1.1 --- a/src/vr.cc	Tue Oct 01 12:51:20 2013 +0300
     1.2 +++ b/src/vr.cc	Wed Oct 02 04:09:37 2013 +0300
     1.3 @@ -10,13 +10,40 @@
     1.4  #include <malloc.h>
     1.5  #endif
     1.6  
     1.7 +#define USUB	28
     1.8 +#define VSUB	40
     1.9 +
    1.10 +/* these are just used for the shaderless precomputed distortion method */
    1.11 +struct Mesh {
    1.12 +	int prim;
    1.13 +	int num_verts, num_faces;
    1.14 +	unsigned int vbo;
    1.15 +	unsigned int ibo;
    1.16 +};
    1.17 +struct Vertex {
    1.18 +	float x, y, z;
    1.19 +	float tx, ty;
    1.20 +};
    1.21 +
    1.22 +
    1.23  static void init_ctx();
    1.24  static bool init_ovr();
    1.25  static bool init_sdr();
    1.26  
    1.27 +static Mesh gen_view_mesh(int usub, int vsub, float aspect, float lens_center_offset,
    1.28 +		float scale, const float *dist_factors, float tex_scale_x, float tex_scale_y);
    1.29 +static void distort_texcoords(float *tc, float aspect, float lens_center_offset, float scale, const float *dist_factors);
    1.30 +static float barrel_scale(float rad, const float *k);
    1.31 +
    1.32  VRContext vr_ctx;
    1.33  static unsigned int sdrprog;
    1.34  
    1.35 +static Mesh wrapmesh[2];
    1.36 +static bool mesh_valid;
    1.37 +
    1.38 +bool dbg_enable;
    1.39 +
    1.40 +
    1.41  extern "C" int vr_init(enum vr_init_mode mode)
    1.42  {
    1.43  	glewInit();
    1.44 @@ -338,49 +365,204 @@
    1.45  		{-1, -1, 0, 1},
    1.46  		{0, -1, 1, 1}
    1.47  	};
    1.48 +	static const float quad_trans[3] = {0, -1, 1};
    1.49 +	static const float quad_scale[3] = {1, 0.5, 0.5};
    1.50  	static const float offs_scale[3] = {0.0, -1.0, 1.0};
    1.51 +	static int prev_tex_scale_x, prev_tex_scale_y;
    1.52  
    1.53  	glPushAttrib(GL_ENABLE_BIT);
    1.54  	glDisable(GL_DEPTH_TEST);
    1.55  	glDisable(GL_LIGHTING);
    1.56 -	glEnable(GL_TEXTURE_2D);
    1.57 +	glDisable(GL_CULL_FACE);
    1.58 +
    1.59 +	glMatrixMode(GL_PROJECTION);
    1.60 +	glPushMatrix();
    1.61 +	glLoadIdentity();
    1.62  
    1.63  	glMatrixMode(GL_MODELVIEW);
    1.64  	glPushMatrix();
    1.65  	glLoadIdentity();
    1.66  
    1.67 -	glMatrixMode(GL_PROJECTION);
    1.68 -	glPushMatrix();
    1.69 -	glLoadIdentity();
    1.70 +	if(!dbg_enable) {
    1.71 +		glUseProgram(sdrprog);
    1.72  
    1.73 -	glUseProgram(sdrprog);
    1.74 +		if(sdrprog) {
    1.75 +			int loc;
    1.76 +			if((loc = glGetUniformLocation(sdrprog, "lens_center_offset")) != -1) {
    1.77 +				float offset = vr_ctx.info.lens_center_offset * offs_scale[eye];
    1.78 +				glUniform1f(loc, offset);
    1.79 +			}
    1.80  
    1.81 -	if(sdrprog) {
    1.82 -		int loc;
    1.83 -		if((loc = glGetUniformLocation(sdrprog, "lens_center_offset")) != -1) {
    1.84 -			float offset = vr_ctx.info.lens_center_offset * offs_scale[eye];
    1.85 -			glUniform1f(loc, offset);
    1.86 +			if((loc = glGetUniformLocation(sdrprog, "tex_scale")) != -1) {
    1.87 +				glUniform2f(loc, tex_scale_x, tex_scale_y);
    1.88 +			}
    1.89  		}
    1.90  
    1.91 -		if((loc = glGetUniformLocation(sdrprog, "tex_scale")) != -1) {
    1.92 -			glUniform2f(loc, tex_scale_x, tex_scale_y);
    1.93 +		glBindTexture(GL_TEXTURE_2D, tex);
    1.94 +		glBegin(GL_QUADS);
    1.95 +		glColor4f(1, 1, 1, 1);
    1.96 +		glTexCoord2f(0, 0); glVertex2f(rects[eye][0], rects[eye][1]);
    1.97 +		glTexCoord2f(1, 0); glVertex2f(rects[eye][2], rects[eye][1]);
    1.98 +		glTexCoord2f(1, 1); glVertex2f(rects[eye][2], rects[eye][3]);
    1.99 +		glTexCoord2f(0, 1); glVertex2f(rects[eye][0], rects[eye][3]);
   1.100 +		glEnd();
   1.101 +
   1.102 +		glUseProgram(0);
   1.103 +
   1.104 +	} else {
   1.105 +
   1.106 +		if(!mesh_valid || tex_scale_x != prev_tex_scale_x || tex_scale_y != prev_tex_scale_y) {
   1.107 +			for(int i=0; i<2; i++) {
   1.108 +				int eye = i + VR_EYE_LEFT;
   1.109 +
   1.110 +				if(wrapmesh[i].vbo) {
   1.111 +					glDeleteBuffers(1, &wrapmesh[i].vbo);
   1.112 +				}
   1.113 +				if(wrapmesh[i].ibo) {
   1.114 +					glDeleteBuffers(1, &wrapmesh[i].ibo);
   1.115 +				}
   1.116 +
   1.117 +				float aspect = vr_ctx.info.aspect / 2.0;
   1.118 +				float offset = vr_ctx.info.lens_center_offset * offs_scale[eye];
   1.119 +				wrapmesh[i] = gen_view_mesh(USUB, VSUB, aspect, offset, vr_ctx.info.scale, vr_ctx.info.distort,
   1.120 +					tex_scale_x, tex_scale_y);
   1.121 +			}
   1.122 +			mesh_valid = true;
   1.123 +			prev_tex_scale_x = tex_scale_x;
   1.124 +			prev_tex_scale_y = tex_scale_y;
   1.125  		}
   1.126 +
   1.127 +		glScalef(quad_scale[eye], 1.0, 1.0);
   1.128 +		glTranslatef(quad_trans[eye], 0, 0);
   1.129 +
   1.130 +		glUseProgram(0);
   1.131 +		glBindTexture(GL_TEXTURE_2D, tex);
   1.132 +		glEnable(GL_TEXTURE_2D);
   1.133 +
   1.134 +		glColor3f(1, 1, 1);
   1.135 +
   1.136 +		glEnableClientState(GL_VERTEX_ARRAY);
   1.137 +		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
   1.138 +
   1.139 +		int meshidx = eye - VR_EYE_LEFT;
   1.140 +		glBindBuffer(GL_ARRAY_BUFFER, wrapmesh[meshidx].vbo);
   1.141 +		glVertexPointer(3, GL_FLOAT, sizeof(Vertex), 0);
   1.142 +		glTexCoordPointer(2, GL_FLOAT, sizeof(Vertex), (void*)offsetof(Vertex, tx));
   1.143 +
   1.144 +		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, wrapmesh[meshidx].ibo);
   1.145 +		glDrawElements(GL_TRIANGLES, wrapmesh[meshidx].num_faces * 3, GL_UNSIGNED_INT, 0);
   1.146 +
   1.147 +		glBindBuffer(GL_ARRAY_BUFFER, 0);
   1.148 +		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
   1.149 +
   1.150 +		glDisableClientState(GL_VERTEX_ARRAY);
   1.151 +		glDisableClientState(GL_TEXTURE_COORD_ARRAY);
   1.152  	}
   1.153  
   1.154 -	glBindTexture(GL_TEXTURE_2D, tex);
   1.155 -	glBegin(GL_QUADS);
   1.156 -	glColor4f(1, 1, 1, 1);
   1.157 -	glTexCoord2f(0, 0); glVertex2f(rects[eye][0], rects[eye][1]);
   1.158 -	glTexCoord2f(1, 0); glVertex2f(rects[eye][2], rects[eye][1]);
   1.159 -	glTexCoord2f(1, 1); glVertex2f(rects[eye][2], rects[eye][3]);
   1.160 -	glTexCoord2f(0, 1); glVertex2f(rects[eye][0], rects[eye][3]);
   1.161 -	glEnd();
   1.162 -
   1.163 -	glUseProgram(0);
   1.164 -
   1.165 +	glMatrixMode(GL_PROJECTION);
   1.166  	glPopMatrix();
   1.167  	glMatrixMode(GL_MODELVIEW);
   1.168  	glPopMatrix();
   1.169  
   1.170  	glPopAttrib();
   1.171  }
   1.172 +
   1.173 +static Mesh gen_view_mesh(int usub, int vsub, float aspect, float lens_center_offset,
   1.174 +		float scale, const float *dist_factors, float tex_scale_x, float tex_scale_y)
   1.175 +{
   1.176 +	int uverts = usub + 1;
   1.177 +	int vverts = vsub + 1;
   1.178 +
   1.179 +	int num_verts = uverts * vverts;
   1.180 +	int num_quads = usub * vsub;
   1.181 +	int num_tris = num_quads * 2;
   1.182 +
   1.183 +	Vertex *varr = new Vertex[num_verts];
   1.184 +	unsigned int *iarr = new unsigned int[num_tris * 3];
   1.185 +
   1.186 +	float du = 1.0 / (float)usub;
   1.187 +	float dv = 1.0 / (float)vsub;
   1.188 +
   1.189 +	Vertex *vptr = varr;
   1.190 +	for(int i=0; i<vverts; i++) {
   1.191 +		float v = (float)i * dv;
   1.192 +		float y = 2.0 * v - 1.0;
   1.193 +
   1.194 +		for(int j=0; j<uverts; j++) {
   1.195 +			float u = (float)j * du;
   1.196 +			float x = 2.0 * u - 1.0;
   1.197 +			float tc[2] = {u, v};
   1.198 +
   1.199 +			distort_texcoords(tc, aspect, lens_center_offset, scale, dist_factors);
   1.200 +
   1.201 +			vptr->x = x;
   1.202 +			vptr->y = y;
   1.203 +			vptr->z = 0;
   1.204 +			vptr->tx = tc[0] * tex_scale_x;
   1.205 +			vptr->ty = tc[1] * tex_scale_y;
   1.206 +			vptr++;
   1.207 +		}
   1.208 +	}
   1.209 +
   1.210 +	unsigned int *iptr = iarr;
   1.211 +	for(int i=0; i<vsub; i++) {
   1.212 +		for(int j=0; j<usub; j++) {
   1.213 +			*iptr++ = i * uverts + j;
   1.214 +			*iptr++ = (i + 1) * uverts + j;
   1.215 +			*iptr++ = (i + 1) * uverts + (j + 1);
   1.216 +
   1.217 +			*iptr++ = i * uverts + j;
   1.218 +			*iptr++ = (i + 1) * uverts + (j + 1);
   1.219 +			*iptr++ = i * uverts + (j + 1);
   1.220 +		}
   1.221 +	}
   1.222 +
   1.223 +	unsigned int buf[2];
   1.224 +	glGenBuffers(2, buf);
   1.225 +	glBindBuffer(GL_ARRAY_BUFFER, buf[0]);
   1.226 +	glBufferData(GL_ARRAY_BUFFER, num_verts * sizeof *varr, varr, GL_STATIC_DRAW);
   1.227 +	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buf[1]);
   1.228 +	glBufferData(GL_ELEMENT_ARRAY_BUFFER, num_tris * 3 * sizeof *iarr, iarr, GL_STATIC_DRAW); 
   1.229 +
   1.230 +	delete [] varr;
   1.231 +	delete [] iarr;
   1.232 +
   1.233 +	Mesh mesh;
   1.234 +	mesh.prim = GL_TRIANGLES;
   1.235 +	mesh.num_verts = num_verts;
   1.236 +	mesh.num_faces = num_tris;
   1.237 +	mesh.vbo = buf[0];
   1.238 +	mesh.ibo = buf[1];
   1.239 +	return mesh;
   1.240 +}
   1.241 +
   1.242 +static void distort_texcoords(float *tc, float aspect, float lens_center_offset, float scale, const float *dist_factors)
   1.243 +{
   1.244 +	// map tc [0, 1] -> [-1, 1]
   1.245 +	float ptx = tc[0] * 2.0 - 1.0;
   1.246 +	float pty = tc[1] * 2.0 - 1.0;
   1.247 +
   1.248 +	ptx += lens_center_offset * 2.0;
   1.249 +	pty /= aspect;	// correct for aspect ratio
   1.250 +
   1.251 +	float rad = barrel_scale(ptx * ptx + pty * pty, dist_factors);
   1.252 +	ptx *= rad;	// scale the point by the computer distortion radius
   1.253 +	pty *= rad;
   1.254 +
   1.255 +	ptx /= scale;
   1.256 +	pty /= scale;
   1.257 +
   1.258 +	pty *= aspect;
   1.259 +	ptx -= lens_center_offset * 2.0;
   1.260 +
   1.261 +	// map back to range [0, 1]
   1.262 +	tc[0] = ptx * 0.5 + 0.5;
   1.263 +	tc[1] = pty * 0.5 + 0.5;
   1.264 +}
   1.265 +
   1.266 +static float barrel_scale(float rad, const float *k)
   1.267 +{
   1.268 +	float radsq = rad * rad;
   1.269 +	float radquad = radsq * radsq;
   1.270 +	return k[0] + k[1] * radsq + k[2] * radquad + k[3] * radquad * radsq;
   1.271 +}