nuclear@18: #include <assert.h>
nuclear@18: #include "opengl.h"
nuclear@18: #include "shadow.h"
nuclear@18: #include "vmath/vmath.h"
nuclear@18: 
nuclear@19: bool shadow_pass;
nuclear@19: 
nuclear@18: static int tex_sz, prev_vp[4];
nuclear@18: static unsigned int fbo, depth_tex, rb_color;
nuclear@18: static Matrix4x4 shadow_mat;
nuclear@18: 
nuclear@18: bool init_shadow(int sz)
nuclear@18: {
nuclear@19: 	if(!glcaps.fbo || !glcaps.shadow) {
nuclear@19: 		return false;
nuclear@18: 	}
nuclear@18: 
nuclear@18: 	tex_sz = sz;
nuclear@19: 	printf("initializing shadow buffer (%dx%d)\n", tex_sz, tex_sz);
nuclear@18: 
nuclear@18: 	glGenFramebuffers(1, &fbo);
nuclear@18: 	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
nuclear@18: 
nuclear@18: 	glGenTextures(1, &depth_tex);
nuclear@18: 	glBindTexture(GL_TEXTURE_2D, depth_tex);
nuclear@19: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
nuclear@19: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
nuclear@18: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
nuclear@18: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
nuclear@18: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_R_TO_TEXTURE);
nuclear@18: 	glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT24, tex_sz, tex_sz, 0,
nuclear@18: 			GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, 0);
nuclear@18: 	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth_tex, 0);
nuclear@18: 
nuclear@18: 	assert(glGetError() == GL_NO_ERROR);
nuclear@18: 
nuclear@18: 	glDrawBuffer(GL_FALSE);
nuclear@18: 	glReadBuffer(GL_FALSE);
nuclear@18: 
nuclear@18: 	if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
nuclear@18: 		fprintf(stderr, "incomplete framebuffer\n");
nuclear@18: 		return false;
nuclear@18: 	}
nuclear@18: 
nuclear@18: 	glBindFramebuffer(GL_FRAMEBUFFER, 0);
nuclear@18: 	glDrawBuffer(GL_BACK);
nuclear@18: 	glReadBuffer(GL_BACK);
nuclear@18: 	assert(glGetError() == GL_NO_ERROR);
nuclear@18: 
nuclear@18: 	return true;
nuclear@18: }
nuclear@18: 
nuclear@18: void destroy_shadow()
nuclear@18: {
nuclear@18: 	glDeleteTextures(1, &depth_tex);
nuclear@18: 	glDeleteRenderbuffers(1, &rb_color);
nuclear@18: 	glDeleteFramebuffers(1, &fbo);
nuclear@18: }
nuclear@18: 
nuclear@18: void begin_shadow_pass(const Vector3 &lpos, const Vector3 &ltarg, float lfov)
nuclear@18: {
nuclear@19: 	shadow_pass = true;
nuclear@18: 
nuclear@18: 	glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT);
nuclear@18: 	glDisable(GL_LIGHTING);
nuclear@18: 	glColorMask(0, 0, 0, 0);
nuclear@18: 	glDepthMask(1);
nuclear@18: 
nuclear@19: 	Matrix4x4 viewmat;
nuclear@19: 	glGetFloatv(GL_MODELVIEW_MATRIX, viewmat[0]);
nuclear@19: 	viewmat.transpose();
nuclear@19: 
nuclear@19: 	Matrix4x4 lt_viewmat, lt_projmat;
nuclear@19: 	lt_projmat.set_perspective(DEG_TO_RAD(lfov) * 2.0, 1.0, 8.0, 50.0);
nuclear@19: 	lt_viewmat.set_lookat(lpos, ltarg, Vector3(0, 1, 0));
nuclear@19: 	shadow_mat = lt_projmat * lt_viewmat * viewmat.inverse();
nuclear@18: 
nuclear@18: 	glMatrixMode(GL_PROJECTION);
nuclear@18: 	glPushMatrix();
nuclear@19: 	glLoadTransposeMatrixf(lt_projmat[0]);
nuclear@19: 
nuclear@18: 	glMatrixMode(GL_MODELVIEW);
nuclear@18: 	glPushMatrix();
nuclear@19: 	glLoadTransposeMatrixf(lt_viewmat[0]);
nuclear@18: 
nuclear@18: 	glGetIntegerv(GL_VIEWPORT, prev_vp);
nuclear@18: 	glViewport(0, 0, tex_sz, tex_sz);
nuclear@18: 
nuclear@18: 	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
nuclear@19: 
nuclear@19: 	glPolygonOffset(2, 2);
nuclear@19: 	glEnable(GL_POLYGON_OFFSET_FILL);
nuclear@19: 
nuclear@19: 	glClear(GL_DEPTH_BUFFER_BIT);
nuclear@19: 	glUseProgram(0);
nuclear@18: }
nuclear@18: 
nuclear@18: 
nuclear@18: void end_shadow_pass()
nuclear@18: {
nuclear@19: 	shadow_pass = false;
nuclear@19: 
nuclear@18: 	glBindFramebuffer(GL_FRAMEBUFFER, 0);
nuclear@18: 
nuclear@18: 	glViewport(prev_vp[0], prev_vp[1], prev_vp[2], prev_vp[3]);
nuclear@18: 
nuclear@18: 	glMatrixMode(GL_PROJECTION);
nuclear@18: 	glPopMatrix();
nuclear@18: 	glMatrixMode(GL_MODELVIEW);
nuclear@18: 	glPopMatrix();
nuclear@18: 
nuclear@18: 	glPopAttrib();
nuclear@18: }
nuclear@18: 
nuclear@18: Matrix4x4 get_shadow_matrix()
nuclear@18: {
nuclear@18: 	return shadow_mat;
nuclear@19: 
nuclear@19: 	/*
nuclear@19: 	glMatrixMode(GL_MODELVIEW);
nuclear@19: 	glPushMatrix();
nuclear@19: 	glLoadIdentity();
nuclear@19: 	gluPerspective(lfov * 2.0, 1.0, 0.5, 50.0);
nuclear@19: 	gluLookAt(lpos.x, lpos.y, lpos.z, ltarg.x, ltarg.y, ltarg.z, 0, 1, 0);
nuclear@19: 
nuclear@19: 	float mat[16];
nuclear@19: 	glGetFloatv(GL_MODELVIEW_MATRIX, mat);
nuclear@19: 
nuclear@19: 	Matrix4x4 res;
nuclear@19: 	memcpy(res[0], mat, sizeof mat);
nuclear@19: 	res.transpose();
nuclear@19: 	return res;
nuclear@19: 	*/
nuclear@18: }
nuclear@18: 
nuclear@18: unsigned int get_shadow_tex()
nuclear@18: {
nuclear@18: 	return depth_tex;
nuclear@18: }