nuclear@12: /*
nuclear@12: glviewvol is an OpenGL 3D volume data viewer
nuclear@12: Copyright (C) 2014  John Tsiombikas <nuclear@member.fsf.org>
nuclear@12: 
nuclear@12: This program is free software: you can redistribute it and/or modify
nuclear@12: it under the terms of the GNU General Public License as published by
nuclear@12: the Free Software Foundation, either version 3 of the License, or
nuclear@12: (at your option) any later version.
nuclear@12: 
nuclear@12: This program is distributed in the hope that it will be useful,
nuclear@12: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@12: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@12: GNU General Public License for more details.
nuclear@12: 
nuclear@12: You should have received a copy of the GNU General Public License
nuclear@12: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@12: */
nuclear@4: #include <stdio.h>
nuclear@0: #include "opengl.h"
nuclear@0: #include "rend_fast.h"
nuclear@4: #include "sdr.h"
nuclear@4: 
nuclear@10: #define DEF_PROXY_COUNT	512
nuclear@8: #define XFER_MAP_SZ		512
nuclear@4: 
nuclear@4: static unsigned int sdr;
nuclear@4: static bool have_tex_float;
nuclear@0: 
nuclear@0: RendererFast::RendererFast()
nuclear@0: {
nuclear@4: 	vol_tex = xfer_tex = 0;
nuclear@4: 	vol_tex_valid = xfer_tex_valid = false;
nuclear@10: 	proxy_count = DEF_PROXY_COUNT;
nuclear@8: 	vbo_proxy_count = 0;
nuclear@0: }
nuclear@0: 
nuclear@0: bool RendererFast::init()
nuclear@0: {
nuclear@4: 	if(!sdr) {
nuclear@4: 		if(!(sdr = create_program_load("sdr/fast.v.glsl", "sdr/fast.p.glsl"))) {
nuclear@4: 			return false;
nuclear@4: 		}
nuclear@4: 		have_tex_float = GLEW_ARB_texture_float;
nuclear@4: 	}
nuclear@4: 
nuclear@0: 	glGenTextures(1, &vol_tex);
nuclear@0: 	glBindTexture(GL_TEXTURE_3D, vol_tex);
nuclear@0: 	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
nuclear@0: 	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
nuclear@8: 	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
nuclear@8: 	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
nuclear@8: 	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
nuclear@0: 
nuclear@4: 	glGenTextures(1, &xfer_tex);
nuclear@4: 	glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@4: 	glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
nuclear@4: 	glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
nuclear@8: 	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
nuclear@6: 	glTexImage1D(GL_TEXTURE_1D, 0, have_tex_float ? GL_RGBA16F : GL_RGBA, XFER_MAP_SZ, 0, GL_RGB, GL_FLOAT, 0);
nuclear@4: 
nuclear@8: 	glGenBuffers(1, &vbo);
nuclear@0: 	return true;
nuclear@0: }
nuclear@0: 
nuclear@0: void RendererFast::destroy()
nuclear@0: {
nuclear@0: 	glDeleteTextures(1, &vol_tex);
nuclear@4: 	glDeleteTextures(1, &xfer_tex);
nuclear@8: 	glDeleteBuffers(1, &vbo);
nuclear@4: }
nuclear@4: 
nuclear@4: void RendererFast::set_volume(Volume *vol)
nuclear@4: {
nuclear@4: 	vol_tex_valid = false;
nuclear@4: 	Renderer::set_volume(vol);
nuclear@4: }
nuclear@4: 
nuclear@8: void RendererFast::set_proxy_count(int n)
nuclear@8: {
nuclear@8: 	proxy_count = n;
nuclear@8: }
nuclear@8: 
nuclear@8: int RendererFast::get_proxy_count() const
nuclear@8: {
nuclear@8: 	return proxy_count;
nuclear@8: }
nuclear@8: 
nuclear@0: void RendererFast::update(unsigned int msec)
nuclear@0: {
nuclear@0: 	if(!vol) return;
nuclear@0: 
nuclear@0: 	// make sure the 3D volume texture is up to date
nuclear@0: 	if(!vol_tex_valid) {
nuclear@0: 		int xsz, ysz, zsz;
nuclear@0: 
nuclear@0: 		if((xsz = vol->num_samples(0)) > 0) {
nuclear@0: 			ysz = vol->num_samples(1);
nuclear@0: 			zsz = vol->num_samples(2);
nuclear@0: 		} else {
nuclear@0: 			xsz = ysz = zsz = 256;
nuclear@0: 		}
nuclear@0: 
nuclear@4: 		printf("updating 3D texture data (%dx%dx%d) ... ", xsz, ysz, zsz);
nuclear@4: 		fflush(stdout);
nuclear@4: 
nuclear@0: 		int int_fmt = GLEW_ARB_texture_float ? GL_RGBA16F_ARB : GL_RGBA;
nuclear@0: 
nuclear@0: 		glBindTexture(GL_TEXTURE_3D, vol_tex);
nuclear@0: 		glTexImage3D(GL_TEXTURE_3D, 0, int_fmt, xsz, ysz, zsz, 0, GL_RGBA, GL_FLOAT, 0);
nuclear@0: 
nuclear@0: 		float *slice = new float[xsz * ysz * 4];
nuclear@0: 
nuclear@0: 		for(int i=0; i<zsz; i++) {
nuclear@4: 			float z = (float)i;
nuclear@0: 
nuclear@9: #pragma omp parallel for schedule(dynamic)
nuclear@0: 			for(int j=0; j<ysz; j++) {
nuclear@4: 				float y = (float)j;
nuclear@9: 
nuclear@9: 				float *pptr = slice + (j * xsz) * 4;
nuclear@0: 				for(int k=0; k<xsz; k++) {
nuclear@4: 					float x = (float)k;
nuclear@0: 
nuclear@0: 					// value in alpha channel
nuclear@0: 					pptr[3] = vol->valuef(x, y, z);
nuclear@0: 					// normal in rgb
nuclear@0: 					vol->normalf(pptr, x, y, z);
nuclear@0: 					// shift normal to the [0,1] range in case we don't have tex_float
nuclear@0: 					pptr[0] = pptr[0] * 0.5 + 0.5;
nuclear@0: 					pptr[1] = pptr[1] * 0.5 + 0.5;
nuclear@0: 					pptr[2] = pptr[2] * 0.5 + 0.5;
nuclear@4: 
nuclear@4: 					pptr += 4;
nuclear@0: 				}
nuclear@0: 			}
nuclear@0: 
nuclear@0: 			glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, i, xsz, ysz, 1, GL_RGBA, GL_FLOAT, slice);
nuclear@0: 		}
nuclear@0: 
nuclear@4: 		printf("done\n");
nuclear@4: 
nuclear@0: 		delete [] slice;
nuclear@0: 
nuclear@0: 		vol_tex_valid = true;
nuclear@0: 	}
nuclear@4: 
nuclear@6: 	if(1) {//if(!xfer_tex_valid) {
nuclear@6: 		float pixels[XFER_MAP_SZ * 4];
nuclear@4: 		float *pptr = pixels;
nuclear@4: 
nuclear@4: 		for(int i=0; i<XFER_MAP_SZ; i++) {
nuclear@4: 			float x = (float)i / (float)(XFER_MAP_SZ - 1);
nuclear@5: 
nuclear@6: 			if(xfer) {
nuclear@6: 				xfer->map(x, pptr);
nuclear@7: 				pptr[3] = std::max(pptr[0], std::max(pptr[1], pptr[2]));
nuclear@6: 			} else {
nuclear@6: 				pptr[0] = pptr[1] = pptr[2] = pptr[3] = x;
nuclear@6: 			}
nuclear@6: 			pptr += 4;
nuclear@4: 		}
nuclear@4: 
nuclear@4: 		glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@6: 		glTexSubImage1D(GL_TEXTURE_1D, 0, 0, XFER_MAP_SZ, GL_RGBA, GL_FLOAT, pixels);
nuclear@4: 
nuclear@4: 		xfer_tex_valid = true;
nuclear@4: 	}
nuclear@8: 
nuclear@8: 	// make sure the proxy object is up to date
nuclear@8: 	if(proxy_count != vbo_proxy_count) {
nuclear@8: 		static const float pat[][3] = {{-1, -1}, {1, -1}, {1, 1}, {-1, 1}};
nuclear@8: 
nuclear@8: 		int nverts = proxy_count * 4;
nuclear@8: 		float *verts = new float[nverts * 3];
nuclear@8: 		float *vptr = verts;
nuclear@8: 
nuclear@8: 		for(int i=0; i<proxy_count; i++) {
nuclear@8: 			float z = 2.0 * (float)i / (float)(proxy_count - 1) - 1.0;
nuclear@8: 
nuclear@8: 			for(int j=0; j<4; j++) {
nuclear@8: 				*vptr++ = pat[j][0];
nuclear@8: 				*vptr++ = pat[j][1];
nuclear@8: 				*vptr++ = z;
nuclear@8: 			}
nuclear@8: 		}
nuclear@8: 
nuclear@8: 		glBindBuffer(GL_ARRAY_BUFFER, vbo);
nuclear@8: 		glBufferData(GL_ARRAY_BUFFER, nverts * 3 * sizeof(float), verts, GL_STATIC_DRAW);
nuclear@8: 		glBindBuffer(GL_ARRAY_BUFFER, 0);
nuclear@8: 
nuclear@8: 		delete [] verts;
nuclear@8: 		vbo_proxy_count = proxy_count;
nuclear@8: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: void RendererFast::render() const
nuclear@0: {
nuclear@0: 	if(!vol) return;
nuclear@0: 
nuclear@0: 	glClear(GL_COLOR_BUFFER_BIT);
nuclear@0: 
nuclear@4: 	glUseProgram(sdr);
nuclear@4: 
nuclear@4: 	glActiveTexture(GL_TEXTURE0);
nuclear@0: 	glBindTexture(GL_TEXTURE_3D, vol_tex);
nuclear@4: 	glActiveTexture(GL_TEXTURE1);
nuclear@4: 	glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@4: 
nuclear@4: 	set_uniform_int(sdr, "vol_tex", 0);
nuclear@4: 	set_uniform_int(sdr, "xfer_tex", 1);
nuclear@10: 	set_uniform_float(sdr, "zscale", zscale);
nuclear@4: 
nuclear@8: 	glEnable(GL_BLEND);
nuclear@8: 	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
nuclear@8: 
nuclear@8: 	glBindBuffer(GL_ARRAY_BUFFER, vbo);
nuclear@8: 	glVertexPointer(3, GL_FLOAT, 0, 0);
nuclear@8: 	glBindBuffer(GL_ARRAY_BUFFER, 0);
nuclear@8: 
nuclear@8: 	glEnableClientState(GL_VERTEX_ARRAY);
nuclear@8: 	glDrawArrays(GL_QUADS, 0, vbo_proxy_count * 4);
nuclear@8: 	glDisableClientState(GL_VERTEX_ARRAY);
nuclear@8: 
nuclear@8: 	glDisable(GL_BLEND);
nuclear@0: 
nuclear@4: 	glUseProgram(0);
nuclear@0: }