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

   1 #define GPH_NAMESPACE
   2 #include <assert.h>
   3 #include "opengl.h"
   4 #include "shadow.h"
   5
   6 #undef DBG_USE_VMATH
   7
   8 #ifdef DBG_USE_VMATH
   9 #include "vmath/vmath.h"
  10 #else
  11 #include "gmath/gmath.h"
  12 #endif
  13
  14
  15 bool shadow_pass;
  16
  17 static int tex_sz, prev_vp[4];
  18 static unsigned int fbo, depth_tex, rb_color;
  19 static gph::Mat4 shadow_mat;
  20
  21 bool init_shadow(int sz)
  22 {
  23         tex_sz = sz;
  24         printf("initializing shadow buffer (%dx%d)\n", tex_sz, tex_sz);
  25
  26         glGenFramebuffers(1, &fbo);
  27         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
  28
  29         const float border_color[] = {1, 1, 1, 1};
  30
  31         glGenTextures(1, &depth_tex);
  32         glBindTexture(GL_TEXTURE_2D, depth_tex);
  33         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
  34         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
  35         glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, border_color);
  36         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  37         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  38         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_R_TO_TEXTURE);
  39         glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT24, tex_sz, tex_sz, 0,
  40                         GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, 0);
  41         glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth_tex, 0);
  42
  43         assert(glGetError() == GL_NO_ERROR);
  44
  45         glDrawBuffer(GL_FALSE);
  46         glReadBuffer(GL_FALSE);
  47
  48         if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
  49                 fprintf(stderr, "incomplete framebuffer\n");
  50                 return false;
  51         }
  52
  53         glBindFramebuffer(GL_FRAMEBUFFER, 0);
  54         glDrawBuffer(GL_BACK);
  55         glReadBuffer(GL_BACK);
  56         assert(glGetError() == GL_NO_ERROR);
  57
  58         return true;
  59 }
  60
  61 void destroy_shadow()
  62 {
  63         glDeleteTextures(1, &depth_tex);
  64         glDeleteRenderbuffers(1, &rb_color);
  65         glDeleteFramebuffers(1, &fbo);
  66 }
  67
  68 void begin_shadow_pass(const gph::Vec3 &lpos, const gph::Vec3 &ltarg, float lfov, float znear, float zfar)
  69 {
  70         shadow_pass = true;
  71
  72         glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT);
  73         glDisable(GL_LIGHTING);
  74         glColorMask(0, 0, 0, 0);
  75         glDepthMask(1);
  76
  77 #ifdef DBG_USE_VMATH
  78         Matrix4x4 viewmat;
  79         glGetFloatv(GL_MODELVIEW_MATRIX, viewmat[0]);
  80         viewmat.transpose();
  81
  82         Matrix4x4 lt_viewmat, lt_projmat;
  83         lt_projmat.set_perspective(DEG_TO_RAD(lfov) * 2.0, 1.0, znear, zfar);
  84         lt_viewmat.set_lookat(Vector3(lpos.x, lpos.y, lpos.z), Vector3(ltarg.x, ltarg.y, ltarg.z), Vector3(0, 1, 0));
  85         Matrix4x4 smat = lt_projmat * lt_viewmat * viewmat.inverse();
  86         smat.transpose();
  87
  88         memcpy(shadow_mat[0], smat[0], 16 * sizeof(float));
  89
  90         glMatrixMode(GL_PROJECTION);
  91         glPushMatrix();
  92         glLoadTransposeMatrixf(lt_projmat[0]);
  93
  94         glMatrixMode(GL_MODELVIEW);
  95         glPushMatrix();
  96         glLoadTransposeMatrixf(lt_viewmat[0]);
  97 #else
  98         gph::Mat4 viewmat;
  99         glGetFloatv(GL_MODELVIEW_MATRIX, viewmat[0]);
 100
 101         gph::Mat4 lt_viewmat, lt_projmat;
 102         lt_projmat.perspective(gph::deg_to_rad(lfov) * 2.0, 1.0, znear, zfar);
 103         lt_viewmat.inv_lookat(lpos, ltarg, gph::Vec3(0, 1, 0));
 104         shadow_mat = lt_projmat * lt_viewmat * viewmat.inverse();
 105         //shadow_mat = viewmat.inverse() * lt_viewmat * lt_projmat;
 106         shadow_mat.print();
 107
 108         glMatrixMode(GL_PROJECTION);
 109         glPushMatrix();
 110         glLoadMatrixf(lt_projmat[0]);
 111
 112         glMatrixMode(GL_MODELVIEW);
 113         glPushMatrix();
 114         glLoadMatrixf(lt_viewmat[0]);
 115 #endif
 116
 117         glGetIntegerv(GL_VIEWPORT, prev_vp);
 118         glViewport(0, 0, tex_sz, tex_sz);
 119
 120         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 121
 122         glPolygonOffset(2, 2);
 123         glEnable(GL_POLYGON_OFFSET_FILL);
 124
 125         glClear(GL_DEPTH_BUFFER_BIT);
 126         glUseProgram(0);
 127 }
 128
 129
 130 void end_shadow_pass()
 131 {
 132         shadow_pass = false;
 133
 134         glBindFramebuffer(GL_FRAMEBUFFER, 0);
 135
 136         glViewport(prev_vp[0], prev_vp[1], prev_vp[2], prev_vp[3]);
 137
 138         glMatrixMode(GL_PROJECTION);
 139         glPopMatrix();
 140         glMatrixMode(GL_MODELVIEW);
 141         glPopMatrix();
 142
 143         glPopAttrib();
 144 }
 145
 146 gph::Mat4 get_shadow_matrix()
 147 {
 148         return shadow_mat;
 149 }
 150
 151 unsigned int get_shadow_tex()
 152 {
 153         return depth_tex;
 154 }