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remove rotating cube demo; add TextShader class

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This commit is contained in:
Josh Holtrop 2018-01-23 14:49:36 -05:00
parent d776f1a209
commit 27e16bc568
7 changed files with 109 additions and 182 deletions
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36
cube.f.glsl
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@ -1,36 +0,0 @@
uniform vec4 ambient, specular;
uniform float shininess;
uniform sampler2D tex;
varying vec3 pos_i;
varying vec3 normal_i;
varying vec2 tex_coord_i;
void main(void)
{
vec3 n, lightDir;
vec4 color;
float NdotL, RdotEye;
lightDir = normalize(vec3(-0.1, 0, -0.9));
vec4 texture_color = texture2D(tex, tex_coord_i);
color = texture_color * ambient; /* ambient light */
n = normalize(normal_i);
NdotL = dot(n, -lightDir);
if (NdotL > 0.0)
{
/* diffuse component */
color += texture_color * NdotL;
/* specular component */
RdotEye = dot(normalize(-pos_i), normalize(reflect(-lightDir, n)));
if (RdotEye > 0.0)
{
color += clamp(specular * pow(RdotEye, shininess), 0.0, 1.0);
}
}
gl_FragColor = color;
}

19
cube.v.glsl
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@ -1,19 +0,0 @@
uniform mat4 projection;
uniform mat4 modelview;
attribute vec3 pos;
attribute vec3 normal;
attribute vec2 tex_coord;
varying vec3 pos_i;
varying vec3 normal_i;
varying vec2 tex_coord_i;
void main(void)
{
gl_Position = projection * modelview * vec4(pos, 1);
pos_i = gl_Position.xyz;
tex_coord_i = tex_coord;
normal_i = (modelview * vec4(normal, 0)).xyz;
}

14
src/TextShader.cc Normal file
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@ -0,0 +1,14 @@
#include "TextShader.h"
TextShader::TextShader()
{
m_program = glcxx::Program::create(
glcxx::Shader::create_from_file(GL_VERTEX_SHADER, "text.v.glsl"),
glcxx::Shader::create_from_file(GL_FRAGMENT_SHADER, "text.f.glsl"),
"coords", 0);
m_uniforms.viewport_size = m_program->get_uniform_location("viewport_size");
m_uniforms.texture = m_program->get_uniform_location("texture");
m_uniforms.color = m_program->get_uniform_location("color");
m_uniforms.position = m_program->get_uniform_location("position");
}

46
src/TextShader.h Normal file
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@ -0,0 +1,46 @@
#ifndef TEXTSHADER_H
#define TEXTSHADER_H
#include "glcxx.hpp"
#include <memory>
class TextShader
{
public:
TextShader();
void use() { m_program->use(); }
void set_viewport_size(int width, int height)
{
glUniform2i(m_uniforms.viewport_size, width, height);
}
void set_texture(int texture)
{
glUniform1i(m_uniforms.texture, texture);
}
void set_color(float r, float g, float b, float a)
{
glUniform4f(m_uniforms.color, r, g, b, a);
}
void set_position(int x, int y)
{
glUniform2i(m_uniforms.position, x, y);
}
protected:
std::shared_ptr<glcxx::Program> m_program;
struct
{
GLint viewport_size;
GLint texture;
GLint color;
GLint position;
} m_uniforms;
};
#endif

134
src/main.cc
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@ -3,27 +3,11 @@
#include "glcxx.hpp"
#include "GL3/gl3w.h"
#include <iostream>
#include "glm/glm.hpp"
#include "glm/gtc/matrix_transform.hpp"
#include "TextShader.h"
using namespace std;
std::shared_ptr<glcxx::Program> program;
std::shared_ptr<glcxx::Buffer> cube_buffer;
std::shared_ptr<glcxx::Array> cube_array;
static struct
{
GLint ambient;
GLint specular;
GLint shininess;
GLint tex;
GLint projection;
GLint modelview;
} uniforms;
glm::mat4 modelview;
glm::mat4 projection;
std::shared_ptr<glcxx::Texture> texture;
GLubyte texture_data[16][16][4];
std::shared_ptr<TextShader> text_shader;
#define WIDTH 800
#define HEIGHT 800
@ -31,7 +15,6 @@ GLubyte texture_data[16][16][4];
bool init(void)
{
glClearColor (0.0, 0.0, 0.0, 0.0);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
#if 0
glEnable(GL_BLEND);
@ -40,63 +23,10 @@ bool init(void)
glViewport(0, 0, WIDTH, HEIGHT);
try
{
program = glcxx::Program::create(
glcxx::Shader::create_from_file(GL_VERTEX_SHADER, "cube.v.glsl"),
glcxx::Shader::create_from_file(GL_FRAGMENT_SHADER, "cube.f.glsl"),
"position", 0,
"normal", 1,
"tex_coord", 2);
uniforms.ambient = program->get_uniform_location("ambient");
uniforms.specular = program->get_uniform_location("specular");
uniforms.shininess = program->get_uniform_location("shininess");
uniforms.tex = program->get_uniform_location("tex");
uniforms.projection = program->get_uniform_location("projection");
uniforms.modelview = program->get_uniform_location("modelview");
cube_buffer = glcxx::Buffer::create(GL_ARRAY_BUFFER, GL_STATIC_DRAW,
{-1, -1, 1, 0, 0, 1, 0, 0,
1, -1, 1, 0, 0, 1, 1, 0,
1, 1, 1, 0, 0, 1, 1, 1,
-1, 1, 1, 0, 0, 1, 0, 1});
cube_array = glcxx::Array::create();
cube_array->bind();
cube_buffer->bind();
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glEnableVertexAttribArray(2);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), NULL);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (void *)(3 * sizeof(GLfloat)));
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (void *)(6 * sizeof(GLfloat)));
projection = glm::perspective((float)(60.0 * M_PI / 180.0), (float)WIDTH / (float)HEIGHT, 0.1f, 1000.0f);
for (int i = 0; i < 16; i++)
{
for (int j = 0; j < 16; j++)
{
if (((j / 2) & 1) == ((i / 2) & 1))
{
texture_data[i][j][0] = 255;
texture_data[i][j][1] = 255;
texture_data[i][j][2] = 255;
texture_data[i][j][3] = 255;
}
else
{
texture_data[i][j][0] = 100;
texture_data[i][j][1] = 100;
texture_data[i][j][2] = 100;
texture_data[i][j][3] = 100;
}
}
}
texture = glcxx::Texture::create();
glActiveTexture(GL_TEXTURE0);
texture->bind(GL_TEXTURE_2D);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 16, 16, 0, GL_RGBA, GL_UNSIGNED_BYTE, &texture_data[0][0][0]);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
text_shader = std::make_shared<TextShader>();
text_shader->use();
text_shader->set_texture(0);
text_shader->set_viewport_size(WIDTH, HEIGHT);
}
catch (glcxx::Error & e)
{
@ -106,59 +36,9 @@ bool init(void)
return true;
}
static void draw_cube()
{
static const struct
{
int counts;
float axis[3];
} rotations[] = {
{0, {0, 0, 0}},
{1, {1, 0, 0}},
{2, {1, 0, 0}},
{3, {1, 0, 0}},
{1, {0, 1, 0}},
{3, {0, 1, 0}},
};
glm::mat4 modelview_backup = modelview;
program->use();
cube_array->bind();
glUniform4f(uniforms.ambient, 0.2, 0.2, 0.2, 0.2);
glUniform4f(uniforms.specular, 1.0, 1.0, 1.0, 1.0);
glUniform1f(uniforms.shininess, 150.0);
glUniform1i(uniforms.tex, 0);
glUniformMatrix4fv(uniforms.projection, 1, GL_FALSE, &projection[0][0]);
for (unsigned int i = 0; i < sizeof(rotations) / sizeof(rotations[0]); i++)
{
if (rotations[i].counts > 0)
{
modelview = glm::rotate(modelview_backup,
(float)(M_PI / 2.0 * rotations[i].counts),
glm::vec3(rotations[i].axis[0],
rotations[i].axis[1],
rotations[i].axis[2]));
}
glUniformMatrix4fv(uniforms.modelview, 1, GL_FALSE, &modelview[0][0]);
glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
}
modelview = modelview_backup;
}
void display(SDL_Window * window)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
modelview = glm::lookAt(glm::vec3(-1, -8, 7),
glm::vec3(0, 0, 0),
glm::vec3(0, 0, 1));
modelview = glm::rotate(modelview, (float)(SDL_GetTicks() / 1000.0), glm::vec3(0, 0, 1));
modelview = glm::translate(modelview, glm::vec3(3, 0, 0));
draw_cube();
glClear(GL_COLOR_BUFFER_BIT);
SDL_GL_SwapWindow(window);
}

15
text.f.glsl Normal file
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@ -0,0 +1,15 @@
#version 130
/* Texture coordinate: s, t */
in vec2 texture_coord_v;
/* Texture unit */
uniform sampler2D texture;
uniform vec4 color;
out vec4 frag_color;
void main(void)
{
frag_color = vec4(1, 1, 1, texture2D(texture, texture_coord_v).a) * color;
}

27
text.v.glsl Normal file
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@ -0,0 +1,27 @@
#version 130
/* Viewport width and height */
uniform ivec2 viewport_size;
/* Position of lower left corner of glyph */
uniform ivec2 position;
/* Vertex coordinates: x, y, s, t */
in vec4 coords;
/* Output texture coordinate: s, t */
out vec2 texture_coord_v;
/**
* Map coordinates such that:
* (0 .. viewport_size.[xy]) => (-1.0 .. 1.0)
*/
vec2 map_to_screen(vec2 position)
{
return 2.0 * position / viewport_size - 1.0;
}
void main(void)
{
gl_Position = vec4(map_to_screen(vec2(position) + coords.xy), 0, 1);
texture_coord_v = coords.zw;
}