progs/egl/openvg/trivial/arc.c

   1 #include "eglcommon.h"
   2
   3 #include <VG/openvg.h>
   4 #include <math.h>
   5
   6 const VGfloat clear_color[4] = {1.0, 1.0, 1.0, 1.0};
   7 const VGfloat color[4] = {1.0, 1.0, 1.0, 0.5};
   8
   9 VGPath vgPath;
  10
  11 static void ellipse(VGPath vgPath, VGfloat rx, VGfloat ry, VGfloat angle)
  12 {
  13     static const VGubyte cmd[] =
  14     { VG_MOVE_TO_ABS, VG_SCCWARC_TO_REL, VG_SCCWARC_TO_REL, VG_CLOSE_PATH };
  15
  16     VGfloat val[12];
  17     VGfloat c = cos(angle) * rx;
  18     VGfloat s = sin(angle) * rx;
  19
  20     val[0] = c;
  21     val[1] = s;
  22     val[2] = rx;
  23     val[3] = ry;
  24     val[4] = angle;
  25     val[5] = -2.0f * c;
  26     val[6] = -2.0f * s;
  27     val[7] = rx;
  28     val[8] = ry;
  29     val[9] = angle;
  30     val[10] = 2.0f * c;
  31     val[11] = 2.0f * s;
  32
  33     vgClearPath(vgPath, VG_PATH_CAPABILITY_ALL);
  34     vgAppendPathData(vgPath, sizeof(cmd), cmd, val);
  35     vgDrawPath(vgPath, VG_FILL_PATH | VG_STROKE_PATH);
  36 }
  37
  38 static void
  39 init(void)
  40 {
  41     VGPaint vgPaint;
  42
  43     vgSetfv(VG_CLEAR_COLOR, 4, clear_color);
  44     vgPath = vgCreatePath(VG_PATH_FORMAT_STANDARD,
  45                           VG_PATH_DATATYPE_F, 1.0f, 0.0f, 0, 0,
  46                           VG_PATH_CAPABILITY_ALL);
  47
  48     vgPaint = vgCreatePaint();
  49     vgSetParameteri(vgPaint, VG_PAINT_TYPE, VG_PAINT_TYPE_COLOR);
  50     vgSetColor(vgPaint, 0x00ff00ff);
  51     vgSetPaint(vgPaint, VG_FILL_PATH);
  52
  53     vgSeti(VG_RENDERING_QUALITY, VG_RENDERING_QUALITY_NONANTIALIASED);
  54     vgSeti(VG_BLEND_MODE, VG_BLEND_SRC_OVER);
  55     vgSetf(VG_STROKE_LINE_WIDTH, 2.0f);
  56     vgSeti(VG_STROKE_CAP_STYLE, VG_CAP_SQUARE);
  57     vgSeti(VG_STROKE_JOIN_STYLE, VG_JOIN_MITER);
  58     vgSetf(VG_STROKE_MITER_LIMIT, 4.0f);
  59     vgSeti(VG_MATRIX_MODE, VG_MATRIX_PATH_USER_TO_SURFACE);
  60 }
  61
  62 /* new window size or exposure */
  63 static void
  64 reshape(int w, int h)
  65 {
  66 }
  67
  68 static void
  69 draw(void)
  70 {
  71     vgClear(0, 0, window_width(), window_height());
  72
  73 #if 0
  74     vgLoadIdentity();
  75     vgTranslate(40.0f, 24.0f);
  76     vgScale(0.61804f, 0.61804f);
  77     vgShear(-1.0f, 0.0f);
  78     vgDrawPath(vgPath, VG_FILL_PATH | VG_STROKE_PATH);
  79 #else
  80
  81     /* row 1, col 1: Identity transform. */
  82
  83     vgLoadIdentity();
  84     vgTranslate(8.0f, 8.0f);
  85     ellipse(vgPath, 4.0f, 4.0f, 0.0f);
  86
  87     /* row 1, col 2: 10^3 horizontal squeeze. */
  88
  89     vgLoadIdentity();
  90     vgTranslate(24.0f, 8.0f);
  91     vgScale(1.0e-3f, 1.0f);
  92     ellipse(vgPath, 4.0e3f, 4.0f, 0.0f);
  93
  94     /* row 1, col 3: 10^6 horizontal squeeze. */
  95
  96     vgLoadIdentity();
  97     vgTranslate(40.0f, 8.0f);
  98     vgScale(1.0e-6f, 1.0f);
  99     ellipse(vgPath, 4.0e6f, 4.0f, 0.0f);
 100
 101     /* row 1, col 4: 10^9 horizontal squeeze. */
 102
 103     vgLoadIdentity();
 104     vgTranslate(56.0f, 8.0f);
 105     vgScale(1.0e-9f, 1.0f);
 106     ellipse(vgPath, 4.0e9f, 4.0f, 0.0f);
 107
 108     /* row 2, col 1: 10^3 vertical squeeze. */
 109
 110     vgLoadIdentity();
 111     vgTranslate(8.0f, 24.0f);
 112     vgScale(1.0f, 1.0e-3f);
 113     ellipse(vgPath, 4.0f, 4.0e3f, 0.0f);
 114
 115     /* row 2, col 2: Shear 0. */
 116
 117     vgLoadIdentity();
 118     vgTranslate(24.0f, 24.0f);
 119     vgShear(0.0f, 0.0f);
 120     ellipse(vgPath, 4.0f, 4.0f, 0.0f);
 121
 122     /* row 2, col 3: Horizontal shear -1. */
 123
 124     vgLoadIdentity();
 125     vgTranslate(40.0f, 24.0f);
 126     vgScale(0.61804f, 0.61804f);
 127     vgShear(-1.0f, 0.0f);
 128     ellipse(vgPath, 10.47213f, 4.0f, 31.717f);
 129 #endif
 130     vgFlush();
 131 }
 132
 133
 134 int main(int argc, char **argv)
 135 {
 136     set_window_size(64, 64);
 137    return run(argc, argv, init, reshape,
 138               draw, 0);
 139 }