VECTOR_LENGTH / r); rgr->px2gs.c[1] *= (NR_GRADIENT_VECTOR_LENGTH / r); rgr->px2gs.c[2] *= (NR_GRADIENT_VECTOR_LENGTH / r); rgr->px2gs.c[3] *= (NR_GRADIENT_VECTOR_LENGTH / r); rgr->px2gs.c[4] -= cx; rgr->px2gs.c[5] -= cy; rgr->px2gs.c[4] *= (NR_GRADIENT_VECTOR_LENGTH / r); rgr->px2gs.c[5] *= (NR_GRADIENT_VECTOR_LENGTH / r); rgr->cx = 0.0; rgr->cy = 0.0; rgr->fx = rgr->cx; rgr->fy = rgr->cy; rgr->r = 1.0; } else { rgr->renderer.render = nr_rgradient_render_block_optimized; NR::Coord const df = hypot(fx - cx, fy - cy); if (df >= r) { fx = cx + (fx - cx ) * r / (float) df; fy = cy + (fy - cy ) * r / (float) df; } NRMatrix n2gs; n2gs.c[0] = cx - fx; n2gs.c[1] = cy - fy; n2gs.c[2] = cy - fy; n2gs.c[3] = fx - cx; n2gs.c[4] = fx; n2gs.c[5] = fy; NRMatrix n2px; nr_matrix_multiply(&n2px, &n2gs, gs2px); nr_matrix_invert(&rgr->px2gs, &n2px); rgr->cx = 1.0; rgr->cy = 0.0; rgr->fx = 0.0; rgr->fy = 0.0; rgr->r = r / (float) hypot(fx - cx, fy - cy); rgr->C = 1.0F - rgr->r * rgr->r; /* INVARIANT: C < 0 */ rgr->C = MIN(rgr->C, -NR_EPSILON); } return (NRRenderer *) rgr; } static void nr_rgradient_render_block_symmetric(NRRenderer *r, NRPixBlock *pb, NRPixBlock *m) { NRRGradientRenderer *rgr = (NRRGradientRenderer *) r; nr_rgradient_render_generic_symmetric(rgr, pb); } static void nr_rgradient_render_block_optimized(NRRenderer *r, NRPixBlock *pb, NRPixBlock *m) { NRRGradientRenderer *rgr = (NRRGradientRenderer *) r; nr_rgradient_render_generic_optimized(rgr, pb); } static void nr_rgradient_render_block_end(NRRenderer *r, NRPixBlock *pb, NRPixBlock *m) { unsigned char const *c = ((NRRGradientRenderer *) r)->vector + 4 * (NR_GRADIENT_VECTOR_LENGTH - 1); nr_blit_pixblock_mask_rgba32(pb, m, (c[0] << 24) | (c[1] << 16) | (c[2] << 8) | c[3]); } /* * The archetype is following * * gx gy - pixel coordinates * Px Py - coordinates, where Fx Fy - gx gy line intersects with circle * * (1) (gx - fx) * (Py - fy) = (gy - fy) * (Px - fx) * (2) (Px - cx) * (Px - cx) + (Py - cy) * (Py - cy) = r * r * * (3) Py = (Px - fx) * (gy - fy) / (gx - fx) + fy * (4) (gy - fy) / (gx - fx) = D * (5) Py = D * Px - D * fx + fy * * (6) D * fx - fy + cy = N * (7) Px * Px - 2 * Px * cx + cx * cx + (D * Px) * (D * Px) - 2 * (D * Px) * N + N * N = r * r * (8) (D * D + 1) * (Px * Px) - 2 * (cx + D * N) * Px + cx * cx + N * N = r * r * * (9) A = D * D + 1 * (10) B = -2 * (cx + D * N) * (11) C = cx * cx + N * N - r * r * * (12) Px = (-B +- SQRT(B * B - 4 * A * C)) / 2 * A */ static void nr_rgradient_render_generic_symmetric(NRRGradientRenderer *rgr, NRPixBlock *pb) { NR::Coord const dx = rgr->px2gs.c[0]; NR::Coord const dy = rgr->px2gs.c[1]; if (pb->mode == NR_PIXBLOCK_MODE_R8G8B8A8P) { for (int y = pb->area.y0; y < pb->area.y1; y++) { unsigned char *d = NR_PIXBLOCK_PX(pb) + (y - pb->area.y0) * pb->rs; NR::Coord gx = rgr->px2gs.c[0] * pb->area.x0 + rgr->px2gs.c[2] * y + rgr->px2gs.c[4]; NR::Coord gy = rgr->px2gs.c[1] * pb->area.x0 + rgr->px2gs.c[3] * y + rgr->px2gs.c[5]; for (int x = pb->area.x0; x < pb->area.x1; x++) { NR::Coord const pos = sqrt(((gx*gx) + (gy*gy))); int idx; if (rgr->spread == NR_GRADIENT_SPREAD_REFLECT) { idx = (int) ((long long) pos & NRG_2MASK); if (idx > NRG_MASK) idx = NRG_2MASK - idx; } else if (rgr->spread == NR_GRADIENT_SPREAD_REPEAT) { idx = (int) ((long long) pos & NRG_MASK); } else { idx = (int) CLAMP(pos, 0, (double) NRG_MASK); } unsigned char const *s = rgr->vector + 4 * idx; d[0] = NR_COMPOSENPP_1111(s[0], s[3], d[0]); d[1] = NR_COMPOSENPP_1111(s[1], s[3], d[1]); d[2] = NR_COMPOSENPP_1111(s[2], s[3], d[2]); d[3] = NR_COMPOSEA_111(s[3], d[3]); d += 4; gx += dx; gy += dy; } } } else if (pb->mode == NR_PIXBLOCK_MODE_R8G8B8A8N) { for (int y = pb->area.y0; y < pb->area.y1; y++) { unsigned char *d = NR_PIXBLOCK_PX(pb) + (y - pb->area.y0) * pb->rs; NR::Coord gx = rgr->px2gs.c[0] * pb->area.x0 + rgr->px2gs.c[2] * y + rgr->px2gs.c[4]; NR::Coord gy = rgr->px2gs.c[1] * pb->area.x0 + rgr->px2gs.c[3] * y + rgr->px2gs.c[5]; for (int x = pb->area.x0; x < pb->area.x1; x++) { NR::Coord const pos = sqrt(((gx*gx) + (gy*gy))); int idx; if (rgr->spread == NR_GRADIENT_SPREAD_REFLECT) { idx = (int) ((long long) pos & NRG_2MASK); if (idx > NRG_MASK) idx = NRG_2MASK - idx; } else if (rgr->spread == NR_GRADIENT_SPREAD_REPEAT) { idx = (int) ((long long) pos & NRG_MASK); } else { idx = (int) CLAMP(pos, 0, (double) NRG_MASK); } unsigned char const *s = rgr->vector + 4 * idx; if (s[3] == 255) { d[0] = s[0]; d[1] = s[1]; d[2] = s[2]; d[3] = 255; } else if (s[3] != 0) { unsigned ca = NR_COMPOSEA_112(s[3], d[3]); d[0] = NR_COMPOSENNN_111121(s[0], s[3], d[0], d[3], ca); d[1] = NR_COMPOSENNN_111121(s[1], s[3], d[1], d[3], ca); d[2] = NR_COMPOSENNN_111121(s[2], s[3], d[2], d[3], ca); d[3] = NR_NORMALIZE_21(ca); } d += 4; gx += dx; gy += dy; } } } else { NRPixBlock spb; nr_pixblock_setup_extern(&spb, NR_PIXBLOCK_MODE_R8G8B8A8N, 0, 0, NR_GRADIENT_VECTOR_LENGTH, 1, (unsigned char *) rgr->vector, 4 * NR_GRADIENT_VECTOR_LENGTH, 0, 0); int const bpp = ( pb->mode == NR_PIXBLOCK_MODE_A8 ? 1 : pb->mode == NR_PIXBLOCK_MODE_R8G8B8 ? 3 : 4 ); for (int y = pb->area.y0; y < pb->area.y1; y++) { unsigned char *d = NR_PIXBLOCK_PX(pb) + (y - pb->area.y0) * pb->rs; NR::Coord gx = rgr->px2gs.c[0] * pb->area.x0 + rgr->px2gs.c[2] * y + rgr->px2gs.c[4]; NR::Coord gy = rgr->px2gs.c[1] * pb->area.x0 + rgr->px2gs.c[3] * y + rgr->px2gs.c[5]; for (int x = pb->area.x0; x < pb->area.x1; x++) { NR::Coord const pos = sqrt(((gx*gx) + (gy*gy))); int idx; if (rgr->spread == NR_GRADIENT_SPREAD_REFLECT) { idx = (int) ((long long) pos & NRG_2MASK); if (idx > NRG_MASK) idx = NRG_2MASK - idx; } else if (rgr->spread == NR_GRADIENT_SPREAD_REPEAT) { idx = (int) ((long long) pos & NRG_MASK); } else { idx = (int) CLAMP(pos, 0, (double) NRG_MASK); } unsigned char const *s = rgr->vector + 4 * idx; nr_compose_pixblock_pixblock_pixel(pb, d, &spb, s); d += bpp; gx += dx; gy += dy; } } nr_pixblock_release(&spb); } } static void nr_rgradient_render_generic_optimized(NRRGradientRenderer *rgr, NRPixBlock *pb) { int const x0 = pb->area.x0; int const y0 = pb->area.y0; int const x1 = pb->area.x1; int const y1 = pb->area.y1; int const rs = pb->rs; NRPixBlock spb; nr_pixblock_setup_extern(&spb, NR_PIXBLOCK_MODE_R8G8B8A8N, 0, 0, NR_GRADIENT_VECTOR_LENGTH, 1, (unsigned char *) rgr->vector, 4 * NR_GRADIENT_VECTOR_LENGTH, 0, 0); int const bpp = ( pb->mode == NR_PIXBLOCK_MODE_A8 ? 1 : pb->mode == NR_PIXBLOCK_MODE_R8G8B8 ? 3 : 4 ); for (int y = y0; y < y1; y++) { unsigned char *d = NR_PIXBLOCK_PX(pb) + (y - y0) * rs; NR::Coord gx = rgr->px2gs.c[0] * x0 + rgr->px2gs.c[2] * y + rgr->px2gs.c[4]; NR::Coord gy = rgr->px2gs.c[1] * x0 + rgr->px2gs.c[3] * y + rgr->px2gs.c[5]; NR::Coord const dx = rgr->px2gs.c[0]; NR::Coord const dy = rgr->px2gs.c[1]; for (int x = x0; x < x1; x++) { NR::Coord const gx2 = gx * gx; NR::Coord const gxy2 = gx2 + gy * gy; NR::Coord const qgx2_4 = gx2 - rgr->C * gxy2; /* INVARIANT: qgx2_4 >= 0.0 */ /* qgx2_4 = MAX(qgx2_4, 0.0); */ NR::Coord const pxgx = gx + sqrt(qgx2_4); /* We can safely divide by 0 here */ /* If we are sure pxgx cannot be -0 */ NR::Coord const pos = gxy2 / pxgx * NR_GRADIENT_VECTOR_LENGTH; int idx; if (pos < (1U << 31)) { if (rgr->spread == NR_GRADIENT_SPREAD_REFLECT) { idx = (int) ((long long) pos & NRG_2MASK); if (idx > NRG_MASK) idx = NRG_2MASK - idx; } else if (rgr->spread == NR_GRADIENT_SPREAD_REPEAT) { idx = (int) ((long long) pos & NRG_MASK); } else { idx = (int) CLAMP(pos, 0, (double) (NR_GRADIENT_VECTOR_LENGTH - 1)); } } else { idx = NR_GRADIENT_VECTOR_LENGTH - 1; } unsigned char const *s = rgr->vector + 4 * idx; nr_compose_pixblock_pixblock_pixel(pb, d, &spb, s); d += bpp; gx += dx; gy += dy; } } nr_pixblock_release(&spb); } /* Local Variables: mode:c++ c-file-style:"stroustrup" c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) indent-tabs-mode:nil fill-column:99 End: */ // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :