nuclear@2: /*
nuclear@2: SaneGL - a small library to bring back sanity to OpenGL ES 2.x
nuclear@2: Copyright (C) 2011  John Tsiombikas <nuclear@member.fsf.org>
nuclear@2: 
nuclear@2: This program is free software: you can redistribute it and/or modify
nuclear@2: it under the terms of the GNU General Public License as published by
nuclear@2: the Free Software Foundation, either version 3 of the License, or
nuclear@2: (at your option) any later version.
nuclear@2: 
nuclear@2: This program is distributed in the hope that it will be useful,
nuclear@2: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@2: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@2: GNU General Public License for more details.
nuclear@2: 
nuclear@2: You should have received a copy of the GNU General Public License
nuclear@2: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@2: */
nuclear@2: 
nuclear@2: #include <stdio.h>
nuclear@3: #include <stdlib.h>
nuclear@2: #include <string.h>
nuclear@1: #include <math.h>
nuclear@2: #include <assert.h>
nuclear@1: #include "sanegl.h"
nuclear@1: 
nuclear@1: #define MMODE_IDX(x)	((x) - GL_MODELVIEW)
nuclear@1: #define MAT_STACK_SIZE	32
nuclear@1: #define MAT_IDENT	{1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1}
nuclear@1: 
nuclear@1: #define MAX_VERTS	512
nuclear@1: 
nuclear@2: static void gl_draw_immediate(void);
nuclear@2: 
nuclear@1: typedef struct { float x, y; } vec2_t;
nuclear@1: typedef struct { float x, y, z; } vec3_t;
nuclear@1: typedef struct { float x, y, z, w; } vec4_t;
nuclear@1: 
nuclear@1: static int mm_idx = 0;
nuclear@1: static float mat_stack[3][MAT_STACK_SIZE][16] = {{MAT_IDENT}, {MAT_IDENT}, {MAT_IDENT}};
nuclear@1: static int stack_top[3];
nuclear@1: static float mat_mvp[16];
nuclear@1: static int mvp_valid;
nuclear@1: static int prim = -1;
nuclear@1: 
nuclear@1: static vec3_t cur_normal;
nuclear@1: static vec4_t cur_color, cur_attrib;
nuclear@1: static vec2_t cur_texcoord;
nuclear@1: 
nuclear@1: static vec4_t *vert_arr, *col_arr, *attr_arr;
nuclear@1: static vec3_t *norm_arr;
nuclear@1: static vec2_t *texc_arr;
nuclear@2: /*static unsigned int vbuf, cbuf, nbuf, tbuf, abuf;*/
nuclear@2: static int vloc, nloc, cloc, tloc, aloc = -1;
nuclear@2: 
nuclear@2: static int num_verts, vert_calls;
nuclear@2: static int cur_prog;
nuclear@1: 
nuclear@1: 
nuclear@1: void gl_matrix_mode(int mm)
nuclear@1: {
nuclear@1: 	mm_idx = MMODE_IDX(mm);
nuclear@1: }
nuclear@1: 
nuclear@1: void gl_push_matrix(void)
nuclear@1: {
nuclear@1: 	int top = stack_top[mm_idx];
nuclear@1: 
nuclear@1: 	memcpy(mat_stack[mm_idx][top + 1], mat_stack[mm_idx][top], 16 * sizeof(float));
nuclear@1: 	stack_top[mm_idx]++;
nuclear@1: 	mvp_valid = 0;
nuclear@1: }
nuclear@1: 
nuclear@1: void gl_pop_matrix(void)
nuclear@1: {
nuclear@1: 	stack_top[mm_idx]--;
nuclear@1: 	mvp_valid = 0;
nuclear@1: }
nuclear@1: 
nuclear@1: void gl_load_identity(void)
nuclear@1: {
nuclear@1: 	static const float idmat[] = MAT_IDENT;
nuclear@1: 	int top = stack_top[mm_idx];
nuclear@1: 	float *mat = mat_stack[mm_idx][top];
nuclear@1: 
nuclear@1: 	memcpy(mat, idmat, sizeof idmat);
nuclear@1: 	mvp_valid = 0;
nuclear@1: }
nuclear@1: 
nuclear@1: void gl_load_matrixf(const float *m)
nuclear@1: {
nuclear@1: 	int top = stack_top[mm_idx];
nuclear@1: 	float *mat = mat_stack[mm_idx][top];
nuclear@1: 
nuclear@1: 	memcpy(mat, m, 16 * sizeof *mat);
nuclear@1: 	mvp_valid = 0;
nuclear@1: }
nuclear@1: 
nuclear@1: #define M(i, j)	((i << 2) + j)
nuclear@1: 
nuclear@1: void gl_mult_matrixf(const float *m2)
nuclear@1: {
nuclear@1: 	int i, j;
nuclear@1: 	int top = stack_top[mm_idx];
nuclear@1: 	float *m1 = mat_stack[mm_idx][top];
nuclear@1: 	float res[16];
nuclear@1: 
nuclear@1: 	for(i=0; i<4; i++) {
nuclear@1: 		for(j=0; j<4; j++) {
nuclear@1: 			res[M(i,j)] = m1[M(i,0)] * m2[M(0,j)] +
nuclear@1: 						m1[M(i,1)] * m2[M(1,j)] +
nuclear@1: 						m1[M(i,2)] * m2[M(2,j)] +
nuclear@1: 						m1[M(i,3)] * m2[M(3,j)];
nuclear@1: 		}
nuclear@1: 	}
nuclear@1: 
nuclear@1: 	memcpy(m1, res, sizeof res);
nuclear@1: 	mvp_valid = 0;
nuclear@1: }
nuclear@1: 
nuclear@1: void gl_translatef(float x, float y, float z)
nuclear@1: {
nuclear@1: 	float mat[] = MAT_IDENT;
nuclear@1: 
nuclear@1: 	mat[12] = x;
nuclear@1: 	mat[13] = y;
nuclear@1: 	mat[14] = z;
nuclear@1: 
nuclear@1: 	gl_mult_matrixf(mat);
nuclear@1: }
nuclear@1: 
nuclear@1: void gl_rotatef(float angle, float x, float y, float z)
nuclear@1: {
nuclear@1: 	float mat[] = MAT_IDENT;
nuclear@1: 
nuclear@1: 	float angle_rad = M_PI * angle / 180.0;
nuclear@1: 	float sina = sin(angle_rad);
nuclear@1: 	float cosa = cos(angle_rad);
nuclear@1: 	float one_minus_cosa = 1.0 - cosa;
nuclear@1: 	float nxsq = x * x;
nuclear@1: 	float nysq = y * y;
nuclear@1: 	float nzsq = z * z;
nuclear@1: 
nuclear@1: 	mat[0] = nxsq + (1.0 - nxsq) * cosa;
nuclear@1: 	mat[4] = x * y * one_minus_cosa - z * sina;
nuclear@1: 	mat[8] = x * z * one_minus_cosa + y * sina;
nuclear@1: 	mat[1] = x * y * one_minus_cosa + z * sina;
nuclear@1: 	mat[5] = nysq + (1.0 - nysq) * cosa;
nuclear@1: 	mat[9] = y * z * one_minus_cosa - x * sina;
nuclear@1: 	mat[2] = x * z * one_minus_cosa - y * sina;
nuclear@1: 	mat[6] = y * z * one_minus_cosa + x * sina;
nuclear@1: 	mat[10] = nzsq + (1.0 - nzsq) * cosa;
nuclear@1: 
nuclear@1: 	gl_mult_matrixf(mat);
nuclear@1: }
nuclear@1: 
nuclear@1: void gl_scalef(float x, float y, float z)
nuclear@1: {
nuclear@1: 	float mat[] = MAT_IDENT;
nuclear@1: 
nuclear@1: 	mat[0] = x;
nuclear@1: 	mat[5] = y;
nuclear@1: 	mat[10] = z;
nuclear@1: 
nuclear@1: 	gl_mult_matrixf(mat);
nuclear@1: }
nuclear@1: 
nuclear@1: void gl_ortho(float left, float right, float bottom, float top, float near, float far)
nuclear@1: {
nuclear@1: 	float mat[] = MAT_IDENT;
nuclear@1: 
nuclear@1: 	float dx = right - left;
nuclear@1: 	float dy = top - bottom;
nuclear@1: 	float dz = far - near;
nuclear@1: 
nuclear@1: 	float tx = -(right + left) / dx;
nuclear@1: 	float ty = -(top + bottom) / dy;
nuclear@1: 	float tz = -(far + near) / dz;
nuclear@1: 
nuclear@1: 	float sx = 2.0 / dx;
nuclear@1: 	float sy = 2.0 / dy;
nuclear@1: 	float sz = -2.0 / dz;
nuclear@1: 
nuclear@1: 	mat[0] = sx;
nuclear@1: 	mat[5] = sy;
nuclear@1: 	mat[10] = sz;
nuclear@1: 	mat[12] = tx;
nuclear@1: 	mat[13] = ty;
nuclear@1: 	mat[14] = tz;
nuclear@1: 
nuclear@1: 	gl_mult_matrixf(mat);
nuclear@1: }
nuclear@1: 
nuclear@1: void gl_frustum(float left, float right, float bottom, float top, float near, float far)
nuclear@1: {
nuclear@1: 	float mat[] = MAT_IDENT;
nuclear@1: 
nuclear@1: 	float dx = right - left;
nuclear@1: 	float dy = top - bottom;
nuclear@1: 	float dz = far - near;
nuclear@1: 
nuclear@1: 	float a = (right + left) / dx;
nuclear@1: 	float b = (top + bottom) / dy;
nuclear@1: 	float c = -(far + near) / dz;
nuclear@1: 	float d = -2.0 * far * near / dz;
nuclear@1: 
nuclear@1: 	mat[0] = 2.0 * near / dx;
nuclear@1: 	mat[5] = 2.0 * near / dy;
nuclear@1: 	mat[8] = a;
nuclear@1: 	mat[9] = b;
nuclear@1: 	mat[10] = c;
nuclear@1: 	mat[11] = -1.0;
nuclear@1: 	mat[14] = d;
nuclear@1: 
nuclear@1: 	gl_mult_matrixf(mat);
nuclear@1: }
nuclear@1: 
nuclear@1: void glu_perspective(float vfov, float aspect, float near, float far)
nuclear@1: {
nuclear@1: 	float x = near * tan(vfov / 2.0);
nuclear@1: 	gl_frustum(-aspect * x, aspect * x, -x, x, near, far);
nuclear@1: }
nuclear@1: 
nuclear@1: void gl_apply_xform(unsigned int prog)
nuclear@1: {
nuclear@1: 	int loc, mvidx, pidx, tidx, mvtop, ptop, ttop;
nuclear@1: 
nuclear@1: 	mvidx = MMODE_IDX(GL_MODELVIEW);
nuclear@1: 	pidx = MMODE_IDX(GL_PROJECTION);
nuclear@1: 	tidx = MMODE_IDX(GL_TEXTURE);
nuclear@1: 
nuclear@1: 	mvtop = stack_top[mvidx];
nuclear@1: 	ptop = stack_top[pidx];
nuclear@1: 	ttop = stack_top[tidx];
nuclear@1: 
nuclear@2: 	assert(prog);
nuclear@2: 
nuclear@1: 	if((loc = glGetUniformLocation(prog, "matrix_modelview")) != -1) {
nuclear@2: 		glUniformMatrix4fv(loc, 1, 0, mat_stack[mvidx][mvtop]);
nuclear@1: 	}
nuclear@1: 
nuclear@1: 	if((loc = glGetUniformLocation(prog, "matrix_projection")) != -1) {
nuclear@2: 		glUniformMatrix4fv(loc, 1, 0, mat_stack[pidx][ptop]);
nuclear@1: 	}
nuclear@1: 
nuclear@1: 	if((loc = glGetUniformLocation(prog, "matrix_texture")) != -1) {
nuclear@2: 		glUniformMatrix4fv(loc, 1, 0, mat_stack[tidx][ttop]);
nuclear@1: 	}
nuclear@1: 
nuclear@1: 	if((loc = glGetUniformLocation(prog, "matrix_normal")) != -1) {
nuclear@1: 		float nmat[9];
nuclear@1: 
nuclear@1: 		nmat[0] = mat_stack[mvidx][mvtop][0];
nuclear@1: 		nmat[1] = mat_stack[mvidx][mvtop][1];
nuclear@1: 		nmat[2] = mat_stack[mvidx][mvtop][2];
nuclear@1: 		nmat[3] = mat_stack[mvidx][mvtop][4];
nuclear@1: 		nmat[4] = mat_stack[mvidx][mvtop][5];
nuclear@1: 		nmat[5] = mat_stack[mvidx][mvtop][6];
nuclear@1: 		nmat[6] = mat_stack[mvidx][mvtop][8];
nuclear@1: 		nmat[7] = mat_stack[mvidx][mvtop][9];
nuclear@1: 		nmat[8] = mat_stack[mvidx][mvtop][10];
nuclear@2: 		glUniformMatrix3fv(loc, 1, 0, nmat);
nuclear@1: 	}
nuclear@1: 
nuclear@1: 	if((loc = glGetUniformLocation(prog, "matrix_modelview_projection")) != -1) {
nuclear@1: 		if(!mvp_valid) {
nuclear@1: 			/* TODO calc mvp */
nuclear@1: 		}
nuclear@2: 		glUniformMatrix4fv(loc, 1, 0, mat_mvp);
nuclear@1: 	}
nuclear@1: }
nuclear@2: 
nuclear@2: 
nuclear@2: /* immediate mode rendering */
nuclear@2: void gl_begin(int p)
nuclear@2: {
nuclear@2: 	if(!vert_arr) {
nuclear@2: 		vert_arr = malloc(MAX_VERTS * sizeof *vert_arr);
nuclear@2: 		norm_arr = malloc(MAX_VERTS * sizeof *norm_arr);
nuclear@2: 		texc_arr = malloc(MAX_VERTS * sizeof *texc_arr);
nuclear@2: 		col_arr = malloc(MAX_VERTS * sizeof *col_arr);
nuclear@2: 		attr_arr = malloc(MAX_VERTS * sizeof *attr_arr);
nuclear@2: 		assert(vert_arr && norm_arr && texc_arr && col_arr && attr_arr);
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	prim = p;
nuclear@2: 	num_verts = vert_calls = 0;
nuclear@2: 
nuclear@2: 	glGetIntegerv(GL_CURRENT_PROGRAM, &cur_prog);
nuclear@2: 	assert(cur_prog);
nuclear@2: 
nuclear@2: 	gl_apply_xform(cur_prog);
nuclear@2: 
nuclear@2: 	vloc = glGetAttribLocation(cur_prog, "attr_vertex");
nuclear@2: 	nloc = glGetAttribLocation(cur_prog, "attr_normal");
nuclear@2: 	cloc = glGetAttribLocation(cur_prog, "attr_color");
nuclear@2: 	tloc = glGetAttribLocation(cur_prog, "attr_texcoord");
nuclear@2: }
nuclear@2: 
nuclear@2: void gl_end(void)
nuclear@2: {
nuclear@2: 	if(num_verts > 0) {
nuclear@2: 		gl_draw_immediate();
nuclear@2: 	}
nuclear@2: 	aloc = -1;
nuclear@2: }
nuclear@2: 
nuclear@2: static void gl_draw_immediate(void)
nuclear@2: {
nuclear@2: 	int glprim;
nuclear@2: 
nuclear@2: 	if(vloc == -1) {
nuclear@2: 		fprintf(stderr, "gl_draw_immediate call with vloc == -1\n");
nuclear@2: 		return;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	glprim = prim == GL_QUADS ? GL_TRIANGLES : prim;
nuclear@2: 
nuclear@2: 	glVertexAttribPointer(vloc, 4, GL_FLOAT, 0, 0, vert_arr);
nuclear@2: 	glEnableVertexAttribArray(vloc);
nuclear@2: 
nuclear@2: 	if(nloc != -1) {
nuclear@2: 		glVertexAttribPointer(nloc, 3, GL_FLOAT, 0, 0, norm_arr);
nuclear@2: 		glEnableVertexAttribArray(nloc);
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	if(cloc != -1) {
nuclear@2: 		glVertexAttribPointer(cloc, 4, GL_FLOAT, 0, 0, col_arr);
nuclear@2: 		glEnableVertexAttribArray(cloc);
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	if(tloc != -1) {
nuclear@2: 		glVertexAttribPointer(tloc, 2, GL_FLOAT, 0, 0, texc_arr);
nuclear@2: 		glEnableVertexAttribArray(tloc);
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	if(aloc != -1) {
nuclear@2: 		glVertexAttribPointer(aloc, 4, GL_FLOAT, 0, 0, attr_arr);
nuclear@2: 		glEnableVertexAttribArray(aloc);
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	glDrawArrays(glprim, 0, num_verts);
nuclear@2: 
nuclear@2: 	glDisableVertexAttribArray(vloc);
nuclear@2: 	if(nloc != -1) {
nuclear@2: 		glDisableVertexAttribArray(nloc);
nuclear@2: 	}
nuclear@2: 	if(cloc != -1) {
nuclear@2: 		glDisableVertexAttribArray(cloc);
nuclear@2: 	}
nuclear@2: 	if(tloc != -1) {
nuclear@2: 		glDisableVertexAttribArray(tloc);
nuclear@2: 	}
nuclear@2: 	if(aloc != -1) {
nuclear@2: 		glDisableVertexAttribArray(aloc);
nuclear@2: 	}
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: void gl_vertex2f(float x, float y)
nuclear@2: {
nuclear@2: 	gl_vertex4f(x, y, 0.0f, 1.0f);
nuclear@2: }
nuclear@2: 
nuclear@2: void gl_vertex3f(float x, float y, float z)
nuclear@2: {
nuclear@2: 	gl_vertex4f(x, y, z, 1.0f);
nuclear@2: }
nuclear@2: 
nuclear@2: void gl_vertex4f(float x, float y, float z, float w)
nuclear@2: {
nuclear@2: 	int i, buffer_full;
nuclear@2: 
nuclear@2: 	if(prim == GL_QUADS && vert_calls % 4 == 3) {
nuclear@2: 		for(i=0; i<2; i++) {
nuclear@2: 			if(aloc != -1) {
nuclear@2: 				attr_arr[num_verts] = attr_arr[num_verts - 3 + i];
nuclear@2: 			}
nuclear@2: 			if(cloc != -1) {
nuclear@2: 				col_arr[num_verts] = col_arr[num_verts - 3 + i];
nuclear@2: 			}
nuclear@2: 			if(tloc != -1) {
nuclear@2: 				texc_arr[num_verts] = texc_arr[num_verts - 3 + i];
nuclear@2: 			}
nuclear@2: 			if(nloc != -1) {
nuclear@2: 				norm_arr[num_verts] = norm_arr[num_verts - 3 + i];
nuclear@2: 			}
nuclear@2: 			vert_arr[num_verts] = vert_arr[num_verts - 3 + i];
nuclear@2: 			num_verts++;
nuclear@2: 		}
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	vert_arr[num_verts].x = x;
nuclear@2: 	vert_arr[num_verts].y = y;
nuclear@2: 	vert_arr[num_verts].z = z;
nuclear@2: 	vert_arr[num_verts].w = w;
nuclear@2: 
nuclear@2: 	if(cloc != -1) {
nuclear@2: 		col_arr[num_verts] = cur_color;
nuclear@2: 	}
nuclear@2: 	if(nloc != -1) {
nuclear@2: 		norm_arr[num_verts] = cur_normal;
nuclear@2: 	}
nuclear@2: 	if(tloc != -1) {
nuclear@2: 		texc_arr[num_verts] = cur_texcoord;
nuclear@2: 	}
nuclear@2: 	if(aloc != -1) {
nuclear@2: 		attr_arr[num_verts] = cur_attrib;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	vert_calls++;
nuclear@2: 	num_verts++;
nuclear@2: 
nuclear@2: 	if(prim == GL_QUADS) {
nuclear@2: 		/* leave space for 6 more worst-case and don't allow flushes mid-quad */
nuclear@2: 		buffer_full = num_verts >= MAX_VERTS - 6 && vert_calls % 4 == 0;
nuclear@2: 	} else {
nuclear@2: 		buffer_full = num_verts >= MAX_VERTS - prim;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	if(buffer_full) {
nuclear@2: 		gl_draw_immediate();
nuclear@3: 		gl_begin(prim);	/* reset everything */
nuclear@2: 	}
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: void gl_normal3f(float x, float y, float z)
nuclear@2: {
nuclear@2: 	cur_normal.x = x;
nuclear@2: 	cur_normal.y = y;
nuclear@2: 	cur_normal.z = z;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: void gl_color3f(float r, float g, float b)
nuclear@2: {
nuclear@2: 	cur_color.x = r;
nuclear@2: 	cur_color.y = g;
nuclear@2: 	cur_color.z = b;
nuclear@2: 	cur_color.w = 1.0f;
nuclear@2: }
nuclear@2: 
nuclear@2: void gl_color4f(float r, float g, float b, float a)
nuclear@2: {
nuclear@2: 	cur_color.x = r;
nuclear@2: 	cur_color.y = g;
nuclear@2: 	cur_color.z = b;
nuclear@2: 	cur_color.w = a;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: void gl_texcoord1f(float s)
nuclear@2: {
nuclear@2: 	cur_texcoord.x = s;
nuclear@2: 	cur_texcoord.y = 0.0f;
nuclear@2: }
nuclear@2: 
nuclear@2: void gl_texcoord2f(float s, float t)
nuclear@2: {
nuclear@2: 	cur_texcoord.x = s;
nuclear@2: 	cur_texcoord.y = t;
nuclear@2: }
nuclear@2: 
nuclear@2: void gl_vertex_attrib2f(int loc, float x, float y)
nuclear@2: {
nuclear@2: 	aloc = loc;
nuclear@2: 	cur_attrib.x = x;
nuclear@2: 	cur_attrib.y = y;
nuclear@2: 	cur_attrib.z = 0.0f;
nuclear@2: 	cur_attrib.w = 1.0f;
nuclear@2: }
nuclear@2: 
nuclear@2: void gl_vertex_attrib3f(int loc, float x, float y, float z)
nuclear@2: {
nuclear@2: 	aloc = loc;
nuclear@2: 	cur_attrib.x = x;
nuclear@2: 	cur_attrib.y = y;
nuclear@2: 	cur_attrib.z = z;
nuclear@2: 	cur_attrib.w = 1.0f;
nuclear@2: }
nuclear@2: 
nuclear@2: void gl_vertex_attrib4f(int loc, float x, float y, float z, float w)
nuclear@2: {
nuclear@2: 	aloc = loc;
nuclear@2: 	cur_attrib.x = x;
nuclear@2: 	cur_attrib.y = y;
nuclear@2: 	cur_attrib.z = z;
nuclear@2: 	cur_attrib.w = w;
nuclear@2: }