git.mutantstargoat.com Git - antikythera/blob - src/shadow.cc

   1 #define GPH_NAMESPACE
   2 #include <assert.h>
   3 #include "opengl.h"
   4 #include "shadow.h"
   5 #include "vmath/vmath.h"
   6
   7
   8 bool shadow_pass;
   9
  10 static int tex_sz, prev_vp[4];
  11 static unsigned int fbo, depth_tex, rb_color;
  12 static gph::Mat4 shadow_mat;
  13
  14 bool init_shadow(int sz)
  15 {
  16         tex_sz = sz;
  17         printf("initializing shadow buffer (%dx%d)\n", tex_sz, tex_sz);
  18
  19         glGenFramebuffers(1, &fbo);
  20         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
  21
  22         const float border_color[] = {1, 1, 1, 1};
  23
  24         glGenTextures(1, &depth_tex);
  25         glBindTexture(GL_TEXTURE_2D, depth_tex);
  26         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
  27         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
  28         glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, border_color);
  29         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  30         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  31         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_R_TO_TEXTURE);
  32         glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT24, tex_sz, tex_sz, 0,
  33                         GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, 0);
  34         glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth_tex, 0);
  35
  36         assert(glGetError() == GL_NO_ERROR);
  37
  38         glDrawBuffer(GL_FALSE);
  39         glReadBuffer(GL_FALSE);
  40
  41         if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
  42                 fprintf(stderr, "incomplete framebuffer\n");
  43                 return false;
  44         }
  45
  46         glBindFramebuffer(GL_FRAMEBUFFER, 0);
  47         glDrawBuffer(GL_BACK);
  48         glReadBuffer(GL_BACK);
  49         assert(glGetError() == GL_NO_ERROR);
  50
  51         return true;
  52 }
  53
  54 void destroy_shadow()
  55 {
  56         glDeleteTextures(1, &depth_tex);
  57         glDeleteRenderbuffers(1, &rb_color);
  58         glDeleteFramebuffers(1, &fbo);
  59 }
  60
  61 void begin_shadow_pass(const gph::Vec3 &lpos, const gph::Vec3 &ltarg, float lfov, float znear, float zfar)
  62 {
  63         shadow_pass = true;
  64
  65         glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT);
  66         glDisable(GL_LIGHTING);
  67         glColorMask(0, 0, 0, 0);
  68         glDepthMask(1);
  69
  70         Matrix4x4 viewmat;
  71         glGetFloatv(GL_MODELVIEW_MATRIX, viewmat[0]);
  72         viewmat.transpose();
  73
  74         Matrix4x4 lt_viewmat, lt_projmat;
  75         lt_projmat.set_perspective(DEG_TO_RAD(lfov) * 2.0, 1.0, znear, zfar);
  76         lt_viewmat.set_lookat(Vector3(lpos.x, lpos.y, lpos.z), Vector3(ltarg.x, ltarg.y, ltarg.z), Vector3(0, 1, 0));
  77         Matrix4x4 smat = lt_projmat * lt_viewmat * viewmat.inverse();
  78         smat.transpose();
  79
  80         memcpy(shadow_mat[0], smat[0], 16 * sizeof(float));
  81
  82         glMatrixMode(GL_PROJECTION);
  83         glPushMatrix();
  84         glLoadTransposeMatrixf(lt_projmat[0]);
  85
  86         glMatrixMode(GL_MODELVIEW);
  87         glPushMatrix();
  88         glLoadTransposeMatrixf(lt_viewmat[0]);
  89
  90
  91         /*gph::Mat4 viewmat;
  92         glGetFloatv(GL_MODELVIEW_MATRIX, viewmat[0]);
  93
  94         gph::Mat4 lt_viewmat, lt_projmat;
  95         lt_projmat.perspective(deg_to_rad(lfov) * 2.0, 1.0, znear, zfar);
  96         lt_viewmat.inv_lookat(lpos, ltarg, gph::Vec3(0, 1, 0));
  97         shadow_mat = lt_projmat * lt_viewmat * viewmat.inverse();
  98         //shadow_mat = viewmat.inverse() * lt_viewmat * lt_projmat;
  99         shadow_mat.print();
 100
 101         glMatrixMode(GL_PROJECTION);
 102         glPushMatrix();
 103         glLoadMatrixf(lt_projmat[0]);
 104
 105         glMatrixMode(GL_MODELVIEW);
 106         glPushMatrix();
 107         glLoadMatrixf(lt_viewmat[0]);
 108         */
 109
 110         glGetIntegerv(GL_VIEWPORT, prev_vp);
 111         glViewport(0, 0, tex_sz, tex_sz);
 112
 113         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 114
 115         glPolygonOffset(2, 2);
 116         glEnable(GL_POLYGON_OFFSET_FILL);
 117
 118         glClear(GL_DEPTH_BUFFER_BIT);
 119         glUseProgram(0);
 120 }
 121
 122
 123 void end_shadow_pass()
 124 {
 125         shadow_pass = false;
 126
 127         glBindFramebuffer(GL_FRAMEBUFFER, 0);
 128
 129         glViewport(prev_vp[0], prev_vp[1], prev_vp[2], prev_vp[3]);
 130
 131         glMatrixMode(GL_PROJECTION);
 132         glPopMatrix();
 133         glMatrixMode(GL_MODELVIEW);
 134         glPopMatrix();
 135
 136         glPopAttrib();
 137 }
 138
 139 gph::Mat4 get_shadow_matrix()
 140 {
 141         return shadow_mat;
 142 }
 143
 144 unsigned int get_shadow_tex()
 145 {
 146         return depth_tex;
 147 }