Hello. I’m trying add to ofx plugin shader.
Please tell me how to transfer the image to the shader.
// ! shader id
GLuint Program;
GLuint TEXTURE;
GLint Resolution;
GLuint TDiffuse;
// ! shader log
void shaderLog(unsigned int shader)
{
int infologLen = 0;
int charsWritten = 0;
char *infoLog;
glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &infologLen);
if (infologLen > 1)
{
infoLog = new char[infologLen];
if (infoLog == NULL)
{
std::cout << "ERROR: Could not allocate InfoLog buffer
";
exit(1);
}
glGetShaderInfoLog(shader, infologLen, &charsWritten, infoLog);
std::cout << "InfoLog: " << infoLog << "
";
delete[] infoLog;
}
}
// ! init ogl
void initGL()
{
glClearColor(0, 0, 0, 0);
}
#define STR(x) #x
#define STRINGIFY(x) STR(x)
// ! shaders init
void initShader()
{
const char* msaaSource =
STRINGIFY(
uniform sampler2D tDiffuse;
uniform vec2 resolution;
varying vec2 vUv;
const float FXAA_REDUCE_MIN = 1.0 / 128.0;
const float FXAA_REDUCE_MUL = 1.0 / 8.0;
const float FXAA_SPAN_MAX = 8.0;
void main() {
vec3 rgbNW = texture2D(tDiffuse, (gl_FragCoord.xy + vec2(-1.0, -1.0)) * resolution).xyz;
vec3 rgbNE = texture2D(tDiffuse, (gl_FragCoord.xy + vec2(1.0, -1.0)) * resolution).xyz;
vec3 rgbSW = texture2D(tDiffuse, (gl_FragCoord.xy + vec2(-1.0, 1.0)) * resolution).xyz;
vec3 rgbSE = texture2D(tDiffuse, (gl_FragCoord.xy + vec2(1.0, 1.0)) * resolution).xyz;
vec4 rgbaM = texture2D(tDiffuse, gl_FragCoord.xy * resolution);
vec3 rgbM = rgbaM.xyz;
float opacity = rgbaM.w;
vec3 luma = vec3(0.299, 0.587, 0.114);
float lumaNW = dot(rgbNW, luma);
float lumaNE = dot(rgbNE, luma);
float lumaSW = dot(rgbSW, luma);
float lumaSE = dot(rgbSE, luma);
float lumaM = dot(rgbM, luma);
float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE)));
float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE)));
vec2 dir;
dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE));
dir.y = ((lumaNW + lumaSW) - (lumaNE + lumaSE));
float dirReduce = max((lumaNW + lumaNE + lumaSW + lumaSE) * (0.25 * FXAA_REDUCE_MUL), FXAA_REDUCE_MIN);
float rcpDirMin = 1.0 / (min(abs(dir.x), abs(dir.y)) + dirReduce);
dir = min(vec2(FXAA_SPAN_MAX, FXAA_SPAN_MAX),
max(vec2(-FXAA_SPAN_MAX, -FXAA_SPAN_MAX),
dir * rcpDirMin)) * resolution;
vec3 rgbA = 0.5 * (
texture2D(tDiffuse, gl_FragCoord.xy * resolution + dir * (1.0 / 3.0 - 0.5)).xyz +
texture2D(tDiffuse, gl_FragCoord.xy * resolution + dir * (2.0 / 3.0 - 0.5)).xyz);
vec3 rgbB = rgbA * 0.5 + 0.25 * (
texture2D(tDiffuse, gl_FragCoord.xy * resolution + dir * -0.5).xyz +
texture2D(tDiffuse, gl_FragCoord.xy * resolution + dir * 0.5).xyz);
float lumaB = dot(rgbB, luma);
if ((lumaB < lumaMin) || (lumaB > lumaMax)) {
gl_FragColor = vec4(rgbA, opacity);
}
else {
gl_FragColor = vec4(rgbB, opacity);
}
}
);
// ! var for shaers ids
GLuint msaaShader;
// ! create fragment shader
msaaShader = glCreateShader(GL_FRAGMENT_SHADER); //GL_SAMPLER_2D
// ! transmit shader source
glShaderSource(msaaShader, 1, &msaaSource, NULL);
// ! complie shader
glCompileShader(msaaShader);
std::cout << "sampler2d shader
";
shaderLog(msaaShader);
// ! create program and attach shaders
Program = glCreateProgram();
glAttachShader(Program, msaaShader);
// ! link shader program
glLinkProgram(Program);
// ! check link
int link_ok;
glGetProgramiv(Program, GL_LINK_STATUS, &link_ok);
if (!link_ok)
{
std::cout << "error attach shaders
";
return;
}
// just for check
int total = -1;
glGetProgramiv(Program, GL_ACTIVE_UNIFORMS, &total);
std::cout << "total: " << total;
for (int i = 0; i < total; ++i) {
int name_len = -1, num = -1;
GLenum type = GL_ZERO;
char name[100];
glGetActiveUniform(Program, GLuint(i), sizeof(name) - 1,
&name_len, &num, &type, name);
name[name_len] = 0;
GLuint location = glGetUniformLocation(Program, name);
}
// get params ids
const char* tDiffuse_name = "tDiffuse";
TDiffuse = glGetUniformLocation(Program, tDiffuse_name);
if (TDiffuse == -1)
{
std::cout << "could not bind tDiffuse " << tDiffuse_name << std::endl;
return;
}
const char* resolution_name = "resolution";
Resolution = glGetUniformLocation(Program, resolution_name);
if (Resolution == -1)
{
std::cout << "could not bind resolution " << resolution_name << std::endl;
return;
}
checkOpenGLerror();
}
//! render
void render()
{
if (!flag)
{
flag = true;
char fakeParam[] = "fake";
char *fakeargv[] = { fakeParam, NULL };
int fakeargc = 1;
glutInit(&fakeargc, fakeargv);
glewInit();
//initGL();
initShader();
}
glClear(GL_COLOR_BUFFER_BIT);
glUseProgram(Program);
// set resolution
glUniform2f(Resolution, 1.f, 1.f);
//glActiveTexture(GL_TEXTURE0);
//glBindTexture(GL_TEXTURE_2D, texture0);
//glUniform1i(TDiffuse, 0);
//glUniform1i(TDiffuse, 0); /// <== ?????
// ! turn off shader program
glUseProgram(0);
checkOpenGLerror();
}
a place where I need help:
...
glUseProgram(Program);
// set resolution
glUniform2f(Resolution, 1.f, 1.f);
// set sampler2D
//glActiveTexture(GL_TEXTURE0);
//glBindTexture(GL_TEXTURE_2D, texture0);
//glUniform1i(TDiffuse, 0);
//glUniform1i(TDiffuse, 0); /// <== ?????
// ! turn off shader program
glUseProgram(0);
checkOpenGLerror();
I testet simple shaders like this:
const char* vsSource =
"attribute vec2 coord;
"
"void main() {
"
" gl_Position = vec4(coord, 0.0, 1.0);
"
"}
";
const char* fsSource =
"uniform vec4 color;
"
"void main() {
"
" gl_FragColor = color;
"
"}
";
it’s work ok.
for render i use this code:
glClear(GL_COLOR_BUFFER_BIT);
glUseProgram(Program);
static float red[4] = {1.0f, 0.0f, 0.0f, 1.0f};
glUniform4fv(Unif_color, 1, red);
glEnableVertexAttribArray(Attrib_vertex);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glVertexAttribPointer(Attrib_vertex, 2, GL_FLOAT, GL_FALSE, 0, 0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glDrawArrays(GL_TRIANGLES, 0, sizeof (vertex));
glDisableVertexAttribArray(Attrib_vertex);
glUseProgram(0);
checkOpenGLerror();
if needed, can provide full plugin code