gem-graph-client/include/graphics.h

387 lines
11 KiB
C

/*
* Gem-graph OpenGL experiments
*
* Desc: OpenGL utils header
*
* Copyright (C) 2023 Arthur Menges <arthur.menges@a-lec.org>
* Copyright (C) 2023 Adrien Bourmault <neox@a-lec.org>
* Copyright (C) 2023 Jean Sirmai <jean@a-lec.org>
*
* This file is part of Gem-graph.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "base.h"
#include <unistd.h>
#include <stdbool.h>
#include <epoxy/gl.h>
#include <GL/glu.h>
#include <GL/glext.h>
#define VERTEX_SHADER_FILE "src/graphics/shaders/shader.vert"
#define FRAG_SHADER_FILE "src/graphics/shaders/shader.frag"
#define GL_TARGET_MAJOR_VERSION 0
#define GL_TARGET_MINOR_VERSION 4
/*
* Structure describing a gl_area and its parameters, used to create a table
* of Gem-graph client current gl_areas
*/
struct graphic_stack_t {
int id;
int mode;
float rotation_angles[N_AXIS]; // Rotation angles on each axis
GLuint vao; // init_buffers
GLuint position_buffer; // shutdown, draw
GLuint color_buffer; // shutdown, draw
GLuint program; // shutdown, init_shaders, draw
GLuint m; // init_shaders, draw
GLuint v; // init_shaders, draw
GLuint p; // init_shaders, draw
struct arrow_t *arrows_ptr;
long arrows_nb;
GLfloat *buffer_vertex_origin;
GLfloat *buffer_colors_origin;
GLuint *buffer_lines_origin;
GLuint *buffer_plans_origin;
long buffer_vertex_size;
long buffer_colors_size;
long buffer_lines_size;
long buffer_plans_size;
long buffer_vertex_0_arrow;
long buffer_colors_0_arrow;
long buffer_lines_0_arrow;
long buffer_plans_0_arrow;
};
/*
* Dynamic array of ptrs to dynamically allocated gl_area_entry
*/
extern struct graphic_stack_t *graphic_stack;
/*
* Initializes a gl_area
*
* @param gl_area, ptr to the gl_area widget
*
* @return true if initialized
*/
int graphics_init(void);
/*
* Draws the current buffer to a gl_area
*
* @param gl_area, ptr to the gl_area widget
*
* @return void
*/
void graphics_draw(const int stack_id);
/*
* Shutdowns a gl_area
*
* @param gl_area, ptr to the gl_area widget
*
* @return true if success
*/
bool graphics_shutdown(const int stack_id);
/*
* Initializes the shaders of a gl_area and link them to a program
*
* @param gl_area, ptr to the gl_area widget
*
* @return true if initialized
*/
bool graphics_init_shaders(const int stack_id);
/* Initializes the buffer of a gl_area
* Calls according to the user preferences
* @param gl_area, ptr to the gl_area widget
* @return void
*/
void graphics_init_buffers(const int stack_id);
/*
* Draws a vertex (x, y, z)
* if (console) prints (x, y, z) values to console
*
* @param GLfloat x, GLfloat y, GLfloat z
*
* @return void
*/
void graphics_draw_vertex (const int stack_id,
GLfloat x,
GLfloat y,
GLfloat z);
/*
* Draws the color (r, g, b) associated to a vertex
* if (console) prints (r, g, b) values to console
*
* @param GLfloat r, GLfloat g, GLfloat b
*
* @return void
*/
void graphics_draw_color (const int stack_id, GLfloat r, GLfloat g, GLfloat b);
/*
* Writes values to describe a line from a to b into the line buffer
*
* @param coords GLuint (a,b)
*
* @return void
*/
void graphics_draw_line (const int stack_id, GLuint a, GLuint b);
/*
* Writes values to describe an (a,b,c) plan (triangle) into the plan buffer
*
* @param coords GLuint (a,b,c)
*
* @return void
*/
void graphics_draw_plan (const int stack_id, GLuint a, GLuint b, GLuint c);
/*
* Initializes an identity matrix
*
* @param res, target ptr
*
* @return void
*/
static inline void compute_i(float *res)
{
/* initialize to the identity matrix */
res[0] = 1.f; res[4] = 0.f; res[8] = 0.f; res[12] = 0.f;
res[1] = 0.f; res[5] = 1.f; res[9] = 0.f; res[13] = 0.f;
res[2] = 0.f; res[6] = 0.f; res[10] = 1.f; res[14] = 0.f;
res[3] = 0.f; res[7] = 0.f; res[11] = 0.f; res[15] = 1.f;
}
/*
* Computes the projection matrix
*
* @param res, target ptr
* phi, XXX
* theta, XXX
* psi, XXX
*
* @return void
*/
static inline void compute_mvp(float *res, float phi, float theta, float psi)
{
float x = phi *(G_PI / 180.f);
float y = theta *(G_PI / 180.f);
float z = psi *(G_PI / 180.f);
float c1 = cosf(x), s1 = sinf(x);
float c2 = cosf(y), s2 = sinf(y);
float c3 = cosf(z), s3 = sinf(z);
float c3c2 = c3 * c2;
float s3c1 = s3 * c1;
float c3s2s1 = c3 * s2 * s1;
float s3s1 = s3 * s1;
float c3s2c1 = c3 * s2 * c1;
float s3c2 = s3 * c2;
float c3c1 = c3 * c1;
float s3s2s1 = s3 * s2 * s1;
float c3s1 = c3 * s1;
float s3s2c1 = s3 * s2 * c1;
float c2s1 = c2 * s1;
float c2c1 = c2 * c1;
compute_i(res);
/* apply all three rotations using the three matrices:
*
* ⎡ c3 s3 0 ⎤ ⎡ c2 0 -s2 ⎤ ⎡ 1 0 0 ⎤
* ⎢ -s3 c3 0 ⎥ ⎢ 0 1 0 ⎥ ⎢ 0 c1 s1 ⎥
* ⎣ 0 0 1 ⎦ ⎣ s2 0 c2 ⎦ ⎣ 0 -s1 c1 ⎦
*/
res[0] = c3c2; res[4] = s3c1 + c3s2s1; res[8] = s3s1 - c3s2c1; res[12] = 0.f;
res[1] = -s3c2; res[5] = c3c1 - s3s2s1; res[9] = c3s1 + s3s2c1; res[13] = 0.f;
res[2] = s2; res[6] = -c2s1; res[10] = c2c1; res[14] = 0.f;
res[3] = 0.f; res[7] = 0.f; res[11] = 0.f; res[15] = 1.f;
}
/*
* Created and compile a shader
*
* @param type, shader type
* src, source code of shader
*
* @return shader id
*/
static inline GLuint create_shader(const int stack_id, int type, const char *src)
{
GLuint shader;
int status;
shader = glCreateShader(type);
glShaderSource(shader, 1, &src, NULL);
glCompileShader(shader);
glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
if(status == GL_FALSE) {
int log_len;
char *buffer;
glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &log_len);
buffer = g_malloc(log_len + 1);
assert (buffer);
glGetShaderInfoLog(shader, log_len, NULL, buffer);
g_warning("Compile failure in %s shader:\n%s",
type == GL_VERTEX_SHADER ? "vertex" : "fragment",
buffer);
g_free(buffer);
glDeleteShader(shader);
return 0;
}
return shader;
}
static inline void print_stack(int stack_id)
{
static int n = 0;
printf("\n[n=%d]***************", n);
printf("id = %d\tmode = %d\n",
graphic_stack[stack_id].id,
graphic_stack[stack_id].mode);
printf("rotation_angles = ");
for (int i = 0; i < N_AXIS; i++) {
printf("%f\t", graphic_stack[stack_id].rotation_angles[i]); // Rotation angles on each axis
}
printf("\n");
printf("vao = %d\n", graphic_stack[stack_id].vao);
printf("position_buffer = %d\n", graphic_stack[stack_id].position_buffer);
printf("color_buffer = %d\n", graphic_stack[stack_id].color_buffer);
printf("program = %d\n", graphic_stack[stack_id].program);
printf("m = %d\n", graphic_stack[stack_id].m);
printf("v = %d\n", graphic_stack[stack_id].v);
printf("p = %d\n", graphic_stack[stack_id].p);
printf("arrows_ptr = %p\n", graphic_stack[stack_id].arrows_ptr);
printf("arrows_nb = %ld\n", graphic_stack[stack_id].arrows_nb);
printf("buffer_vertex_origin = %p\n", graphic_stack[stack_id].buffer_vertex_origin);
printf("buffer_colors_origin = %p\n", graphic_stack[stack_id].buffer_colors_origin);
printf("buffer_lines_origin = %p\n", graphic_stack[stack_id].buffer_lines_origin);
printf("buffer_plans_origin = %p\n", graphic_stack[stack_id].buffer_plans_origin);
printf("buffer_vertex_size = %ld\n", graphic_stack[stack_id].buffer_vertex_size);
printf("buffer_colors_size = %ld\n", graphic_stack[stack_id].buffer_colors_size);
printf("buffer_lines_size = %ld\n", graphic_stack[stack_id].buffer_lines_size);
printf("buffer_plans_size = %ld\n", graphic_stack[stack_id].buffer_plans_size);
printf("buffer_vertex_0_arrow = %p\n", graphic_stack[stack_id].buffer_vertex_0_arrow);
printf("buffer_colors_0_arrow = %p\n", graphic_stack[stack_id].buffer_colors_0_arrow);
printf("buffer_lines_0_arrow = %p\n", graphic_stack[stack_id].buffer_lines_0_arrow);
printf("buffer_plans_0_arrow = %p\n", graphic_stack[stack_id].buffer_plans_0_arrow);
printf("********************\n");
n++;
}
/*** TEST ***/
void main_test_graphics (const int stack_id);
/*
* Structure describing an arrow
*/
struct arrow_t {
GLuint load;
GLuint site;
GLuint x;
GLuint y;
GLuint z;
};
int draw_one_arrow_vertex (const int stack_id,
int space_X,
int space_Y,
int space_Z,
int weight,
int site,
int x,
int y,
int z);
int draw_one_arrow_line(const int stack_id,
int offset_vertex);
/*
* Writes grid ridges to vertex and color buffers
*
* @param coords long (x,y,z), step_x, step_y, step_z
*
* @return void
*/
int draw_space_ridges_vertex (const int stack_id,
long offset_vertex,
long x,
long y,
long z);
int draw_space_ridges_lines (const int stack_id);
/*
* Writes grid lines on space faces
*
* @param coords long (x,y,z)
*
* @return void
*/
long draw_grids_on_space_faces_vertex (const int stack_id,
long x,
long y,
long z);
long draw_grids_on_space_faces_lines (const int stack_id,
long offset_vertex,
long x,
long y,
long z);
int set_arrow (int stack_id,
int arrows_nb,
int space_X,
int space_Y,
int space_Z,
int requested_weight,
int site,
int arrow_x,
int arrow_y,
int arrow_z);