I am new to shaders, and I am trying to tint a texture to mark status of a enemy.
I am implementing shaders on OpenGL ES 2.0 (Mobile)
The problem is that with this shaders, I see the enemy without change (even if I assign de fragcolor to (1.0, 0 , 0 ,1.0), the real code is commented).
Vertex shader
uniform mat4 u_MVPMatrix; // A constant representing the combined model/view/projection matrix.
uniform mat4 u_MVMatrix; // A constant representing the combined model/view matrix.
attribute vec4 a_Position; // Per-vertex position information we will pass in.
attribute vec3 a_Normal; // Per-vertex normal information we will pass in.
attribute vec2 a_TexCoordinate; // Per-vertex texture coordinate information we will pass in.
varying vec3 v_Position; // This will be passed into the fragment shader.
varying vec3 v_Normal; // This will be passed into the fragment shader.
varying vec2 v_TexCoordinate; // This will be passed into the fragment shader.
// The entry point for our vertex shader.
void main()
{
// Transform the vertex into eye space.
v_Position = vec3(u_MVMatrix * a_Position);
// Pass through the texture coordinate.
v_TexCoordinate = a_TexCoordinate;
// Transform the normal's orientation into eye space.
v_Normal = vec3(u_MVMatrix * vec4(a_Normal, 0.0));
// gl_Position is a special variable used to store the final position.
// Multiply the vertex by the matrix to get the final point in normalized screen coordinates.
gl_Position = u_MVPMatrix * a_Position;
}
Fragment shader
precision mediump float; // Set the default precision to medium. We don't need as high of a
// precision in the fragment shader.
uniform sampler2D u_Texture; // The input texture.
varying vec3 v_Position; // Interpolated position for this fragment.
varying vec3 v_Normal; // Interpolated normal for this fragment.
varying vec2 v_TexCoordinate; // Interpolated texture coordinate per fragment.
// The entry point for our fragment shader.
void main()
{
vec4 texVal = texture2D(u_Texture, v_TexCoordinate);
gl_FragColor = (1.0, 0 , 0 ,1.0);//vec4(texVal.rgb, texVal.a)*(1.0, 0 , 0 ,1.0);
}
