22 lines
834 B
GLSL
22 lines
834 B
GLSL
uniform mat4 u_matrix;
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uniform vec2 u_tl_parent;
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uniform float u_scale_parent;
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uniform float u_buffer_scale;
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layout (location = 0) in vec2 a_pos;
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layout (location = 1) in vec2 a_texture_pos;
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out vec2 v_pos0;
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out vec2 v_pos1;
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void main() {
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gl_Position = u_matrix * vec4(a_pos, 0, 1);
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// We are using Int16 for texture position coordinates to give us enough precision for
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// fractional coordinates. We use 8192 to scale the texture coordinates in the buffer
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// as an arbitrarily high number to preserve adequate precision when rendering.
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// This is also the same value as the EXTENT we are using for our tile buffer pos coordinates,
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// so math for modifying either is consistent.
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v_pos0 = (((a_texture_pos / 8192.0) - 0.5) / u_buffer_scale ) + 0.5;
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v_pos1 = (v_pos0 * u_scale_parent) + u_tl_parent;
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}
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