Actual source code: cmap.c
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: {
18: Gamma = g;
19: return 0;
20: }
22: static inline double PetscHlsHelper(double m1,double m2,double h)
23: {
24: while (h > 1.0) h -= 1.0;
25: while (h < 0.0) h += 1.0;
26: if (h < 1/6.0) return m1 + (m2-m1)*h*6;
27: if (h < 1/2.0) return m2;
28: if (h < 2/3.0) return m1 + (m2-m1)*(2/3.0-h)*6;
29: return m1;
30: }
32: static inline void PetscHlsToRgb(double h,double l,double s,double *r,double *g,double *b)
33: {
34: if (s > 0.0) {
35: double m2 = l <= 0.5 ? l * (1.0+s) : l+s-(l*s);
36: double m1 = 2*l - m2;
37: *r = PetscHlsHelper(m1,m2,h+1/3.);
38: *g = PetscHlsHelper(m1,m2,h);
39: *b = PetscHlsHelper(m1,m2,h-1/3.);
40: } else {
41: /* ignore hue */
42: *r = *g = *b = l;
43: }
44: }
46: static inline void PetscGammaCorrect(double *r,double *g,double *b)
47: {
48: PetscReal igamma = 1/Gamma;
49: *r = (double)PetscPowReal((PetscReal)*r,igamma);
50: *g = (double)PetscPowReal((PetscReal)*g,igamma);
51: *b = (double)PetscPowReal((PetscReal)*b,igamma);
52: }
54: static PetscErrorCode PetscDrawCmap_Hue(int mapsize, unsigned char R[],unsigned char G[],unsigned char B[])
55: {
56: int i;
57: double maxhue = 212.0/360,lightness = 0.5,saturation = 1.0;
59: for (i=0; i<mapsize; i++) {
60: double hue = maxhue*(double)i/(mapsize-1),r,g,b;
61: PetscHlsToRgb(hue,lightness,saturation,&r,&g,&b);
62: PetscGammaCorrect(&r,&g,&b);
63: R[i] = (unsigned char)(255*PetscMin(r,1.0));
64: G[i] = (unsigned char)(255*PetscMin(g,1.0));
65: B[i] = (unsigned char)(255*PetscMin(b,1.0));
66: }
67: return 0;
68: }
70: static PetscErrorCode PetscDrawCmap_Gray(int mapsize,unsigned char R[],unsigned char G[],unsigned char B[])
71: {
72: int i;
73: for (i=0; i<mapsize; i++) R[i] = G[i] = B[i] = (unsigned char)((255.0*i)/(mapsize-1));
74: return 0;
75: }
77: static PetscErrorCode PetscDrawCmap_Jet(int mapsize,unsigned char R[],unsigned char G[],unsigned char B[])
78: {
79: int i;
80: const double knots[] = {0, 1/8., 3/8., 5/8., 7/8., 1};
82: for (i=0; i<mapsize; i++) {
83: double u = (double)i/(mapsize-1);
84: double m, r=0, g=0, b=0; int k = 0;
85: while (k < 4 && u > knots[k+1]) k++;
86: m = (u-knots[k])/(knots[k+1]-knots[k]);
87: switch(k) {
88: case 0: r = 0; g = 0; b = (m+1)/2; break;
89: case 1: r = 0; g = m; b = 1; break;
90: case 2: r = m; g = 1; b = 1-m; break;
91: case 3: r = 1; g = 1-m; b = 0; break;
92: case 4: r = 1-m/2; g = 0; b = 0; break;
93: }
94: R[i] = (unsigned char)(255*PetscMin(r,1.0));
95: G[i] = (unsigned char)(255*PetscMin(g,1.0));
96: B[i] = (unsigned char)(255*PetscMin(b,1.0));
97: }
98: return 0;
99: }
101: static PetscErrorCode PetscDrawCmap_Hot(int mapsize,unsigned char R[],unsigned char G[],unsigned char B[])
102: {
103: int i;
104: const double knots[] = {0, 3/8., 3/4., 1};
106: for (i=0; i<mapsize; i++) {
107: double u = (double)i/(mapsize-1);
108: double m, r=0, g=0, b=0; int k = 0;
109: while (k < 2 && u > knots[k+1]) k++;
110: m = (u-knots[k])/(knots[k+1]-knots[k]);
111: switch(k) {
112: case 0: r = m; g = 0; b = 0; break;
113: case 1: r = 1; g = m; b = 0; break;
114: case 2: r = 1; g = 1; b = m; break;
115: }
116: R[i] = (unsigned char)(255*PetscMin(r,1.0));
117: G[i] = (unsigned char)(255*PetscMin(g,1.0));
118: B[i] = (unsigned char)(255*PetscMin(b,1.0));
119: }
120: return 0;
121: }
123: static PetscErrorCode PetscDrawCmap_Bone(int mapsize,unsigned char R[],unsigned char G[],unsigned char B[])
124: {
125: int i;
126: (void)PetscDrawCmap_Hot(mapsize,R,G,B);
127: for (i=0; i<mapsize; i++) {
128: double u = (double)i/(mapsize-1);
129: double r = (7*u + B[i]/255.0)/8;
130: double g = (7*u + G[i]/255.0)/8;
131: double b = (7*u + R[i]/255.0)/8;
132: R[i] = (unsigned char)(255*PetscMin(r,1.0));
133: G[i] = (unsigned char)(255*PetscMin(g,1.0));
134: B[i] = (unsigned char)(255*PetscMin(b,1.0));
135: }
136: return 0;
137: }
139: #include "../src/sys/classes/draw/utils/cmap/coolwarm.h"
140: #include "../src/sys/classes/draw/utils/cmap/parula.h"
141: #include "../src/sys/classes/draw/utils/cmap/viridis.h"
142: #include "../src/sys/classes/draw/utils/cmap/plasma.h"
143: #include "../src/sys/classes/draw/utils/cmap/inferno.h"
144: #include "../src/sys/classes/draw/utils/cmap/magma.h"
146: static struct {
147: const char *name;
148: const unsigned char (*data)[3];
149: PetscErrorCode (*cmap)(int,unsigned char[],unsigned char[],unsigned char[]);
150: } PetscDrawCmapTable[] = {
151: {"hue", NULL, PetscDrawCmap_Hue }, /* varying hue with constant lightness and saturation */
152: {"gray", NULL, PetscDrawCmap_Gray}, /* black to white with shades of gray */
153: {"bone", NULL, PetscDrawCmap_Bone}, /* black to white with gray-blue shades */
154: {"jet", NULL, PetscDrawCmap_Jet }, /* rainbow-like colormap from NCSA, University of Illinois */
155: {"hot", NULL, PetscDrawCmap_Hot }, /* black-body radiation */
156: {"coolwarm", PetscDrawCmap_coolwarm, NULL}, /* ParaView default (Cool To Warm with Diverging interpolation) */
157: {"parula", PetscDrawCmap_parula, NULL}, /* MATLAB (default since R2014b) */
158: {"viridis", PetscDrawCmap_viridis, NULL}, /* matplotlib 1.5 (default since 2.0) */
159: {"plasma", PetscDrawCmap_plasma, NULL}, /* matplotlib 1.5 */
160: {"inferno", PetscDrawCmap_inferno, NULL}, /* matplotlib 1.5 */
161: {"magma", PetscDrawCmap_magma, NULL}, /* matplotlib 1.5 */
162: };
164: PetscErrorCode PetscDrawUtilitySetCmap(const char colormap[],int mapsize,unsigned char R[],unsigned char G[],unsigned char B[])
165: {
166: int i,j;
167: const char *cmap_name_list[sizeof(PetscDrawCmapTable)/sizeof(PetscDrawCmapTable[0])];
168: PetscInt id = 0, count = (PetscInt)(sizeof(cmap_name_list)/sizeof(char*));
169: PetscBool reverse = PETSC_FALSE, brighten = PETSC_FALSE;
170: PetscReal beta = 0;
172: for (i=0; i<count; i++) cmap_name_list[i] = PetscDrawCmapTable[i].name;
173: if (colormap && colormap[0]) {
174: PetscBool match = PETSC_FALSE;
175: for (id=0; !match && id<count; id++) PetscStrcasecmp(colormap,cmap_name_list[id],&match);
177: }
178: PetscOptionsGetEList(NULL,NULL,"-draw_cmap",cmap_name_list,count,&id,NULL);
179: PetscOptionsGetBool(NULL,NULL,"-draw_cmap_reverse",&reverse,NULL);
180: PetscOptionsGetReal(NULL,NULL,"-draw_cmap_brighten",&beta,&brighten);
183: if (PetscDrawCmapTable[id].cmap) {
184: PetscDrawCmapTable[id].cmap(mapsize,R,G,B);
185: } else {
186: const unsigned char (*rgb)[3] = PetscDrawCmapTable[id].data;
188: for (i=0; i<mapsize; i++) {R[i] = rgb[i][0]; G[i] = rgb[i][1]; B[i] = rgb[i][2];}
189: }
191: if (reverse) {
192: i = 0; j = mapsize-1;
193: while (i < j) {
194: #define SWAP(a,i,j) do { unsigned char t = a[i]; a[i] = a[j]; a[j] = t; } while (0)
195: SWAP(R,i,j);
196: SWAP(G,i,j);
197: SWAP(B,i,j);
198: #undef SWAP
199: i++; j--;
200: }
201: }
203: if (brighten) {
204: PetscReal gamma = (beta > 0.0) ? (1 - beta) : (1 / (1 + beta));
205: for (i=0; i<mapsize; i++) {
206: PetscReal r = PetscPowReal((PetscReal)R[i]/255,gamma);
207: PetscReal g = PetscPowReal((PetscReal)G[i]/255,gamma);
208: PetscReal b = PetscPowReal((PetscReal)B[i]/255,gamma);
209: R[i] = (unsigned char)(255*PetscMin(r,(PetscReal)1.0));
210: G[i] = (unsigned char)(255*PetscMin(g,(PetscReal)1.0));
211: B[i] = (unsigned char)(255*PetscMin(b,(PetscReal)1.0));
212: }
213: }
214: return 0;
215: }