1 #include <GL/glew.h>

2 #include "demo.h"

3 #include "sdr.h"

4 #include "volray.h"

5

6 #define SZ 128

7

8 static Volume *vol;

9 static unsigned int sdr_mballs;

10 static unsigned int fbo;

11

12 bool init_demo()

13 {

14 if(!(sdr_mballs = create_program_load("sdr/demo.v.glsl", "sdr/demo.p.glsl"))) {

15 return false;

16 }

17

18 vol = new Volume;

19 vol->create(SZ, SZ, SZ);

20 volray_setvolume(vol);

21

22 glGenFramebuffers(1, &fbo);

23 glBindFramebuffer(GL_FRAMEBUFFER, fbo);

24 glFramebufferTexture3D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_3D,

25 vol->get_texture(), 0, 0);

26

27 unsigned int stat = glCheckFramebufferStatus(GL_FRAMEBUFFER);

28 if(stat != GL_FRAMEBUFFER_COMPLETE) {

29 printf("incomplete framebuffer: %u\n", stat);

30 delete vol;

31 return false;

32 }

33 glBindFramebuffer(GL_FRAMEBUFFER, 0);

34

35 return true;

36 }

37

38 void draw_demo()

39 {

40 if(volray_getvolume() != vol) {

41 return;

42 }

43

44 glPushAttrib(GL_VIEWPORT_BIT);

45 glViewport(0, 0, SZ, SZ);

46

47 glBindFramebuffer(GL_FRAMEBUFFER, fbo);

48 bind_program(sdr_mballs);

49

50 for(int i=0; i<SZ; i++) {

51 glFramebufferTexture3D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_3D,

52 vol->get_texture(), 0, i);

53

54 float z = (float)i / (float)SZ;

55

56 glBegin(GL_QUADS);

57 glTexCoord3f(0, 0, z);

58 glVertex2f(-1, -1);

59 glTexCoord3f(1, 0, z);

60 glVertex2f(1, -1);

61 glTexCoord3f(1, 1, z);

62 glVertex2f(1, 1);

63 glTexCoord3f(0, 1, z);

64 glVertex2f(-1, 1);

65 glEnd();

66 }

67

68 bind_program(0);

69 glBindFramebuffer(GL_FRAMEBUFFER, 0);

70

71 glPopAttrib();

72 }