nuclear@4: #include <stdio.h>
nuclear@0: #include "opengl.h"
nuclear@0: #include "rend_fast.h"
nuclear@4: #include "sdr.h"
nuclear@4: 
nuclear@5: static inline float smoothstep(float a, float b, float x);
nuclear@5: 
nuclear@4: #define XFER_MAP_SZ		1024
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@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@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@4: 	glTexImage1D(GL_TEXTURE_1D, 0, have_tex_float ? GL_RGB16F : GL_RGB, XFER_MAP_SZ, 0, GL_RGB, GL_FLOAT, 0);
nuclear@4: 
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@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@4: Curve &RendererFast::transfer_curve(int color)
nuclear@4: {
nuclear@4: 	xfer_tex_valid = false;
nuclear@4: 	return Renderer::transfer_curve(color);
nuclear@0: }
nuclear@0: 
nuclear@5: void RendererFast::set_simple_transfer(float low, float high)
nuclear@5: {
nuclear@5: 	xfer_tex_valid = false;
nuclear@5: 	Renderer::set_simple_transfer(low, high);
nuclear@5: }
nuclear@5: 
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: 			float *pptr = slice;
nuclear@0: 
nuclear@0: 			for(int j=0; j<ysz; j++) {
nuclear@4: 				float y = (float)j;
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@4: 	if(!xfer_tex_valid) {
nuclear@4: 		float pixels[XFER_MAP_SZ * 3];
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@5: 			// TODO make 0.1 a tweakable parameter
nuclear@5: 			float val = smoothstep(xfer_low - 0.1, xfer_low + 0.1, x);
nuclear@5: 			val *= 1.0 - smoothstep(xfer_high - 0.1, xfer_high + 0.1, x);
nuclear@5: 			*pptr++ = val;
nuclear@5: 			*pptr++ = val;
nuclear@5: 			*pptr++ = val;
nuclear@5: 			/*
nuclear@4: 			*pptr++ = xfer[0].value(x);
nuclear@4: 			*pptr++ = xfer[1].value(x);
nuclear@4: 			*pptr++ = xfer[2].value(x);
nuclear@5: 			*/
nuclear@4: 		}
nuclear@4: 
nuclear@4: 		glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@4: 		glTexSubImage1D(GL_TEXTURE_1D, 0, 0, XFER_MAP_SZ, GL_RGB, GL_FLOAT, pixels);
nuclear@4: 
nuclear@4: 		xfer_tex_valid = true;
nuclear@4: 	}
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@0: 	glMatrixMode(GL_PROJECTION);
nuclear@0: 	glPushMatrix();
nuclear@0: 	glLoadIdentity();
nuclear@0: 
nuclear@0: 	glMatrixMode(GL_MODELVIEW);
nuclear@0: 	glPushMatrix();
nuclear@0: 	glLoadIdentity();
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@4: 
nuclear@0: 	glBegin(GL_QUADS);
nuclear@4: 	glTexCoord3f(0, 0, 0.5); glVertex2f(-1, -1);
nuclear@4: 	glTexCoord3f(1, 0, 0.5); glVertex2f(1, -1);
nuclear@4: 	glTexCoord3f(1, 1, 0.5); glVertex2f(1, 1);
nuclear@4: 	glTexCoord3f(0, 1, 0.5); glVertex2f(-1, 1);
nuclear@0: 	glEnd();
nuclear@0: 
nuclear@4: 	glUseProgram(0);
nuclear@4: 
nuclear@0: 	glMatrixMode(GL_PROJECTION);
nuclear@0: 	glPopMatrix();
nuclear@0: 	glMatrixMode(GL_MODELVIEW);
nuclear@0: 	glPopMatrix();
nuclear@0: }
nuclear@5: 
nuclear@5: static inline float smoothstep(float a, float b, float x)
nuclear@5: {
nuclear@5: 	if(x < a) return 0.0;
nuclear@5: 	if(x >= b) return 1.0;
nuclear@5: 
nuclear@5: 	x = (x - a) / (b - a);
nuclear@5: 	return x * x * (3.0 - 2.0 * x);
nuclear@5: }