master
Alessandro Mauri 2 years ago
parent 2c9b6e06fa
commit e0e89d0f2b
Signed by: alema
GPG Key ID: 2B7BF9531FF03BE8
  1. BIN
      opengl-ren/charmap.ff
  2. BIN
      opengl-ren/charmap.png
  3. 6
      opengl-ren/fragment.glsl
  4. 137
      opengl-ren/main.c
  5. 3
      opengl-ren/vertex.glsl

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Width:  |  Height:  |  Size: 1.0 KiB

@ -1,10 +1,12 @@
#version 330 #version 330
flat in vec4 out_color; flat in vec4 out_color;
in vec2 texture_coord;
uniform sampler2D texture_sampler;
out vec4 color; out vec4 color;
void main() void main()
{ {
// set the color for each vertex to white color = texture(texture_sampler, texture_coord) + out_color;
color = out_color;
} }

@ -1,6 +1,8 @@
#include <stddef.h>
#define _POSIX_C_SOURCE 200809l #define _POSIX_C_SOURCE 200809l
#include <sys/mman.h> #include <sys/mman.h>
#include <arpa/inet.h>
#include <stdlib.h> #include <stdlib.h>
#include <stdio.h> #include <stdio.h>
@ -21,16 +23,19 @@
const int vertindex = 0; const int vertindex = 0;
const int colindex = 1; const int colindex = 1;
const int textindex = 2;
struct { struct {
SDL_Window *w; SDL_Window *w;
SDL_GLContext *gl; SDL_GLContext *gl;
GLuint gl_vertbuffer; GLuint gl_vertbuffer;
GLuint gl_program; GLuint gl_program;
GLuint font_texture;
} ren = {0}; } ren = {0};
typedef struct PACKED { typedef struct PACKED {
GLfloat x, y; union { GLfloat x, u; };
union { GLfloat y, v; };
} vec2; } vec2;
typedef struct PACKED { typedef struct PACKED {
@ -43,7 +48,8 @@ typedef struct PACKED {
// a vertex has a position and a color // a vertex has a position and a color
struct PACKED vertex { struct PACKED vertex {
vec2 pos; vec2 pos;
vec4 col; vec2 texture;
vec4 color;
}; };
@ -62,6 +68,17 @@ int w_width(SDL_Window *);
//}; //};
// this just descrives a farbfeld image
// https://tools.suckless.org/farbfeld/
struct PACKED _ff {
uint8_t magic[8];
uint32_t w, h;
uint64_t bytes[];
};
const int gw = 7, gh = 9;
unsigned int fw, fh;
struct { struct {
struct vertex *v; struct vertex *v;
int size, idx; int size, idx;
@ -78,7 +95,7 @@ void grow_stack(int step)
} }
int vstack_push_quad(int x, int y, int w, int h, vec4 color) int vstack_push_quad_c(int x, int y, int w, int h, vec4 color)
{ {
if (vstack.idx <= vstack.size) if (vstack.idx <= vstack.size)
grow_stack(6); grow_stack(6);
@ -106,18 +123,64 @@ int vstack_push_quad(int x, int y, int w, int h, vec4 color)
y4 = y3 = (float)(hh - y) / hh; y4 = y3 = (float)(hh - y) / hh;
y1 = y2 = (float)(hh - y-h) / hh; y1 = y2 = (float)(hh - y-h) / hh;
printf("x1=%.3f x2=%.3f, y1=%.3f y4=%.3f\n", x1, x2, y1, y4); vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x1, .pos.y=y1, .color=color };
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x2, .pos.y=y2, .color=color };
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x3, .pos.y=y3, .color=color };
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x1, .pos.y=y1, .color=color };
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x3, .pos.y=y3, .color=color };
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x4, .pos.y=y4, .color=color };
return 0;
}
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x1, .pos.y=y1, .col=color }; int vstack_push_quad_t(int x, int y, int w, int h, int u, int v)
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x2, .pos.y=y2, .col=color }; {
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x3, .pos.y=y3, .col=color }; if (vstack.idx <= vstack.size)
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x1, .pos.y=y1, .col=color }; grow_stack(6);
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x3, .pos.y=y3, .col=color };
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x4, .pos.y=y4, .col=color }; // x4,y4 x3,y3
// +-------------+
// |(x,y) /|
// | / |
// | 2 / |
// | / |
// | / |
// | / 1 |
// |/ |
// +-------------+
// x1,y1 x2,y2
int hw = w_width(ren.w)/2;
int hh = w_width(ren.w)/2;
float x1, x2, x3, x4;
float y1, y2, y3, y4;
x1 = x4 = (float)(x - hw) / hw;
x2 = x3 = (float)(x+w - hw) / hw;
y1 = y2 = (float)(hh - y-h) / hh;
y3 = y4 = (float)(hh - y) / hh;
float u1, u2, u3, u4;
float v1, v2, v3, v4;
u1 = u4 = (float)(u) / fw;
u2 = u3 = (float)(u+gw) / fw;
v1 = v2 = (float)(v+gh) / fh;
v3 = v4 = (float)(v) / fh;
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x1, .pos.y=y1, .texture.x=u1, .texture.y=v1 };
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x2, .pos.y=y2, .texture.x=u2, .texture.y=v2 };
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x3, .pos.y=y3, .texture.x=u3, .texture.y=v3 };
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x1, .pos.y=y1, .texture.x=u1, .texture.y=v1 };
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x3, .pos.y=y3, .texture.x=u3, .texture.y=v3 };
vstack.v[vstack.idx++] = (struct vertex){ .pos.x=x4, .pos.y=y4, .texture.x=u4, .texture.y=v4 };
return 0; return 0;
} }
void vstack_clear(void) void vstack_clear(void)
{ {
vstack.idx = 0; vstack.idx = 0;
@ -149,7 +212,10 @@ void ren_initvertbuffer()
// always referred to by index and not by pointer or other manners, indices // always referred to by index and not by pointer or other manners, indices
// go from 0 to 15 // go from 0 to 15
glEnableVertexAttribArray(colindex); glEnableVertexAttribArray(colindex);
glVertexAttribPointer(colindex, 4, GL_FLOAT, GL_FALSE, sizeof(struct vertex), (void*)sizeof(vec2)); glVertexAttribPointer(colindex, 4, GL_FLOAT, GL_FALSE, sizeof(struct vertex), (void*)(2*sizeof(vec2)));
// texture uv data
glEnableVertexAttribArray(textindex);
glVertexAttribPointer(textindex, 2, GL_FLOAT, GL_FALSE, sizeof(struct vertex), (void*)sizeof(vec2));
// reset the object bind so not to create errors // reset the object bind so not to create errors
glBindBuffer(GL_ARRAY_BUFFER, 0); glBindBuffer(GL_ARRAY_BUFFER, 0);
} }
@ -298,6 +364,46 @@ int w_width(SDL_Window *win)
} }
void import_font(const char *path)
{
const char *map;
int size;
const struct _ff *img;
map_file(&map, &size, path);
img = (const struct _ff *)map;
fw = ntohl(img->w);
fh = ntohl(img->h);
glGenTextures(1, &ren.font_texture);
glBindTexture(GL_TEXTURE_2D, ren.font_texture);
// farbfeld image
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, fw, fh, 0, GL_RGBA, GL_UNSIGNED_SHORT, img->bytes);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
munmap((void *)map, size);
}
void push_text(int x, int y, const char *s)
{
for (; *s; s++) {
int u, v;
int idx = *s - ' ';
u = idx % (fw / gw);
v = (idx / (fw / gw)) % (fh / gh);
vstack_push_quad_t(x, y, gw*2, gh*2, u*gw, v*gh);
x += gw*2;
if (*s == '\n')
y += gh;
}
}
int main (void) int main (void)
{ {
SDL_Init(SDL_INIT_VIDEO | SDL_INIT_EVENTS); SDL_Init(SDL_INIT_VIDEO | SDL_INIT_EVENTS);
@ -328,11 +434,14 @@ int main (void)
err(-1, "Failed to initialize GLEW: %s", glewGetErrorString(glew_err)); err(-1, "Failed to initialize GLEW: %s", glewGetErrorString(glew_err));
ren_initshaders(); ren_initshaders();
import_font("./charmap.ff");
vec4 magenta = {.r=1.0, .g=0.0, .b=1.0, .a=1.0}; vec4 magenta = {.r=1.0, .g=0.0, .b=1.0, .a=1.0};
vstack_push_quad(0, 0, 100, 100, magenta); vstack_push_quad_c(0, 0, 100, 100, magenta);
vstack_push_quad(200, 0, 10, 10, magenta); vstack_push_quad_c(200, 0, 10, 10, magenta);
vstack_push_quad(10, 150, 100, 100, magenta); vstack_push_quad_c(10, 150, 100, 100, magenta);
push_text(250, 250, "ò Ciao Victoria <3");
ren_initvertbuffer(); ren_initvertbuffer();
// event loop and drawing // event loop and drawing

@ -3,12 +3,15 @@
// use the input ("in") vertices from index zero // use the input ("in") vertices from index zero
layout(location = 0) in vec2 position; layout(location = 0) in vec2 position;
layout(location = 1) in vec4 color; layout(location = 1) in vec4 color;
layout(location = 2) in vec2 uv;
flat out vec4 out_color; flat out vec4 out_color;
out vec2 texture_coord;
void main() void main()
{ {
// simply copy teh output position // simply copy teh output position
gl_Position = vec4(position.x, position.y, 0.0f, 1.0f); gl_Position = vec4(position.x, position.y, 0.0f, 1.0f);
out_color = color; out_color = color;
texture_coord = uv;
} }
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