Actual source code: cmap.c
petsc-3.9.4 2018-09-11
1: #include <petscsys.h>
2: #include <petscdraw.h>
4: /*
5: Set up a color map, using uniform separation in hue space.
6: Map entries are Red, Green, Blue.
7: Values are "gamma" corrected.
8: */
10: /*
11: Gamma is a monitor dependent value. The value here is an
12: approximate that gives somewhat better results than Gamma = 1.
13: */
14: static PetscReal Gamma = 2.0;
16: PetscErrorCode PetscDrawUtilitySetGamma(PetscReal g)
17: {
19: Gamma = g;
20: return(0);
21: }
23: PETSC_STATIC_INLINE double PetscHlsHelper(double m1,double m2,double h)
24: {
25: while (h > 1.0) h -= 1.0;
26: while (h < 0.0) h += 1.0;
27: if (h < 1/6.0) return m1 + (m2-m1)*h*6;
28: if (h < 1/2.0) return m2;
29: if (h < 2/3.0) return m1 + (m2-m1)*(2/3.0-h)*6;
30: return m1;
31: }
33: PETSC_STATIC_INLINE void PetscHlsToRgb(double h,double l,double s,double *r,double *g,double *b)
34: {
35: if (s > 0.0) {
36: double m2 = l <= 0.5 ? l * (1.0+s) : l+s-(l*s);
37: double m1 = 2*l - m2;
38: *r = PetscHlsHelper(m1,m2,h+1/3.);
39: *g = PetscHlsHelper(m1,m2,h);
40: *b = PetscHlsHelper(m1,m2,h-1/3.);
41: } else {
42: /* ignore hue */
43: *r = *g = *b = l;
44: }
45: }
47: PETSC_STATIC_INLINE void PetscGammaCorrect(double *r,double *g,double *b)
48: {
49: PetscReal igamma = 1/Gamma;
50: *r = (double)PetscPowReal((PetscReal)*r,igamma);
51: *g = (double)PetscPowReal((PetscReal)*g,igamma);
52: *b = (double)PetscPowReal((PetscReal)*b,igamma);
53: }
55: static PetscErrorCode PetscDrawCmap_Hue(int mapsize, unsigned char R[],unsigned char G[],unsigned char B[])
56: {
57: int i;
58: double maxhue = 212.0/360,lightness = 0.5,saturation = 1.0;
61: for (i=0; i<mapsize; i++) {
62: double hue = maxhue*(double)i/(mapsize-1),r,g,b;
63: PetscHlsToRgb(hue,lightness,saturation,&r,&g,&b);
64: PetscGammaCorrect(&r,&g,&b);
65: R[i] = (unsigned char)(255*PetscMin(r,1.0));
66: G[i] = (unsigned char)(255*PetscMin(g,1.0));
67: B[i] = (unsigned char)(255*PetscMin(b,1.0));
68: }
69: return(0);
70: }
72: static PetscErrorCode PetscDrawCmap_Gray(int mapsize,unsigned char R[],unsigned char G[],unsigned char B[])
73: {
74: int i;
76: for (i=0; i<mapsize; i++) R[i] = G[i] = B[i] = (unsigned char)((255.0*i)/(mapsize-1));
77: return(0);
78: }
80: static PetscErrorCode PetscDrawCmap_Jet(int mapsize,unsigned char R[],unsigned char G[],unsigned char B[])
81: {
82: int i;
83: const double knots[] = {0, 1/8., 3/8., 5/8., 7/8., 1};
86: for (i=0; i<mapsize; i++) {
87: double u = (double)i/(mapsize-1);
88: double m, r=0, g=0, b=0; int k = 0;
89: while(k < 4 && u > knots[k+1]) k++;
90: m = (u-knots[k])/(knots[k+1]-knots[k]);
91: switch(k) {
92: case 0: r = 0; g = 0; b = (m+1)/2; break;
93: case 1: r = 0; g = m; b = 1; break;
94: case 2: r = m; g = 1; b = 1-m; break;
95: case 3: r = 1; g = 1-m; b = 0; break;
96: case 4: r = 1-m/2; g = 0; b = 0; break;
97: }
98: R[i] = (unsigned char)(255*PetscMin(r,1.0));
99: G[i] = (unsigned char)(255*PetscMin(g,1.0));
100: B[i] = (unsigned char)(255*PetscMin(b,1.0));
101: }
102: return(0);
103: }
105: static PetscErrorCode PetscDrawCmap_Hot(int mapsize,unsigned char R[],unsigned char G[],unsigned char B[])
106: {
107: int i;
108: const double knots[] = {0, 3/8., 3/4., 1};
111: for (i=0; i<mapsize; i++) {
112: double u = (double)i/(mapsize-1);
113: double m, r=0, g=0, b=0; int k = 0;
114: while(k < 2 && u > knots[k+1]) k++;
115: m = (u-knots[k])/(knots[k+1]-knots[k]);
116: switch(k) {
117: case 0: r = m; g = 0; b = 0; break;
118: case 1: r = 1; g = m; b = 0; break;
119: case 2: r = 1; g = 1; b = m; break;
120: }
121: R[i] = (unsigned char)(255*PetscMin(r,1.0));
122: G[i] = (unsigned char)(255*PetscMin(g,1.0));
123: B[i] = (unsigned char)(255*PetscMin(b,1.0));
124: }
125: return(0);
126: }
128: static PetscErrorCode PetscDrawCmap_Bone(int mapsize,unsigned char R[],unsigned char G[],unsigned char B[])
129: {
130: int i;
132: (void)PetscDrawCmap_Hot(mapsize,R,G,B);
133: for (i=0; i<mapsize; i++) {
134: double u = (double)i/(mapsize-1);
135: double r = (7*u + B[i]/255.0)/8;
136: double g = (7*u + G[i]/255.0)/8;
137: double b = (7*u + R[i]/255.0)/8;
138: R[i] = (unsigned char)(255*PetscMin(r,1.0));
139: G[i] = (unsigned char)(255*PetscMin(g,1.0));
140: B[i] = (unsigned char)(255*PetscMin(b,1.0));
141: }
142: return(0);
143: }
145: #include "../src/sys/classes/draw/utils/cmap/coolwarm.h"
146: #include "../src/sys/classes/draw/utils/cmap/parula.h"
147: #include "../src/sys/classes/draw/utils/cmap/viridis.h"
148: #include "../src/sys/classes/draw/utils/cmap/plasma.h"
149: #include "../src/sys/classes/draw/utils/cmap/inferno.h"
150: #include "../src/sys/classes/draw/utils/cmap/magma.h"
152: static struct {
153: const char *name;
154: const unsigned char (*data)[3];
155: PetscErrorCode (*cmap)(int,unsigned char[],unsigned char[],unsigned char[]);
156: } PetscDrawCmapTable[] = {
157: {"hue", NULL, PetscDrawCmap_Hue }, /* varying hue with constant lightness and saturation */
158: {"gray", NULL, PetscDrawCmap_Gray}, /* black to white with shades of gray */
159: {"bone", NULL, PetscDrawCmap_Bone}, /* black to white with gray-blue shades */
160: {"jet", NULL, PetscDrawCmap_Jet }, /* rainbow-like colormap from NCSA, University of Illinois */
161: {"hot", NULL, PetscDrawCmap_Hot }, /* black-body radiation */
162: {"coolwarm", PetscDrawCmap_coolwarm, NULL}, /* ParaView default (Cool To Warm with Diverging interpolation) */
163: {"parula", PetscDrawCmap_parula, NULL}, /* MATLAB (default since R2014b) */
164: {"viridis", PetscDrawCmap_viridis, NULL}, /* matplotlib 1.5 (default since 2.0) */
165: {"plasma", PetscDrawCmap_plasma, NULL}, /* matplotlib 1.5 */
166: {"inferno", PetscDrawCmap_inferno, NULL}, /* matplotlib 1.5 */
167: {"magma", PetscDrawCmap_magma, NULL}, /* matplotlib 1.5 */
168: };
170: PetscErrorCode PetscDrawUtilitySetCmap(const char colormap[],int mapsize,unsigned char R[],unsigned char G[],unsigned char B[])
171: {
172: int i,j;
173: const char *cmap_name_list[sizeof(PetscDrawCmapTable)/sizeof(PetscDrawCmapTable[0])];
174: PetscInt id = 0, count = (PetscInt)(sizeof(cmap_name_list)/sizeof(char*));
175: PetscBool reverse = PETSC_FALSE, brighten = PETSC_FALSE;
176: PetscReal beta = 0;
177: PetscErrorCode ierr;
180: for (i=0; i<count; i++) cmap_name_list[i] = PetscDrawCmapTable[i].name;
181: if (colormap && colormap[0]) {
182: PetscBool match = PETSC_FALSE;
183: for (id=0; !match && id<count; id++) {PetscStrcasecmp(colormap,cmap_name_list[id],&match);}
184: if (!match) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Colormap '%s' not found",colormap);
185: }
186: PetscOptionsGetEList(NULL,NULL,"-draw_cmap",cmap_name_list,count,&id,NULL);
187: PetscOptionsGetBool(NULL,NULL,"-draw_cmap_reverse",&reverse,NULL);
188: PetscOptionsGetReal(NULL,NULL,"-draw_cmap_brighten",&beta,&brighten);
189: if (brighten && (beta <= (PetscReal)-1 || beta >= (PetscReal)+1)) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"brighten parameter %g must be in the range (-1,1)",(double)beta);
191: if (PetscDrawCmapTable[id].cmap) {
192: PetscDrawCmapTable[id].cmap(mapsize,R,G,B);
193: } else {
194: const unsigned char (*rgb)[3] = PetscDrawCmapTable[id].data;
195: if (mapsize != 256-PETSC_DRAW_BASIC_COLORS) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_SUP,"Colormap '%s' with size %d not supported",cmap_name_list[id],mapsize);
196: for (i=0; i<mapsize; i++) {R[i] = rgb[i][0]; G[i] = rgb[i][1]; B[i] = rgb[i][2];}
197: }
199: if (reverse) {
200: i = 0; j = mapsize-1;
201: while(i < j) {
202: #define SWAP(a,i,j) do { unsigned char t = a[i]; a[i] = a[j]; a[j] = t; } while (0)
203: SWAP(R,i,j);
204: SWAP(G,i,j);
205: SWAP(B,i,j);
206: #undef SWAP
207: i++; j--;
208: }
209: }
211: if (brighten) {
212: PetscReal gamma = (beta > 0.0) ? (1 - beta) : (1 / (1 + beta));
213: for (i=0; i<mapsize; i++) {
214: PetscReal r = PetscPowReal((PetscReal)R[i]/255,gamma);
215: PetscReal g = PetscPowReal((PetscReal)G[i]/255,gamma);
216: PetscReal b = PetscPowReal((PetscReal)B[i]/255,gamma);
217: R[i] = (unsigned char)(255*PetscMin(r,(PetscReal)1.0));
218: G[i] = (unsigned char)(255*PetscMin(g,(PetscReal)1.0));
219: B[i] = (unsigned char)(255*PetscMin(b,(PetscReal)1.0));
220: }
221: }
222: return(0);
223: }