RaindropViewer/Assets/StreamingAssets/shader_data/water.vert

varying vec4 refrCoords; 
varying vec4 normCoords; 
varying vec4 viewCoords;
varying vec4 viewTangetSpace;
varying vec4 lightTangetSpace;
varying vec4 reflUV;
uniform vec4 lightPos, cameraPos;


void main()
{
	// Because we have a flat plane for water we already know the vectors for tangent space
	vec4 normal = vec4(0.0, 0.0, 1.0, 0.0);
	vec4 tangent = vec4(1.0, 0.0, 0.0, 0.0);
	vec4 biTangent = vec4(0.0, 1.0, 0.0, 0.0);

	// Calculate the vector coming from the vertex to the camera
	vec4 viewDir = cameraPos - gl_Vertex;

	// Compute tangent space for the view direction
	viewTangetSpace.x = dot(viewDir, tangent);
	viewTangetSpace.y = dot(viewDir, biTangent);
	viewTangetSpace.z = dot(viewDir, normal);
	viewTangetSpace.w = 1.0;

	// Calculate the vector that the light hits the vertex
	vec4 lightDir = lightPos - gl_Vertex;

	// Compute tangent space for the light direction
	lightTangetSpace.x = dot(lightDir, tangent);
	lightTangetSpace.y = dot(lightDir, biTangent);
	lightTangetSpace.z = dot(lightDir, normal);
	lightTangetSpace.w = 1.0;

	refrCoords = gl_MultiTexCoord1;
	normCoords = gl_MultiTexCoord2;
	reflUV = gl_MultiTexCoord0;

	// This calculates our current projection coordinates
	viewCoords = gl_ModelViewProjectionMatrix * gl_Vertex;

	gl_Position = viewCoords;
}