progs/egl/openvg/trivial/lingrad.c

   1 #include "eglcommon.h"
   2
   3 #include <VG/openvg.h>
   4
   5 #include <stdio.h>
   6 #include <string.h>
   7
   8 static const VGfloat white_color[4] = {1.0, 1.0, 1.0, 1.0};
   9
  10 static VGPath path;
  11 static VGPaint fill;
  12
  13 VGColorRampSpreadMode spread = VG_COLOR_RAMP_SPREAD_PAD;
  14
  15 static void
  16 init(void)
  17 {
  18    static const VGubyte sqrCmds[5] = {VG_MOVE_TO_ABS, VG_HLINE_TO_ABS, VG_VLINE_TO_ABS, VG_HLINE_TO_ABS, VG_CLOSE_PATH};
  19    static const VGfloat sqrCoords[5]   = {0.0f, 0.0f, 400.0f, 400.0f, 0.0f};
  20
  21    VGfloat rampStop[] = {0.00f, 1.0f, 1.0f, 1.0f, 1.0f,
  22                          0.33f, 1.0f, 0.0f, 0.0f, 1.0f,
  23                          0.66f, 0.0f, 1.0f, 0.0f, 1.0f,
  24                          1.00f, 0.0f, 0.0f,  1.0f, 1.0f};
  25    VGfloat linearGradient[4] = {100.0f, 100.0f, 300.0f, 300.0f};
  26
  27    path = vgCreatePath(VG_PATH_FORMAT_STANDARD, VG_PATH_DATATYPE_F, 1, 0, 0, 0,
  28                        VG_PATH_CAPABILITY_APPEND_TO);
  29    vgAppendPathData(path, 5, sqrCmds, sqrCoords);
  30
  31    fill = vgCreatePaint();
  32    vgSetPaint(fill, VG_FILL_PATH);
  33
  34    vgSetParameteri(fill, VG_PAINT_TYPE, VG_PAINT_TYPE_LINEAR_GRADIENT);
  35    vgSetParameteri(fill, VG_PAINT_COLOR_RAMP_SPREAD_MODE, spread);
  36    vgSetParameterfv(fill, VG_PAINT_LINEAR_GRADIENT, 4, linearGradient);
  37    vgSetParameterfv(fill, VG_PAINT_COLOR_RAMP_STOPS, 20, rampStop);
  38
  39    vgSetfv(VG_CLEAR_COLOR, 4, white_color);
  40 }
  41
  42 /* new window size or exposure */
  43 static void
  44 reshape(int w, int h)
  45 {
  46    vgLoadIdentity();
  47 }
  48
  49 static void
  50 draw(void)
  51 {
  52    vgClear(0, 0, window_width(), window_height());
  53
  54    vgDrawPath(path, VG_FILL_PATH);
  55
  56    vgFlush();
  57 }
  58
  59
  60 int main(int argc, char **argv)
  61 {
  62    if (argc > 1) {
  63       const char *arg = argv[1];
  64       if (!strcmp("-pad", arg))
  65          spread = VG_COLOR_RAMP_SPREAD_PAD;
  66       else if (!strcmp("-repeat", arg))
  67          spread = VG_COLOR_RAMP_SPREAD_REPEAT;
  68       else if (!strcmp("-reflect", arg))
  69          spread = VG_COLOR_RAMP_SPREAD_REFLECT;
  70    }
  71
  72    switch(spread) {
  73    case VG_COLOR_RAMP_SPREAD_PAD:
  74       printf("Using spread mode: pad\n");
  75       break;
  76    case VG_COLOR_RAMP_SPREAD_REPEAT:
  77       printf("Using spread mode: repeat\n");
  78       break;
  79    case VG_COLOR_RAMP_SPREAD_REFLECT:
  80       printf("Using spread mode: reflect\n");
  81    }
  82
  83    set_window_size(400, 400);
  84
  85    return run(argc, argv, init, reshape,
  86               draw, 0);
  87 }