nuclear@0: #include <stdio.h>
nuclear@0: #include <stdlib.h>
nuclear@0: #include <string.h>
nuclear@0: #include <math.h>
nuclear@17: #include <limits.h>
nuclear@0: #include <assert.h>
nuclear@21: #include "vmath.h"
nuclear@0: #include "mingl.h"
nuclear@0: #include "mglimpl.h"
nuclear@0: 
nuclear@3: 
nuclear@0: #define DOT(a, b)	((a).x * (b).x + (a).y * (b).y + (a).z * (b).z)
nuclear@0: 
nuclear@11: #define NORMALIZE(v)	\
nuclear@11: 	do { \
nuclear@11: 		float mag = sqrt(DOT(v, v)); \
nuclear@11: 		if(fabs(mag) > 1e-6) { \
nuclear@11: 			float invmag = 1.0 / mag; \
nuclear@11: 			(v).x *= invmag; \
nuclear@11: 			(v).y *= invmag; \
nuclear@11: 			(v).z *= invmag; \
nuclear@11: 		} \
nuclear@11: 	} while(0)
nuclear@11: 
nuclear@0: static void transform(vec4_t *res, vec4_t *v, float *mat);
nuclear@0: static void transform3(vec3_t *res, vec3_t *v, float *mat);
nuclear@0: static void vertex_proc(struct vertex *vert);
nuclear@3: static int calc_shiftmask(int val, int *shiftp, unsigned int *maskp);
nuclear@0: 
nuclear@0: static struct state st;
nuclear@0: static struct framebuffer fb;
nuclear@0: 
nuclear@0: int mgl_init(int width, int height)
nuclear@0: {
nuclear@0: 	int i;
nuclear@0: 
nuclear@0: 	st.flags = 0;
nuclear@0: 	st.mmode = 0;
nuclear@0: 
nuclear@0: 	mgl_front_face(MGL_CCW);
nuclear@0: 	mgl_cull_face(MGL_BACK);
nuclear@0: 
nuclear@0: 	st.curv.cidx = 0;
nuclear@0: 	st.curv.energy = 1.0;
nuclear@0: 	st.curv.norm.x = st.curv.norm.y = st.curv.norm.z = 0.0;
nuclear@0: 
nuclear@0: 	if(!(fb.pixels = malloc(width * height))) {
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 	fb.width = width;
nuclear@0: 	fb.height = height;
nuclear@0: 	fb.zbuf = 0;
nuclear@0: 
nuclear@0: 	if(mgl_rast_init(&st, &fb) == -1) {
nuclear@0: 		free(fb.pixels);
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	st.mtop[0] = st.mtop[1] = 0;
nuclear@0: 
nuclear@0: 	mgl_matrix_mode(MGL_MODELVIEW);
nuclear@0: 	mgl_load_identity();
nuclear@0: 	mgl_matrix_mode(MGL_PROJECTION);
nuclear@0: 	mgl_load_identity();
nuclear@0: 
nuclear@0: 	/* initial viewport in the size of the framebuffer */
nuclear@0: 	st.vp[0] = st.vp[1] = 0;
nuclear@0: 	st.vp[2] = width;
nuclear@0: 	st.vp[3] = height;
nuclear@0: 
nuclear@0: 	st.col_range = 256;
nuclear@0: 	for(i=0; i<MAX_LIGHTS; i++) {
nuclear@11: 		st.lpos[i].x = st.lpos[i].y = st.lpos[i].w = 0.0f;
nuclear@11: 		st.lpos[i].z = 1.0f;
nuclear@0: 		st.lint[i] = 0.0f;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_free(void)
nuclear@0: {
nuclear@9: 	int i;
nuclear@9: 
nuclear@0: 	mgl_rast_cleanup();
nuclear@0: 	free(fb.pixels);
nuclear@9: 	fb.pixels = 0;
nuclear@9: 
nuclear@9: 	if(fb.zbuf) {
nuclear@9: 		for(i=0; i<fb.num_ztiles; i++) {
nuclear@9: 			free(fb.zbuf[i]);
nuclear@9: 		}
nuclear@9: 		free(fb.zbuf);
nuclear@9: 		fb.zbuf = 0;
nuclear@9: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: unsigned char *mgl_framebuffer(void)
nuclear@0: {
nuclear@0: 	return fb.pixels;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_clear(int cidx)
nuclear@0: {
nuclear@0: 	memset(fb.pixels, cidx, fb.width * fb.height);
nuclear@0: }
nuclear@0: 
nuclear@9: void mgl_clear_depth(void)
nuclear@9: {
nuclear@9: 	int i;
nuclear@9: 
nuclear@9: 	if(!fb.zbuf) {
nuclear@9: 		long num_pixels = (long)fb.width * (long)fb.height;
nuclear@9: 		fb.num_ztiles = (num_pixels + ZTILE_SIZE - 1) / ZTILE_SIZE;
nuclear@9: 
nuclear@9: 		if(!(fb.zbuf = malloc(fb.num_ztiles * sizeof *fb.zbuf))) {
nuclear@9: 			fprintf(stderr, "failed to allocate ztile array\n");
nuclear@9: 			abort();
nuclear@9: 		}
nuclear@9: 
nuclear@9: 		for(i=0; i<fb.num_ztiles; i++) {
nuclear@9: 			if(!(fb.zbuf[i] = malloc(ZTILE_SIZE * 2))) {
nuclear@9: 				fprintf(stderr, "failed to allocate ztile %d\n", i);
nuclear@9: 				abort();
nuclear@9: 			}
nuclear@9: 			memset(fb.zbuf[i], 0xff, ZTILE_SIZE * 2);
nuclear@9: 		}
nuclear@9: 		return;
nuclear@9: 	}
nuclear@9: 
nuclear@9: 	for(i=0; i<fb.num_ztiles; i++) {
nuclear@9: 		memset(fb.zbuf[i], 0xff, ZTILE_SIZE * 2);
nuclear@9: 	}
nuclear@9: }
nuclear@9: 
nuclear@0: void mgl_enable(unsigned int bit)
nuclear@0: {
nuclear@0: 	st.flags |= bit;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_disable(unsigned int bit)
nuclear@0: {
nuclear@0: 	st.flags &= ~bit;
nuclear@0: }
nuclear@0: 
nuclear@3: int mgl_isenabled(unsigned int bit)
nuclear@3: {
nuclear@3: 	return (st.flags & bit) != 0;
nuclear@3: }
nuclear@3: 
nuclear@0: void mgl_front_face(int ff)
nuclear@0: {
nuclear@0: 	st.frontface = ff;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_cull_face(int cf)
nuclear@0: {
nuclear@0: 	st.cullface = cf;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_color_range(int rng)
nuclear@0: {
nuclear@0: 	st.col_range = rng;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_light_intensity(int ltidx, float intens)
nuclear@0: {
nuclear@0: 	assert(ltidx >= 0 && ltidx < MAX_LIGHTS);
nuclear@0: 	st.lint[ltidx] = intens;
nuclear@0: }
nuclear@0: 
nuclear@11: void mgl_light_position(int ltidx, float x, float y, float z, float w)
nuclear@0: {
nuclear@11: 	vec4_t pos;
nuclear@0: 	assert(ltidx >= 0 && ltidx < MAX_LIGHTS);
nuclear@0: 
nuclear@11: 	pos.x = x;
nuclear@11: 	pos.y = y;
nuclear@11: 	pos.z = z;
nuclear@11: 	pos.w = w;
nuclear@11: 	transform(&st.lpos[ltidx], &pos, st.matrix[MGL_MODELVIEW][st.mtop[MGL_MODELVIEW]]);
nuclear@0: 
nuclear@11: 	if(fabs(st.lpos[ltidx].w) < 1e-6) {
nuclear@11: 		NORMALIZE(st.lpos[ltidx]);
nuclear@11: 	} else {
nuclear@11: 		st.lpos[ltidx].x /= st.lpos[ltidx].w;
nuclear@11: 		st.lpos[ltidx].y /= st.lpos[ltidx].w;
nuclear@11: 		st.lpos[ltidx].z /= st.lpos[ltidx].w;
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_begin(int prim)
nuclear@0: {
nuclear@0: 	st.prim = prim;
nuclear@0: 	st.vidx = 0;
nuclear@0: 
nuclear@0: 	st.ord = st.frontface;
nuclear@0: 	if(st.cullface == MGL_FRONT) {
nuclear@0: 		st.ord = st.frontface == MGL_CCW ? MGL_CW : MGL_CCW;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	/* select the correct rasterizer according to state */
nuclear@0: 	mgl_rast_prepare();
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_end(void)
nuclear@0: {
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_vertex2f(float x, float y)
nuclear@0: {
nuclear@0: 	mgl_vertex4f(x, y, 0.0f, 1.0f);
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_vertex3f(float x, float y, float z)
nuclear@0: {
nuclear@0: 	mgl_vertex4f(x, y, z, 1.0f);
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_vertex4f(float x, float y, float z, float w)
nuclear@0: {
nuclear@0: 	st.v[st.vidx].pos.x = x;
nuclear@0: 	st.v[st.vidx].pos.y = y;
nuclear@0: 	st.v[st.vidx].pos.z = z;
nuclear@0: 	st.v[st.vidx].pos.w = w;
nuclear@0: 	st.v[st.vidx].cidx = st.curv.cidx;
nuclear@0: 	st.v[st.vidx].energy = st.curv.energy;
nuclear@0: 	st.v[st.vidx].norm = st.curv.norm;
nuclear@0: 	st.v[st.vidx].tc = st.curv.tc;
nuclear@0: 
nuclear@0: 	vertex_proc(st.v + st.vidx);
nuclear@0: 
nuclear@0: 	if(++st.vidx >= st.prim) {
nuclear@0: 		switch(st.prim) {
nuclear@0: 		case MGL_POINTS:
nuclear@0: 			mgl_draw_point(st.v);
nuclear@0: 			break;
nuclear@0: 		case MGL_LINES:
nuclear@0: 			mgl_draw_line(st.v, st.v + 1);
nuclear@0: 			break;
nuclear@0: 		case MGL_TRIANGLES:
nuclear@0: 		case MGL_QUADS:
nuclear@0: 			mgl_draw_poly(st.v, st.prim);
nuclear@0: 			break;
nuclear@0: 		default:
nuclear@0: 			fprintf(stderr, "invalid primitive: %d\n", st.prim);
nuclear@0: 			abort();
nuclear@0: 		}
nuclear@0: 		st.vidx = 0;
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_color1f(float energy)
nuclear@0: {
nuclear@0: 	st.curv.energy = energy;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_index(int c)
nuclear@0: {
nuclear@0: 	st.curv.cidx = c;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_normal(float x, float y, float z)
nuclear@0: {
nuclear@0: 	st.curv.norm.x = x;
nuclear@0: 	st.curv.norm.y = y;
nuclear@0: 	st.curv.norm.z = z;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_texcoord2f(float x, float y)
nuclear@0: {
nuclear@0: 	st.curv.tc.x = x;
nuclear@0: 	st.curv.tc.y = y;
nuclear@0: }
nuclear@0: 
nuclear@0: static void transform(vec4_t *res, vec4_t *v, float *mat)
nuclear@0: {
nuclear@0: 	res->x = mat[0] * v->x + mat[4] * v->y + mat[8] * v->z + mat[12] * v->w;
nuclear@0: 	res->y = mat[1] * v->x + mat[5] * v->y + mat[9] * v->z + mat[13] * v->w;
nuclear@0: 	res->z = mat[2] * v->x + mat[6] * v->y + mat[10] * v->z + mat[14] * v->w;
nuclear@0: 	res->w = mat[3] * v->x + mat[7] * v->y + mat[11] * v->z + mat[15] * v->w;
nuclear@0: }
nuclear@0: 
nuclear@0: /* the matrix is 4x4 (16 floats), just ignoring anything out of the 3x3 */
nuclear@0: static void transform3(vec3_t *res, vec3_t *v, float *mat)
nuclear@0: {
nuclear@0: 	res->x = mat[0] * v->x + mat[4] * v->y + mat[8] * v->z;
nuclear@0: 	res->y = mat[1] * v->x + mat[5] * v->y + mat[9] * v->z;
nuclear@0: 	res->z = mat[2] * v->x + mat[6] * v->y + mat[10] * v->z;
nuclear@0: }
nuclear@0: 
nuclear@0: static void vertex_proc(struct vertex *vert)
nuclear@0: {
nuclear@0: 	vec4_t pview, pclip;
nuclear@0: 
nuclear@0: 	float *mvmat = st.matrix[MGL_MODELVIEW][st.mtop[MGL_MODELVIEW]];
nuclear@0: 	float *pmat = st.matrix[MGL_PROJECTION][st.mtop[MGL_PROJECTION]];
nuclear@0: 
nuclear@0: 	/* modelview transformation */
nuclear@0: 	transform(&pview, &vert->pos, mvmat);
nuclear@0: 
nuclear@0: 	if(st.flags & MGL_LIGHTING) {
nuclear@0: 		if((st.flags & MGL_SMOOTH) || st.vidx == 0) {
nuclear@0: 			int i;
nuclear@0: 			vec3_t norm;
nuclear@0: 			float irrad = 0.0f;
nuclear@0: 
nuclear@0: 			transform3(&norm, &vert->norm, mvmat);
nuclear@0: 
nuclear@0: 			for(i=0; i<MAX_LIGHTS; i++) {
nuclear@0: 				if(st.lint[i] > 1e-6f) {
nuclear@11: 					float ndotl;
nuclear@11: 					vec3_t ldir;
nuclear@11: 
nuclear@11: 					if(st.lpos[i].w == 0.0) {
nuclear@11: 						ldir.x = st.lpos[i].x;
nuclear@11: 						ldir.y = st.lpos[i].y;
nuclear@11: 						ldir.z = st.lpos[i].z;
nuclear@11: 					} else {
nuclear@11: 						ldir.x = st.lpos[i].x - pview.x;
nuclear@11: 						ldir.y = st.lpos[i].y - pview.y;
nuclear@11: 						ldir.z = st.lpos[i].z - pview.z;
nuclear@11: 
nuclear@11: 						NORMALIZE(ldir);
nuclear@11: 					}
nuclear@11: 
nuclear@11: 					ndotl = DOT(norm, ldir);
nuclear@0: 					if(ndotl < 0.0) {
nuclear@0: 						ndotl = 0.0;
nuclear@0: 					}
nuclear@0: 					irrad += ndotl * st.lint[i];
nuclear@0: 				}
nuclear@0: 			}
nuclear@0: 			vert->energy = irrad;
nuclear@0: 		} else {
nuclear@0: 			vert->energy = st.v[0].energy;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	transform(&pclip, &pview, pmat);
nuclear@0: 	/* TODO clipping in homogenous clip space */
nuclear@0: 
nuclear@0: 	if(pclip.w < 1e-6 && pclip.w > -1e-6) {
nuclear@0: 		vert->pos.x = vert->pos.y = vert->pos.z = vert->pos.w = 0.0f;
nuclear@0: 		return;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	/* perspective division */
nuclear@0: 	vert->pos.x = pclip.x / pclip.w;
nuclear@0: 	vert->pos.y = pclip.y / pclip.w;
nuclear@0: 	vert->pos.z = pclip.z / pclip.w;
nuclear@0: 	vert->pos.w = pclip.w;
nuclear@0: 
nuclear@0: 	/* viewport transformation */
nuclear@0: 	vert->pos.x = st.vp[0] + st.vp[2] * (vert->pos.x * 0.5 + 0.5);
nuclear@0: 	vert->pos.y = st.vp[1] + st.vp[3] * (-vert->pos.y * 0.5 + 0.5);
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_viewport(int x, int y, int width, int height)
nuclear@0: {
nuclear@0: 	st.vp[0] = x;
nuclear@0: 	st.vp[1] = y;
nuclear@0: 	st.vp[2] = width;
nuclear@0: 	st.vp[3] = height;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_matrix_mode(int mmode)
nuclear@0: {
nuclear@0: 	st.mmode = mmode;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_push_matrix(void)
nuclear@0: {
nuclear@0: 	float *topmat;
nuclear@0: 	if(st.mtop[st.mmode] >= MATRIX_STACK_SIZE - 1) {
nuclear@0: 		fprintf(stderr, "mgl_push_matrix: stack overflow\n");
nuclear@0: 		abort();
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	topmat = st.matrix[st.mmode][st.mtop[st.mmode]];
nuclear@0: 	memcpy(topmat + 16, topmat, 16 * sizeof *topmat);
nuclear@0: 	st.mmode++;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_pop_matrix(void)
nuclear@0: {
nuclear@0: 	if(st.mtop[st.mmode] <= 0) {
nuclear@0: 		fprintf(stderr, "mgl_pop_matrix: stack underflow\n");
nuclear@0: 		abort();
nuclear@0: 	}
nuclear@0: 	st.mtop[st.mmode]--;
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_load_matrix(float *mat)
nuclear@0: {
nuclear@0: 	float *dest = st.matrix[st.mmode][st.mtop[st.mmode]];
nuclear@0: 	memcpy(dest, mat, 16 * sizeof *dest);
nuclear@0: }
nuclear@0: 
nuclear@17: #define M(i,j)	(((i) << 2) + (j))
nuclear@0: void mgl_mult_matrix(float *m2)
nuclear@0: {
nuclear@0: 	int i, j;
nuclear@0: 	float m1[16];
nuclear@0: 	float *dest = st.matrix[st.mmode][st.mtop[st.mmode]];
nuclear@0: 
nuclear@0: 	memcpy(m1, dest, sizeof m1);
nuclear@0: 
nuclear@0: 	for(i=0; i<4; i++) {
nuclear@0: 		for(j=0; j<4; j++) {
nuclear@0: 			dest[M(i,j)] = m1[M(0,j)] * m2[M(i,0)] +
nuclear@0: 				m1[M(1,j)] * m2[M(i,1)] +
nuclear@0: 				m1[M(2,j)] * m2[M(i,2)] +
nuclear@0: 				m1[M(3,j)] * m2[M(i,3)];
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_load_identity(void)
nuclear@0: {
nuclear@0: 	static float id[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0: 	mgl_load_matrix((float*)id);
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_translate(float x, float y, float z)
nuclear@0: {
nuclear@0: 	float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0: 	xform[12] = x;
nuclear@0: 	xform[13] = y;
nuclear@0: 	xform[14] = z;
nuclear@0: 	mgl_mult_matrix(xform);
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_rotate(float deg, float x, float y, float z)
nuclear@0: {
nuclear@0: 	float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0: 
nuclear@0: 	float angle = M_PI * deg / 180.0f;
nuclear@0: 	float sina = sin(angle);
nuclear@0: 	float cosa = cos(angle);
nuclear@0: 	float one_minus_cosa = 1.0f - cosa;
nuclear@0: 	float nxsq = x * x;
nuclear@0: 	float nysq = y * y;
nuclear@0: 	float nzsq = z * z;
nuclear@0: 
nuclear@0: 	xform[0] = nxsq + (1.0f - nxsq) * cosa;
nuclear@0: 	xform[4] = x * y * one_minus_cosa - z * sina;
nuclear@0: 	xform[8] = x * z * one_minus_cosa + y * sina;
nuclear@0: 	xform[1] = x * y * one_minus_cosa + z * sina;
nuclear@0: 	xform[5] = nysq + (1.0 - nysq) * cosa;
nuclear@0: 	xform[9] = y * z * one_minus_cosa - x * sina;
nuclear@0: 	xform[2] = x * z * one_minus_cosa - y * sina;
nuclear@0: 	xform[6] = y * z * one_minus_cosa + x * sina;
nuclear@0: 	xform[10] = nzsq + (1.0 - nzsq) * cosa;
nuclear@0: 
nuclear@0: 	mgl_mult_matrix(xform);
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_scale(float x, float y, float z)
nuclear@0: {
nuclear@0: 	float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0: 	xform[0] = x;
nuclear@0: 	xform[5] = y;
nuclear@0: 	xform[10] = z;
nuclear@0: 	mgl_mult_matrix(xform);
nuclear@0: }
nuclear@0: 
nuclear@0: void gl_ortho(float left, float right, float bottom, float top, float nr, float fr)
nuclear@0: {
nuclear@0: 	float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0: 
nuclear@0: 	float dx = right - left;
nuclear@0: 	float dy = top - bottom;
nuclear@0: 	float dz = fr - nr;
nuclear@0: 
nuclear@0: 	float tx = -(right + left) / dx;
nuclear@0: 	float ty = -(top + bottom) / dy;
nuclear@0: 	float tz = -(fr + nr) / dz;
nuclear@0: 
nuclear@0: 	float sx = 2.0 / dx;
nuclear@0: 	float sy = 2.0 / dy;
nuclear@0: 	float sz = -2.0 / dz;
nuclear@0: 
nuclear@0: 	xform[0] = sx;
nuclear@0: 	xform[5] = sy;
nuclear@0: 	xform[10] = sz;
nuclear@0: 	xform[12] = tx;
nuclear@0: 	xform[13] = ty;
nuclear@0: 	xform[14] = tz;
nuclear@0: 
nuclear@0: 	mgl_mult_matrix(xform);
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_frustum(float left, float right, float bottom, float top, float nr, float fr)
nuclear@0: {
nuclear@0: 	float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0: 
nuclear@0: 	float dx = right - left;
nuclear@0: 	float dy = top - bottom;
nuclear@0: 	float dz = fr - nr;
nuclear@0: 
nuclear@0: 	float a = (right + left) / dx;
nuclear@0: 	float b = (top + bottom) / dy;
nuclear@0: 	float c = -(fr + nr) / dz;
nuclear@0: 	float d = -2.0 * fr * nr / dz;
nuclear@0: 
nuclear@0: 	xform[0] = 2.0 * nr / dx;
nuclear@0: 	xform[5] = 2.0 * nr / dy;
nuclear@0: 	xform[8] = a;
nuclear@0: 	xform[9] = b;
nuclear@0: 	xform[10] = c;
nuclear@0: 	xform[11] = -1.0f;
nuclear@0: 	xform[14] = d;
nuclear@0: 
nuclear@0: 	mgl_mult_matrix(xform);
nuclear@0: }
nuclear@0: 
nuclear@0: void mgl_perspective(float vfov, float aspect, float nr, float fr)
nuclear@0: {
nuclear@0: 	float vfov_rad = M_PI * vfov / 180.0;
nuclear@0: 	float x = nr * tan(vfov_rad / 2.0);
nuclear@0: 	mgl_frustum(-aspect * x, aspect * x, -x, x, nr, fr);
nuclear@0: }
nuclear@3: 
nuclear@3: void mgl_teximage(int width, int height, unsigned char *pixels)
nuclear@3: {
nuclear@3: 	st.tex.width = width;
nuclear@3: 	st.tex.height = height;
nuclear@3: 	st.tex.pixels = pixels;
nuclear@3: 
nuclear@3: 	if(calc_shiftmask(width, &st.tex.xshift, &st.tex.xmask) == -1 ||
nuclear@3: 			calc_shiftmask(height, &st.tex.yshift, &st.tex.ymask) == -1) {
nuclear@3: 		st.tex.pixels = 0;
nuclear@3: 	}
nuclear@3: }
nuclear@3: 
nuclear@3: #define MAX_SHIFT	12
nuclear@3: static int calc_shiftmask(int val, int *shiftp, unsigned int *maskp)
nuclear@3: {
nuclear@3: 	int i;
nuclear@3: 
nuclear@3: 	for(i=0; i<MAX_SHIFT; i++) {
nuclear@3: 		if((val >> i) == 1) {
nuclear@3: 			*shiftp = i;
nuclear@17: 			*maskp = ~(UINT_MAX << i);
nuclear@3: 			return 0;
nuclear@3: 		}
nuclear@3: 	}
nuclear@3: 	return -1;
nuclear@3: }