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Diffstat (limited to 'resources/shaders/gouraud_light.vs')
-rw-r--r-- | resources/shaders/gouraud_light.vs | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/resources/shaders/gouraud_light.vs b/resources/shaders/gouraud_light.vs new file mode 100644 index 000000000..d4f71938a --- /dev/null +++ b/resources/shaders/gouraud_light.vs @@ -0,0 +1,38 @@ +#version 110 + +#define INTENSITY_CORRECTION 0.6 + +// normalized values for (-0.6/1.31, 0.6/1.31, 1./1.31) +const vec3 LIGHT_TOP_DIR = vec3(-0.4574957, 0.4574957, 0.7624929); +#define LIGHT_TOP_DIFFUSE (0.8 * INTENSITY_CORRECTION) +#define LIGHT_TOP_SPECULAR (0.125 * INTENSITY_CORRECTION) +#define LIGHT_TOP_SHININESS 20.0 + +// normalized values for (1./1.43, 0.2/1.43, 1./1.43) +const vec3 LIGHT_FRONT_DIR = vec3(0.6985074, 0.1397015, 0.6985074); +#define LIGHT_FRONT_DIFFUSE (0.3 * INTENSITY_CORRECTION) + +#define INTENSITY_AMBIENT 0.3 + +// x = tainted, y = specular; +varying vec2 intensity; + +void main() +{ + // First transform the normal into camera space and normalize the result. + vec3 normal = normalize(gl_NormalMatrix * gl_Normal); + + // Compute the cos of the angle between the normal and lights direction. The light is directional so the direction is constant for every vertex. + // Since these two are normalized the cosine is the dot product. We also need to clamp the result to the [0,1] range. + float NdotL = max(dot(normal, LIGHT_TOP_DIR), 0.0); + + intensity.x = INTENSITY_AMBIENT + NdotL * LIGHT_TOP_DIFFUSE; + vec3 position = (gl_ModelViewMatrix * gl_Vertex).xyz; + intensity.y = LIGHT_TOP_SPECULAR * pow(max(dot(-normalize(position), reflect(-LIGHT_TOP_DIR, normal)), 0.0), LIGHT_TOP_SHININESS); + + // Perform the same lighting calculation for the 2nd light source (no specular applied). + NdotL = max(dot(normal, LIGHT_FRONT_DIR), 0.0); + intensity.x += NdotL * LIGHT_FRONT_DIFFUSE; + + gl_Position = ftransform(); +} |