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cp template -> lighting

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This commit is contained in:
Josh Holtrop 2011-04-30 19:47:55 -04:00
parent 57f984c92a
commit 4e40f6af5c
5 changed files with 262 additions and 0 deletions
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10
lighting/Makefile Normal file
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export SCONSFLAGS := -Q
all:
@scons
install:
@scons $@
clean:
@scons -c

8
lighting/SConstruct Normal file
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# vim:filetype=python
env = Environment(LIBS = ['GL'])
env.ParseConfig('sdl-config --cflags --libs')
sources = Glob('*.cc')
env.Program('test', sources)

5
lighting/f_shader.glsl Normal file
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void main(void)
{
gl_FragColor = gl_Color;
}

230
lighting/test.cc Normal file
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#define GL_GLEXT_PROTOTYPES
#include <sys/stat.h>
#include <fcntl.h>
#include <SDL/SDL.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <iostream>
using namespace std;
#define WIDTH 800
#define HEIGHT 600
#define STRIDE(a, b) ((unsigned long)(b) - (unsigned long)(a))
#define OFFSET(a, b) ((const GLvoid *)STRIDE((a), (b)))
const GLfloat data[][2][3] = {
{{-1.0, -0.6, 0.0}, {1, 0, 0}},
{{-0.2, -0.6, 0.0}, {0, 1, 0}},
{{-0.6, 0.6, 0.0}, {0, 0, 1}},
{{0.2, -0.6, 0.0}, {1, 0, 0}},
{{1.0, -0.6, 0.0}, {0, 1, 0}},
{{0.6, 0.6, -10.0}, {0, 0, 1}}
};
const GLushort indices[] = {
0, 1, 2, 3, 4, 5
};
GLuint program, vs, fs, data_vbo, index_vbo;
enum Locations {
LOC_POSITION,
LOC_COLOR
};
char * loadFile(const char *fname)
{
struct stat st;
if (stat(fname, &st) != 0)
return NULL;
if (st.st_size <= 0)
return NULL;
char * buff = new char[st.st_size + 1];
int fd = open(fname, O_RDONLY);
read(fd, buff, st.st_size);
close(fd);
buff[st.st_size] = '\0';
return buff;
}
char *getShaderLog(GLuint id)
{
GLint log_length;
glGetShaderiv(id, GL_INFO_LOG_LENGTH, &log_length);
if (log_length > 0)
{
char *log = new char[log_length];
glGetShaderInfoLog(id, log_length, &log_length, log);
return log;
}
return NULL;
}
char *getProgramLog(GLuint id)
{
GLint log_length;
glGetProgramiv(id, GL_INFO_LOG_LENGTH, &log_length);
if (log_length > 0)
{
char *log = new char[log_length];
glGetProgramInfoLog(id, log_length, &log_length, log);
return log;
}
return NULL;
}
GLuint makeShader(GLenum shaderType, const char *fname)
{
GLuint id;
const char *source;
GLint status;
id = glCreateShader(shaderType);
if (id <= 0)
{
cerr << "Error creating shader object" << endl;
goto out;
}
source = loadFile(fname);
if (source == NULL)
{
fprintf(stderr, "Error reading file '%s'\n", fname);
goto cleanup_shader;
}
glShaderSource(id, 1, &source, NULL);
delete[] source;
glCompileShader(id);
glGetShaderiv(id, GL_COMPILE_STATUS, &status);
if (status != GL_TRUE)
{
cerr << "Error compiling shader" << endl;
char *log = getShaderLog(id);
cerr << "Shader Log:" << endl << log << endl;
delete[] log;
goto cleanup_shader;
}
return id;
cleanup_shader:
glDeleteShader(id);
out:
return 0;
}
GLuint makeBuffer(GLenum target, const void *ptr, size_t sz)
{
GLuint id;
glGenBuffers(1, &id);
glBindBuffer(target, id);
glBufferData(target, sz, ptr, GL_STATIC_DRAW);
return id;
}
bool init(int width, int height)
{
glClearColor (0.0, 0.0, 0.0, 0.0);
glEnable(GL_DEPTH_TEST);
glViewport(0, 0, WIDTH, HEIGHT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
float near = 0.1;
float scale = near * 0.577 * 2;
float aspect = (float)width / (float)height;
glFrustum(-aspect * scale, aspect * scale, -scale, scale, near, 1000.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0, 0, -1);
vs = makeShader(GL_VERTEX_SHADER, "v_shader.glsl");
fs = makeShader(GL_FRAGMENT_SHADER, "f_shader.glsl");
if (vs <= 0 || fs <= 0)
{
return false;
}
program = glCreateProgram();
glAttachShader(program, vs);
glAttachShader(program, fs);
glBindAttribLocation(program, LOC_POSITION, "pos");
glBindAttribLocation(program, LOC_COLOR, "color");
glLinkProgram(program);
GLint link_status;
glGetProgramiv(program, GL_LINK_STATUS, &link_status);
if (link_status != GL_TRUE)
{
char *log = getProgramLog(program);
cerr << "Program log:" << endl << log << endl;
delete[] log;
glDeleteShader(vs);
glDeleteShader(fs);
return false;
}
data_vbo = makeBuffer(GL_ARRAY_BUFFER, data, sizeof(data));
index_vbo = makeBuffer(GL_ELEMENT_ARRAY_BUFFER, indices, sizeof(indices));
return true;
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUseProgram(program);
glBindBuffer(GL_ARRAY_BUFFER, data_vbo);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, index_vbo);
glEnableVertexAttribArray(LOC_POSITION);
glEnableVertexAttribArray(LOC_COLOR);
glVertexAttribPointer(LOC_POSITION, 3, GL_FLOAT, GL_FALSE,
STRIDE(&data[0], &data[1]), OFFSET(&data[0], &data[0][0]));
glVertexAttribPointer(LOC_COLOR, 3, GL_FLOAT, GL_FALSE,
STRIDE(&data[0], &data[1]), OFFSET(&data[0], &data[0][1]));
glDrawElements(GL_TRIANGLES, sizeof(indices)/sizeof(indices[0]),
GL_UNSIGNED_SHORT, OFFSET(&indices, &indices[0]));
SDL_GL_SwapBuffers();
}
int main(int argc, char *argv[])
{
if (SDL_Init(SDL_INIT_VIDEO))
{
printf("Failed to initialize SDL!\n");
return 1;
}
atexit(SDL_Quit);
SDL_Surface *screen;
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
if (!(screen = SDL_SetVideoMode(WIDTH, HEIGHT, 16, SDL_OPENGL)))
{
printf("Failed to set video mode!\n");
SDL_Quit();
return 2;
}
SDL_WM_SetCaption(argv[0], argv[0]);
if (!init(WIDTH, HEIGHT))
return 2;
display();
SDL_Event event;
while (SDL_WaitEvent(&event))
{
if (event.type == SDL_QUIT)
break;
else if (event.type == SDL_KEYDOWN)
{
if (event.key.keysym.sym == SDLK_ESCAPE)
break;
}
}
}

9
lighting/v_shader.glsl Normal file
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attribute vec3 pos;
attribute vec3 color;
void main(void)
{
gl_Position = gl_ModelViewProjectionMatrix * vec4(pos, 1);
gl_FrontColor = vec4(color, 1);
}